CN107077915A - Conductive material and connection structure - Google Patents

Abstract

Provided is a conductive material having high dispersibility of conductive particles, enabling efficient placement of solder in the conductive particles on electrodes, and improving electrical conduction reliability between electrodes. The conductive material of the present invention comprises a plurality of conductive particles, a thermosetting compound, and a thermosetting agent. The conductive particles have solder on the outer surface of a conductive portion, and the conductive particles have O—Si bonds on the outer surface of the solder in the conductive portion.

Description

Conductive material and connection structure

technical field

The present invention relates to a conductive material including conductive particles with solder. Moreover, this invention relates to the connection structure using the said electrically-conductive material.

Background technique

Anisotropic conductive materials such as anisotropic conductive paste and anisotropic conductive film are widely known. In the above-mentioned anisotropic conductive material, conductive particles are dispersed in the adhesive.

In order to obtain various connection structures, the above-mentioned anisotropic conductive material is used, for example, in the connection of a flexible printed circuit board and a glass substrate (FOG (Film on Glass)), in the connection of a semiconductor chip and a flexible printed circuit board (COF (Chip on Film) )), the connection between the semiconductor chip and the glass substrate (COG (Chip on Glass)), and the connection between the flexible printed circuit board and the glass epoxy substrate (FOB (Film on Board)), etc.

When electrically connecting, for example, electrodes of a flexible printed circuit board and electrodes of a glass epoxy substrate using the aforementioned anisotropic conductive material, the anisotropic conductive material containing conductive particles is disposed on the glass epoxy substrate. Next, the flexible printed circuit boards are stacked, and heated and pressed. Thereby, the anisotropic conductive material is hardened, between electrodes are electrically connected via electroconductive particle, and the connection structure is obtained.

As an example of the aforementioned anisotropic conductive material, the following Patent Document 1 describes an anisotropic conductive material including conductive particles and a resin component that does not complete curing at the melting point of the conductive particles. Specific examples of the conductive particles include tin (Sn), indium (In), bismuth (Bi), silver (Ag), copper (Cu), zinc (Zn), lead (Pb), cadmium (Cd ), gallium (Ga), silver (Ag) and thallium (Tl) and other metals or alloys of these metals.

In Patent Document 1, it is described that the electrodes are electrically connected through a resin heating step and a resin component curing step. In this resin heating step, the anisotropic conductive resin is heated to a temperature higher than the melting point of the conductive particles and does not The temperature at which the above-mentioned resin component is cured, and in this resin component curing step, the above-mentioned resin component is cured. In addition, Patent Document 1 describes mounting with a temperature profile shown in FIG. 8 of Patent Document 1. In Patent Document 1, the conductive particles are melted in the resin component that is not cured at the temperature at which the anisotropic conductive resin is heated.

Patent Document 2 below discloses an adhesive tape comprising a resin layer having a thermosetting resin, solder powder, and a curing agent, wherein the solder powder and the curing agent are present in the resin layer. This adhesive tape is in the form of a film, not a paste.

In addition, Patent Document 2 discloses a bonding method using the above-mentioned adhesive tape. Specifically, the first substrate, the adhesive tape, the second substrate, the adhesive tape, and the third substrate were stacked in order from below to obtain a laminated body. At this time, the first electrode provided on the surface of the first substrate and the second electrode provided on the surface of the second substrate are opposed to each other. In addition, the second electrode provided on the surface of the second substrate faces the third electrode provided on the surface of the third substrate. Then, the laminate is bonded by heating at a predetermined temperature. Thus, a connected structure is obtained.

In addition, the following Patent Document 3 discloses a method in which a semiconductor chip having a plurality of connection terminals and a wiring board having a plurality of electrode terminals are arranged to face each other, and the electrode terminals of the wiring board are connected to the semiconductor chip. A flip-chip mounting method for the electrical connection of the above-mentioned connecting terminals. This flip-chip mounting method includes: (1) a step of supplying solder powder and a resin with a convective additive to the surface of the wiring board having the electrode terminals; (2) a step of bringing the semiconductor chip into contact with the surface of the resin; 3) a step of heating the wiring board to a temperature at which the solder powder melts, and (4) a step of curing the resin after the heating step. In the heating step (3) of the wiring board, a connection body electrically connecting the electrode terminals and the connection terminals is formed, and in the curing step (4) of the resin, the semiconductor chip is fixed to the wiring board.

prior art literature

patent documents

Patent Document 1: Japanese Patent Laid-Open No. 2004-260131

Patent Document 2: WO2008/023452A1

Patent Document 3: Japanese Patent Laid-Open No. 2006-114865

Contents of the invention

In an anisotropic conductive paste containing conventional solder powder or conductive particles having a solder layer on the surface, it may not be possible to efficiently arrange solder powder or conductive particles on electrodes (wires). In conventional solder powder or conductive particles, the moving speed of the solder powder or conductive particles to the electrodes may be slow.

Also, when using the anisotropic conductive material described in Patent Document 1 and electrically connecting electrodes by the method described in Patent Document 1, conductive particles containing solder may not be efficiently disposed on electrodes (wires). In addition, in the examples of Patent Document 1, in order to sufficiently move the solder at a temperature equal to or higher than the melting point of the solder and keep the temperature constant, the manufacturing efficiency of the connection structure decreases. If mounting is performed with the temperature profile shown in FIG. 8 of patent document 1, the manufacturing efficiency of a connection structure will fall.

In patent document 2, there is no concrete description about the electroconductive particle used for an anisotropic electrically-conductive material. In the example of patent document 3, the copper layer was formed on the surface of the resin particle, and the electroconductive particle which formed the solder layer on the surface of this copper layer was used. The center part of this electroconductive particle consists of resin particle. Moreover, when using the anisotropic electrically-conductive material described in patent document 2, 3, it may become difficult to arrange|position electroconductive particle efficiently on an electrode (wire), and the positional displacement between the upper and lower electrodes which should be connected may generate|occur|produce.

Moreover, in the conventional anisotropic conductive material, the dispersibility of electroconductive particle may be low. Therefore, when using an anisotropic electrically-conductive material after storage, it may become more difficult to arrange|position electroconductive particle on an electrode (wire).

An object of the present invention is to provide a conductive material having high dispersibility of conductive particles in a conductive material, enabling efficient placement of solder in conductive particles on electrodes, and improving conduction reliability between electrodes. Another object of the present invention is to provide a connection structure using the above-mentioned conductive material.

means to solve the problem

According to a broad aspect of the present invention, there is provided a conductive material comprising a plurality of conductive particles, a thermosetting compound, and a thermosetting agent, wherein the conductive particles have solder on the outer surface portion of the conductive part, and the conductive particles are in the above-mentioned The outer surface of the said solder of a conductive part has an O-Si bond.

On the specific situation of the electrically-conductive material which concerns on this invention, the said electroconductive particle has a Sn-O-Si bond in the outer surface of the said solder of the said electroconductive part.

In a specific aspect of the conductive material of the present invention, it is a surface treatment product based on a silane coupling agent.

On the specific situation of the electrically-conductive material which concerns on this invention, the said electroconductive particle has an amino group on the outer surface of the said solder of the said electroconductive part.

On the specific situation of the electrically-conductive material which concerns on this invention, the said electroconductive particle has the group containing a carboxyl group via Sn—O—Si bond on the outer surface of the said solder of the said electroconductive part.

On the specific aspect of the electrically conductive material of this invention, the said electroconductive particle is a solder particle.

On a certain specific aspect of the electrically conductive material of this invention, the average particle diameter of the said electroconductive particle is 1 micrometer or more and 60 micrometers or less.

In a specific aspect of the electrically conductive material of this invention, content of the said electroconductive particle is 10 weight% or more and 80 weight% or less in 100 weight% of electrically conductive materials.

According to a broad aspect of the present invention, there is provided a connection structure including: a first connection object member having a first electrode on its surface; a second connection object member having a second electrode on its surface; The first connection object member is connected to the second connection object member, the material of the connection portion is the conductive material, and the first electrode and the second electrode are electrically connected by solder in the conductive particles.

Invention effect

The conductive material of the present invention includes a plurality of conductive particles, a thermosetting compound, and a thermosetting agent, the conductive particles have solder on the outer surface of the conductive part, and the conductive particles have solder on the outer surface of the solder of the conductive part. Since it has an O-Si bond, the dispersibility of the electroconductive particle in a conductive material is high, the solder in electroconductive particle can be efficiently arrange|positioned on an electrode, and the conduction reliability between electrodes can be improved.

Description of 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.

2( a ) to ( c ) are cross-sectional views for explaining each step of an example of a method of manufacturing a connection structure using the conductive material according to the embodiment of the present invention.

Fig. 3 is a cross-sectional view showing a modified example of the connection structure.

Fig. 4 is a cross-sectional view showing a first example of conductive particles that can be used as a conductive material.

Fig. 5 is a cross-sectional view showing a second example of conductive particles that can be used as a conductive material.

Fig. 6 is a cross-sectional view showing a third example of conductive particles that can be used as a conductive material.

detailed description

Hereinafter, details of the present invention will be described.

(conductive material)

The conductive material of the present invention contains a plurality of conductive particles, a thermosetting compound, and a thermosetting agent. The said electroconductive particle has an electroconductive part. The said electroconductive particle has solder in the outer surface part of an electroconductive part. Solder is contained in the conductive part and is part or all of the conductive part.

In the electrically-conductive material of this invention, the said electroconductive particle has an O-Si bond in the outer surface of the said solder of the said electroconductive part.

In the present invention, since specific conductive particles are included in the conductive material, corrosion of solder can be suppressed favorably. In the present invention, since the above-mentioned structure is provided, when the electrodes are electrically connected, the solder in the conductive particles is easily concentrated between the upper and lower opposing electrodes, and the solder in the conductive particles can be efficiently arranged. on the electrodes (wires). Moreover, a part of the solder in electroconductive particle is hard to be arrange|positioned in the area|region (space) where an electrode is not formed, and the quantity of the solder arrange|positioned in the area|region where an electrode is not formed can be reduced considerably. In this invention, the electroconductive particle which is not located between opposing electrodes can be efficiently moved between opposing electrodes. Therefore, the conduction reliability between electrodes can be improved. In addition, electrical connection between electrodes adjacent in the lateral direction that cannot be connected can be prevented, and insulation reliability can be improved.

Furthermore, in this invention, the dispersibility of the electroconductive particle in a conductive material is high, and the storage stability of a conductive material is excellent. Moreover, in this invention, corrosion of the solder in electroconductive particle also becomes difficult to progress. Therefore, the solder in the electroconductive particles can be efficiently arranged on the electrodes regardless of whether it is before storage or after storage of the conductive material, and the conduction reliability between electrodes can be improved.

Furthermore, in the present invention, positional displacement between electrodes can be prevented. In the present invention, when the second connection object member is superimposed on the first connection object member on which the conductive material is arranged on the upper surface, even if the electrodes of the first connection object member and the electrodes of the second connection object member are aligned In the state where the deviation occurs, if the first connection object part is overlapped with the second connection object part, the deviation can also be corrected, so that the electrodes of the first connection object part and the electrodes of the second connection object part are connected (self-positioning). effect).

It is preferable that the said electroconductive particle has a Sn-O-Si bond on the outer surface of the said solder of the said electroconductive part from a viewpoint of effectively improving dispersibility and the arrangement|positioning precision of a solder.

From the viewpoint of effectively improving the dispersibility and the arrangement accuracy of the solder, the above-mentioned conductive particles are preferably obtained by surface treatment using a silane coupling agent, and the above-mentioned conductive particles are preferably surface-treated with a silane coupling agent. deal with. That is, it is preferable that the said electroconductive particle is a surface-treated thing by a silane coupling agent.

The said electroconductive particle may be a solder particle. The above-mentioned solder particles are formed of solder. The said solder particle has solder on the outer surface part of a conductive part. Both the central portion of the solder particle and the outer surface portion of the conductive portion are formed of solder, and both the central portion and the outer surface portion of the conductive portion are particles that are solder. The said electroconductive particle may have a base material particle and the electroconductive part arrange|positioned on the surface of this base material particle. In this case, the said electroconductive particle has solder in the outer surface part of an electroconductive part.

Moreover, compared with the case of using the conductive particle equipped with the said solder particle, when using the conductive particle provided with the base material particle which is not formed with solder, and the solder part arrange|positioned on the surface of the base material particle, electroconductive The conductive particles are difficult to accumulate on the electrodes, and the solder bondability between the conductive particles is low. Therefore, the conductive particles moving on the electrodes tend to move out of the electrodes, and the effect of suppressing positional displacement between the electrodes may also be reduced. trend. Therefore, it is preferable that the said electroconductive particle is the solder particle formed by solder.

In order to more efficiently arrange the solder on the electrodes, the viscosity (η25) of the conductive material at 25° C. is preferably 10 Pa·s or higher, more preferably 50 Pa·s or higher, still more preferably 100 Pa·s or higher, and Preferably it is 800 Pa·s or less, more preferably 600 Pa·s or less, still more preferably 500 Pa·s or less.

The above-mentioned viscosity (η25) can be appropriately adjusted depending on the types and amounts of the ingredients to be blended. In addition, the viscosity can be made relatively high through the use of fillers.

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

The above-mentioned conductive material can be used as a conductive paste, a conductive film, and the like. The above-mentioned conductive paste is preferably an anisotropic conductive paste, and the above-mentioned conductive film is preferably an anisotropic conductive film. It is preferable that the said electrically-conductive material is an anisotropic electrically-conductive paste from a viewpoint of disposing the solder in electroconductive particle more efficiently on an electrode. The above-mentioned conductive materials are suitable for electrical connection of electrodes. The above-mentioned conductive material is preferably a circuit connection material.

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

(conductive particles)

The said electroconductive particle electrically connects between electrodes of a connection object member. The said electroconductive particle has solder in the outer surface part of an electroconductive part. The said electroconductive particle has an O-Si bond on the outer surface of the said solder of the said electroconductive part. Regarding the O—Si bond present on the outer surface of the solder in the conductive portion, for example, components of the solder (atoms constituting the solder) are bonded to oxygen atoms of the O—Si bond. The said electroconductive particle has (component of solder)-O-Si bond ((atom which comprises solder)-O-Si bond) on the outer surface of the said solder of the said electroconductive part, for example.

From the standpoint of further improving the dispersibility of the conductive particles, disposing the solder on the electrodes more efficiently, and further suppressing positional displacement between the electrodes, it is preferable that the conductive particles have Sn-O-Si bond.

The hydroxyl groups on the surface of the solder can be reacted with the silane coupling agent. O—Si bonds can be formed by reacting the silane coupling agent with the hydroxyl groups on the surface of the solder.

It is preferable to perform surface treatment using a silane coupling agent to obtain conductive particles having Sn—O—Si bonds on the outer surface of the solder of the conductive portion, and then, the conductive particles, a thermosetting compound, and heat The curing agent is mixed, whereby the above-mentioned conductive material is obtained.

From the viewpoint of further improving the dispersibility of the conductive particles, more efficiently disposing the solder on the electrodes, and further suppressing positional displacement between the electrodes, it is preferable that the above-mentioned conductive particles are on the outer surface of the above-mentioned solder of the above-mentioned conductive part. With amino.

From the viewpoint of further improving the dispersibility of the conductive particles, more efficiently disposing the solder on the electrodes, and further suppressing positional displacement between the electrodes, it is preferable that the above-mentioned conductive particles are on the outer surface of the above-mentioned solder of the above-mentioned conductive part. It has a group containing a carboxyl group via an O—Si bond, and it is more preferable to have a group containing a carboxyl group via a Sn—O—Si bond on the outer surface of the solder in the conductive portion. In particular, due to the presence of carboxyl-containing groups, the agglomeration performance of solder is considerably improved.

From the standpoint of further improving the dispersibility of the conductive particles, more efficiently disposing the solder on the electrodes, and further suppressing positional displacement between the electrodes, the conductive particles are preferably surface-treated with a silane coupling agent, Obtained by introducing a carboxyl-containing group. A group containing a carboxyl group can be introduced into the residue that the silane coupling agent has. The above-mentioned conductive particles preferably have a group derived from a silane coupling agent and a carboxyl group, and it is preferable that the solder and the group containing a carboxyl group are connected via a group derived from a silane coupling agent.

It is preferable that the said silane coupling agent has an organic functional group and an alkoxy group in 1 molecule, and it is preferable that this organic functional group can react with the compound which has a group containing a carboxyl group. As said alkoxy group, a methoxy group, an ethoxy group, etc. are mentioned. As said silane coupling agent, the silane coupling agent which has an epoxy group, the silane coupling agent which has an amino group, the silane coupling agent which has an isocyanate group, etc. are mentioned. It is preferable that the said silane coupling agent is a silane coupling agent which has an amino group from a viewpoint of disposing the solder in electroconductive particle more efficiently on an electrode. The above-mentioned silane coupling agents may be used alone or in combination of two or more. Moreover, when the said electroconductive particle has an amino group on the outer surface of the said solder of the said electroconductive part, it does not need to be the amino group derived from the silane coupling agent which has this amino amino group.

KBM-303, KBM-402, KBM-403, KBE-402, KBE-403 etc. made by Shin-Etsu Chemical Co., Ltd. are mentioned as a silane coupling agent which has the said epoxy group. KBM-602, KBM-603, KBM-903, etc. are mentioned as a silane coupling agent which has the said amino group. KBE-9007 etc. are mentioned as a silane coupling agent which has the said isocyanate group.

As the compound for introducing the above-mentioned carboxyl group-containing group, levulinic acid, glutaric acid, glycolic acid, succinic acid, malic acid, oxalic acid, malonic acid, adipic acid, 5-oxohexanoic acid, 3 -Hydroxypropionic acid, 4-aminobutyric acid, 3-mercaptopropionic acid, 3-mercaptoisobutyric acid, 3-methylthiopropionic acid, 3-phenylpropionic acid, 3-phenylisobutyric acid, 4-benzene Butyric acid, capric acid, lauric acid, myristic acid, pentadecanoic acid, hexadecanoic acid, 9-unsaturated fatty acid, heptadecanoic acid, palmitic acid, oleic acid, octadecenoic acid, linoleic acid acid, (9,12,15)-linolenic acid, nonadecanoic acid, eicosanoic acid, sebacic acid and dodecanedioic acid, etc. Preferred are glutaric, adipic or glycolic acids. The compound for introducing the above-mentioned carboxyl group-containing group may be used alone or in combination of two or more.

As a specific method for obtaining conductive particles having an O-Si bond on the outer surface of the solder, a method in which conductive particles and a silane coupling agent are placed in a low-polarity solvent such as toluene to perform dealcoholization reaction Wait.

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

Fig. 4 is a cross-sectional view showing a first example of conductive particles that can be used as a conductive material.

The electroconductive particle 21 shown in FIG. 4 is a solder particle. The whole electroconductive particle 21 is formed with solder. The electroconductive particle 21 is not a core-shell particle which has a base material particle in a core. Both the center part of the electroconductive particle 21 and the outer surface part of a conductive part are formed with solder.

Fig. 5 is a cross-sectional view showing a second example of conductive particles that can be used as a conductive material.

The electroconductive particle 31 shown in FIG. 5 is equipped with the electroconductive part 33 arrange|positioned on the surface of the base material particle 32 and the base material particle 32. The conductive part 33 covers the surface of the substrate particle 32 . The electroconductive particle 31 is a coating particle which the surface of the base material particle 32 was covered with the electroconductive part 33.

The conductive portion 33 has a second conductive portion 33A and a solder portion 33B (first conductive portion). The electroconductive particle 31 is equipped with the 2nd electroconductive part 33A between the base material particle 32 and the solder part 33B. Therefore, the electroconductive particle 31 is equipped with the 2nd electroconductive part 33A arrange|positioned on the surface of the base material particle 32, the base material particle 32, and the solder part 33B arrange|positioned on the outer surface of 33 A of 2nd electroconductive parts.

Fig. 6 is a cross-sectional view showing a third example of conductive particles that can be used as a conductive material.

As mentioned above, the electroconductive part 33 in the electroconductive particle 31 has a two-layer structure. The electroconductive particle 41 shown in FIG. 6 has the solder part 42 as a single-layer electroconductive part. The electroconductive particle 41 is equipped with the solder part 42 arrange|positioned on the surface of the base material particle 32 and the base material particle 32.

Examples of the substrate particles include resin particles, inorganic particles other than metal particles, organic-inorganic hybrid particles, metal particles, and the like. The aforementioned substrate particles are preferably substrate particles other than metal particles, and are preferably resin particles, inorganic particles other than metal particles, or organic-inorganic hybrid particles. The above-mentioned base particles may be copper particles. The aforementioned substrate particle may have a core and a shell disposed on the surface of the core, or may be a core-shell particle. The aforementioned core may also be an organic core, and the aforementioned shell may also be an inorganic shell.

Various organic substances can be preferably used as the resin for forming the above-mentioned resin particles. Examples of the resin used to form the above-mentioned resin particles include polyolefin resins such as polyethylene, polypropylene, polystyrene, polyvinyl chloride, polyvinylidene chloride, polyisobutylene, and polybutadiene; polymethyl methacrylate , polymethyl acrylate and other acrylic resins; polycarbonate, polyamide, phenol formaldehyde resin, melamine formaldehyde resin, benzoguanamine formaldehyde resin, urea formaldehyde resin, phenolic resin, melamine resin, benzoguanamine resin, urea formaldehyde resin, Epoxy resin, unsaturated polyester resin, saturated polyester resin, polyethylene terephthalate, polysulfone, polyphenylene ether, polyacetal, polyimide, polyamideimide, polyetherether Ketones, polyethersulfones, divinylbenzene polymers, and divinylbenzene copolymers, etc. As said divinylbenzene type copolymer etc., a divinylbenzene-styrene copolymer, a divinylbenzene-(meth)acrylate copolymer, etc. are mentioned. Since the hardness of the above-mentioned resin particles can be easily controlled within an appropriate range, the resin used to form the above-mentioned resin particles is preferably formed by polymerizing one or more polymerizable monomers having ethylenically unsaturated groups. made polymers.

When polymerizing a polymerizable monomer having an ethylenically unsaturated group to obtain the above-mentioned resin particles, examples of the polymerizable monomer having the ethylenically unsaturated group include non-crosslinkable monomers and crosslinkable monomers. of monomers.

Examples of the non-crosslinkable monomer include: styrene-based 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 Alkyl (meth)acrylates such as cetyl (meth)acrylate, stearyl (meth)acrylate, cyclohexyl (meth)acrylate, isobornyl (meth)acrylate, etc.; 2-hydroxyethyl (meth)acrylate, glycerol (meth)acrylate, polyoxyethylene (meth)acrylate, glycidyl (meth)acrylate and other (meth)acrylates containing oxygen atoms; Nitrile-containing monomers such as (meth)acrylonitrile; vinyl ethers such as methyl vinyl ether, ethyl vinyl ether, and propyl vinyl ether; vinyl acetate, vinyl butyrate, vinyl laurate, hard Vinyl esters such as fatty acid vinyl esters; unsaturated hydrocarbons such as ethylene, propylene, isoprene, butadiene; trifluoromethyl (meth)acrylate, pentafluoroethyl (meth)acrylate, vinyl chloride, Halogen-containing monomers such as vinyl fluoride and chlorostyrene, etc.

Examples of the crosslinkable monomer include tetramethylolmethane tetra(meth)acrylate, tetramethylolmethane tri(meth)acrylate, tetramethylolmethane di(methyl) Acrylates, trimethylolpropane tri(meth)acrylate, dipentaerythritol hexa(meth)acrylate, dipentaerythritol penta(meth)acrylate, glyceryl tri(meth)acrylate, glyceryl di(meth)acrylate ) acrylate, (poly)ethylene glycol di(meth)acrylate, (poly)propylene glycol di(meth)acrylate, (poly)tetramethylene di(meth)acrylate, 1,4-butyl Polyfunctional (meth)acrylates such as diol di(meth)acrylate; triallyl (iso)cyanurate, triallyl trimellitate, divinylbenzene, diene phthalate Propyl ester, diallyl acrylamide, diallyl ether, γ-(meth)acryloxypropyltrimethoxysilane, trimethoxysilylstyrene, vinyltrimethoxysilane, etc. Silane monomer, etc.

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

When the above-mentioned substrate particles are inorganic particles other than metals or organic-inorganic hybrid particles, examples of the inorganic substance used to form the above-mentioned substrate particles include silica, alumina, barium titanate, zirconia, and carbon black etc. The above-mentioned inorganic substances are preferably not metals. The particles formed using the above-mentioned silica are not particularly limited, but for example, cross-linked polymer particles are formed by hydrolyzing a silicon compound having two or more hydrolyzable alkoxysilyl groups, and then, if necessary, Particles obtained by firing. As said organic-inorganic hybrid particle, the organic-inorganic hybrid particle etc. which consist of a crosslinked alkoxysilyl polymer and an acrylic resin are mentioned, for example.

The above-mentioned organic-inorganic hybrid particles are preferably core-shell type organic-inorganic hybrid particles having a core and a shell arranged on the surface of the core. The aforementioned core is preferably an organic core. The aforementioned shell is preferably an inorganic shell. From the viewpoint of effectively reducing connection resistance between electrodes, the substrate particle is preferably an organic-inorganic hybrid particle having an organic core and an inorganic shell disposed on the surface of the organic core.

As a material for forming the said organic core, the resin etc. which are used for forming the said resin particle are mentioned.

Examples of the material used to form the above-mentioned inorganic shell include inorganic substances used to form the above-mentioned substrate particles. The material for forming the above-mentioned inorganic shell is preferably silica. The inorganic shell is preferably formed by forming a shell of a metal alkoxide on the surface of the core by a sol-gel method, and then sintering the shell. The aforementioned metal alkoxide is preferably an alkoxysilane. The above-mentioned inorganic shell is preferably formed of alkoxysilane.

The particle diameter of the above-mentioned core is preferably 0.5 μm or more, more preferably 1 μm or more, and preferably 100 μm or less, more preferably 60 μm or less, still more preferably 30 μm or less, particularly preferably 15 μm or less, most preferably It is 10 μm or less. Electroconductive particles more suitable for electrical connection between electrodes are obtained as the particle diameter of the said core is more than the said minimum and below the said upper limit, and substrate particle can be suitably used for the use of electroconductive particle. For example, if the particle size of the core is more than the above-mentioned lower limit and below the above-mentioned upper limit, when the electrodes are connected using the above-mentioned conductive particles, the contact area between the conductive particles and the electrodes becomes sufficiently large, and it is difficult to form a conductive layer. Agglomerated conductive particles are formed. Moreover, the distance between the electrodes connected via electroconductive particle does not become too large, and a conductive layer is hard to peel from the surface of a base material particle.

The particle size of the core means a diameter when the core is a true spherical shape, and means a maximum diameter when the core is a shape other than a true spherical shape. In addition, the particle diameter of a core means the average particle diameter measured with the arbitrary particle diameter measuring apparatus of a core. For example, a particle size distribution measuring machine using principles such as laser light scattering, resistance value change, and image analysis after shooting can be used.

The thickness of the above shell is preferably 100 nm or more, more preferably 200 nm or more, and preferably 5 μm or less, more preferably 3 μm or less. Electroconductive particle more suitable for the electrical connection between electrodes is obtained as the thickness of the said shell is more than the said minimum and below the said upper limit, and substrate particle can be used suitably for the use of electroconductive particle. The thickness of the above-mentioned shell is the average thickness of each substrate particle. The thickness of the shell can be controlled by the control of the sol-gel method.

When the said base material particle is a metal particle, silver, copper, nickel, silicon, gold, titanium etc. are mentioned as a metal used for forming this metal particle. When the above-mentioned substrate particles are metal particles, the metal particles are preferably copper particles. Among them, the above-mentioned substrate particles are preferably not metal particles.

The particle size of the substrate particles is preferably 0.1 μm or more, more preferably 1 μm or more, even more preferably 1.5 μm or more, particularly preferably 2 μm or more, and preferably 100 μm or less, more preferably 60 μm or less, More preferably, it is 30 μm or less, more preferably 20 μm or less, still more preferably 10 μm or less, particularly preferably 5 μm or less, and most preferably 3 μm or less. If the particle diameter of the above-mentioned substrate particle is more than the above-mentioned lower limit, the contact area of the electroconductive particle and the electrode becomes large, so the conduction reliability between the electrodes can be further improved, and the friction between the electrodes connected via the electroconductive particle can be further reduced. Connect the resistor. Electroconductive particle can be fully compressed easily that the particle diameter of the said base material particle is below the said upper limit, the connection resistance between electrodes can be reduced more, and the space|interval between electrodes can be made smaller further.

The particle diameter of the above-mentioned substrate particle represents the diameter when the substrate particle is a perfect spherical shape, and represents the maximum diameter when the substrate particle is not a perfect spherical shape.

The particle size of the substrate particles is particularly preferably 2 μm or more and 5 μm or less. When the particle diameter of the said base material particle exists in the range of 2 micrometers or more and 5 micrometers or less, the space|interval between electrodes can be made smaller, and even if it thickens the thickness of a conductive layer, small electroconductive particle can be obtained.

The method of forming the conductive portion on the surface of the substrate particle and the method of forming the solder portion on the surface of the substrate particle or the surface of the second conductive portion are not particularly limited. As a method of forming the above-mentioned conductive part and the above-mentioned solder part, for example, a method based on electroless plating, a method based on electroplating, a method based on physical collision, a method based on mechanochemical reaction, a method based on physical vapor deposition or physical adsorption method, and a method of applying metal powder or a paste containing metal powder and a binder to the surface of the substrate particles. Among them, electroless plating, electroplating, or a method under physical collision is preferable. As a method based on said physical vapor deposition, methods, such as vacuum vapor deposition, ion plating, and ion sputtering, are mentioned. In addition, in the method based on the above-mentioned physical collision, for example, ThetaComposer (manufactured by Tokusu Works Co., Ltd.) or the like can be used.

The melting point of the substrate particles is preferably higher than the melting points of the conductive portion and the solder portion. 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, particularly preferably higher than 450°C. In addition, the melting point of the substrate particles may be lower than 400°C. The melting point of the substrate particles may be 160°C or lower. The softening point of the above-mentioned substrate particles is preferably 260° C. or higher. The softening point of the said substrate particle may be less than 260 degreeC.

The said electroconductive particle may have a single-layer solder part. The said electroconductive particle may have a multilayer electroconductive part (solder part, a 2nd electroconductive part). That is, in the said electroconductive particle, you may laminate|stack two or more electroconductive parts. When the said electroconductive part is two or more layers, it is preferable that the said electroconductive particle has a solder in the outer surface part of an electroconductive part.

The aforementioned solder is preferably a metal having a melting point of 450° C. or lower (low melting point metal). The solder portion is preferably a metal layer (low melting point metal layer) having a melting point of 450° C. or lower. The above-mentioned low-melting-point metal layer is a layer containing a low-melting-point metal. It is preferable that the solder in the said electroconductive particle is the metal particle (low melting point metal particle) whose melting point is 450 degreeC or less. The above-mentioned low-melting-point metal particles are particles containing a low-melting-point metal. The low melting point metal means 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. Moreover, it is preferable that the solder in the said electroconductive particle contains tin. In 100% by weight of the metal contained in the above-mentioned solder portion and in 100% by weight of the metal contained in the solder in the above-mentioned conductive particles, the content of tin is preferably 30% by weight or more, more preferably 40% by weight or more, and even more preferably 40% by weight or more. It is preferably 70% by weight or more, particularly preferably 90% by weight or more. The conduction|electrical_connection reliability of electroconductive particle and an electrode will improve more that content of tin contained in the solder in the said electroconductive particle is more than the said minimum.

In addition, the above tin content can be determined using a high-frequency inductively coupled plasma emission spectrometer ("ICP-AES" manufactured by Horiba Corporation), or a fluorescent X-ray segment analyzer ("EDX" manufactured by Shimadzu Corporation). -800HS") and so on.

By using the electroconductive particle which has the said solder on the outer surface part of a conductive part, a solder melt|dissolves and joins an electrode, and a solder conducts between electrodes. For example, since the solder and the electrodes are likely to be in surface contact rather than point contact, the connection resistance is reduced. In addition, by using conductive particles having solder on the outer surface of the conductive part, the bonding strength between the solder and the electrode increases, and as a result, peeling between the solder and the electrode becomes less likely to occur, and conduction reliability can be effectively improved.

The low-melting-point metal constituting the solder portion and 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 tin-silver alloys, tin-copper alloys, tin-silver-copper alloys, tin-bismuth alloys, tin-zinc alloys, and tin-indium alloys. Among them, tin, tin-silver alloys, tin-silver-copper alloys, tin-bismuth alloys, and tin-indium alloys are preferable for the above-mentioned low-melting-point metals because they have excellent wettability to electrodes. More preferred are tin-bismuth alloys and tin-indium alloys.

The material constituting the above-mentioned solder (solder portion) is preferably a filler metal whose liquidus line is 450° C. or lower based on JIS Z3001: Soldering Terminology. As a composition of the said solder, the metal composition containing zinc, gold, silver, lead, copper, tin, bismuth, indium, etc. is mentioned, for example. Among them, tin-indium-based (117° C. eutectic) or tin-bismuth-based (139° C. eutectic) which are low-melting and lead-free are preferable. That is, the above-mentioned solder preferably does not contain lead, and is preferably a solder containing tin and indium, or a solder containing tin and bismuth.

In order to further improve the bonding strength between the above-mentioned solder and electrodes, the solder in the above-mentioned conductive particles may contain nickel, copper, antimony, aluminum, zinc, iron, gold, titanium, phosphorus, germanium, tellurium, cobalt, bismuth, manganese, chromium, Molybdenum, palladium and other metals. Moreover, it is preferable that the solder in the said electroconductive particle contains nickel, copper, antimony aluminum, or zinc from a viewpoint of improving the joint strength of solder and an electrode further. From the viewpoint of further improving the joint strength between the solder and the electrode in the solder portion or the conductive particles, the content of these metals for improving the joint strength is preferably 0.0001% by weight in 100% by weight of the solder in the above-mentioned conductive particles. above, and preferably 1% by weight or less.

The melting point of the second conductive portion is preferably higher than the melting point of the solder portion. The melting point of the above-mentioned second conductive portion is preferably higher than 160°C, more preferably higher than 300°C, even more preferably higher than 400°C, even more preferably higher than 450°C, particularly preferably higher than 500°C, and most preferably is over 600°C. Since the above-mentioned solder portion has a low melting point, it melts during the conductive connection. It is preferable that the second conductive portion does not melt during conductive connection. It is preferable to melt the said electroconductive particle and use a solder, It is preferable to use it by melting the said solder part, It is preferable to use it by melting the said solder part, and not melting the said 2nd electroconductive part. By making the melting point of the second conductive portion higher than the melting point of the solder portion, only the solder portion can be melted without melting the second conductive portion during conductive connection.

The absolute value of the difference between the melting point of the solder portion and the melting point of the second conductive portion exceeds 0° C., preferably 5° C. or higher, more preferably 10° C. or higher, still more preferably 30° C. or higher, particularly preferably 50° C. °C or higher, most preferably 100 °C or higher.

It is preferable that the said 2nd electroconductive part contains metal. The metal constituting the second conductive portion is not particularly limited. Examples of the metal include gold, silver, copper, platinum, palladium, zinc, lead, aluminum, cobalt, indium, nickel, chromium, titanium, antimony, bismuth, germanium, cadmium, and alloys thereof. In addition, tin-doped indium oxide (ITO) can also be used as the above-mentioned metal. The above-mentioned metals may be used alone or in combination of two or more.

The above-mentioned second conductive part is preferably a nickel layer, a palladium layer, a copper layer or a gold layer, more preferably a nickel layer or a gold layer, and even more preferably a copper layer. The conductive particles preferably have a nickel layer, a palladium layer, a copper layer, or a gold layer, more preferably have a nickel layer or a gold layer, and still more preferably have a copper layer. The connection resistance between electrodes can be further reduced by using the electroconductive particle which has these preferable electroconductive parts for connection between electrodes. In addition, the solder portion can be formed more easily on the surface of these preferable conductive portions.

The thickness of the solder portion is preferably 0.005 μm or more, more preferably 0.01 μm or more, and preferably 10 μm or less, more preferably 1 μm or less, and still more preferably 0.3 μm or less. Sufficient electroconductivity will be acquired as the thickness of a solder part is more than the said minimum and below the said upper limit, and electroconductive particle will fully deform|transform electroconductive particle at the time of connection between electrodes, without becoming hard too much.

The average particle diameter of the conductive particles is preferably 0.5 μm or more, more preferably 1 μm or more, more preferably 3 μm or more, particularly preferably 5 μm or more, and preferably 100 μm or less, more preferably 60 μm or less, More preferably, it is 40 μm or less, more preferably 30 μm or less, still more preferably 20 μm or less, particularly preferably 15 μm or less, and most preferably 10 μm or less. Electroconductive particle can be arrange|positioned on an electrode more efficiently as the average particle diameter of the said electroconductive particle is more than the said minimum and below the said upper limit. The average particle diameter of the said electroconductive particle is especially preferable that it is 3 micrometers or more and 30 micrometers or less.

The "average particle diameter" of the said electroconductive particle shows a number average particle diameter. The average particle diameter of electroconductive particle can be calculated|required by observing 50 arbitrary electroconductive particles with an electron microscope or an optical microscope, calculating an average value, or performing a laser-diffraction particle size distribution measurement, for example.

The coefficient of variation of the particle diameter of the conductive particles is preferably 5% or more, preferably 10% or more, and is preferably 40% or less, more preferably 30% or less. Solder can be arrange|positioned on an electrode more efficiently as the coefficient of variation of the said particle diameter is more than the said minimum and below the said upper limit. However, the variation coefficient of the particle diameter of the said electroconductive particle may be less than 5%.

The above-mentioned coefficient of variation (CV value) is represented by the following formula.

CV value (%)=(ρ/Dn)×100

ρ: standard deviation of particle diameter of conductive particles

Dn: Average value of particle diameters of conductive particles

The shape of the said electroconductive particle is not specifically limited. The shape of the said electroconductive particle may be spherical, and shapes other than a spherical shape, such as a flat shape, may be sufficient.

In 100% by weight of the above-mentioned conductive material, the content of the above-mentioned conductive particles is preferably 1% by weight or more, more preferably 2% by weight or more, more preferably 10% by weight or more, particularly preferably 20% by weight or more, It is most preferably 30% by weight or more, and preferably 80% by weight or less, more preferably 60% by weight or less, and still more preferably 50% by weight or less. When the content of the above-mentioned conductive particles is more than the above-mentioned lower limit and below the above-mentioned upper limit, the conductive particles can be more efficiently arranged on the electrodes, and a large number of conductive particles can be easily arranged between the electrodes, and the conduction reliability can be further improved. . From a viewpoint of further improving conduction reliability, it is preferable that there are many content of the said electroconductive particle.

(thermosetting compound: thermosetting component)

The above-mentioned thermosetting compound is a compound that can be cured by heating. Examples of the above-mentioned thermosetting compounds include: oxetane compounds, epoxy compounds, episulfide compounds, (meth)acrylic compounds, phenol compounds, amino compounds, unsaturated polyester compounds, polyurethane compounds, poly Silicone compounds and polyimide compounds, etc. Among these, epoxy compounds are preferable from the viewpoint of further improving curability and viscosity of the conductive material and further improving connection reliability. The above-mentioned thermosetting compounds may be used alone or in combination of two or more.

An aromatic epoxy compound is mentioned as said epoxy compound. Among these, crystalline epoxy compounds such as resorcinol-type epoxy compounds, naphthalene-type epoxy compounds, biphenyl-type epoxy compounds, and benzophenone-type epoxy compounds are preferable. Preferable is an epoxy compound that is solid at normal temperature (23° C.) and whose melting temperature is not higher than the melting point of solder. The melting temperature is preferably 100°C or lower, more preferably 80°C or lower, and preferably 40°C or higher. By using the above-mentioned preferable epoxy compound, the viscosity is high at the stage of bonding the connection object members, and when the acceleration is applied by impact such as transportation, it is possible to suppress the displacement of the first connection object member and the second connection object member. , In addition, the viscosity of the conductive material can be greatly reduced by using the heat during curing, so that the aggregation of solder particles can be efficiently performed.

In 100% by weight of the above-mentioned conductive material, the content of the above-mentioned thermosetting compound is preferably 20% by weight or more, more preferably 40% by weight or more, still more preferably 50% by weight or more, and preferably 99% by weight or less , more preferably 98% by weight or less, more preferably 90% by weight or less, particularly preferably 80% by weight or less. From the viewpoint of further improving impact resistance, it is preferable that the content of the above-mentioned thermosetting compound is large.

(Thermocuring agent: thermosetting component)

The thermosetting agent thermosets the thermosetting compound. Examples of the thermal curing agent include imidazole curing agents, amine curing agents, phenol curing agents, polythiol curing agents and other mercaptan curing agents, acid anhydrides, thermal cationic initiators (thermal cationic curing agents), and thermal radical generators. agent etc. The above thermosetting agents may be used alone or in combination of two or more.

Since the conductive material can be cured more quickly at a low temperature, an imidazole curing agent, a thiol curing agent, or an amine curing agent is preferable. Moreover, since storage stability improves when a thermosetting compound and the said thermosetting agent are mixed, a latent curing agent is preferable. 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 above-mentioned thermosetting agent may be coated with a polymer substance such as polyurethane resin or polyester resin.

The above-mentioned imidazole curing agent is not particularly limited, and examples thereof 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 adduct, etc.

The polythiol curing agent is not particularly limited, and examples thereof include trimethylolpropane tris-3-mercaptopropionate, pentaerythritol tetrakis-3-mercaptopropionate, and dipentaerythritol hexa-3-mercaptopropionate. .

The amine curing agent is not particularly limited, and examples thereof include hexamethylenediamine, octamethylenediamine, decamethylenediamine, 3,9-bis(3-aminopropyl)-2,4 , 8,10-tetraspiro[5.5]undecane, bis(4-aminocyclohexyl)methane, m-phenylenediamine and diaminodiphenylsulfone, etc.

Examples of the thermal cationic initiator include iodonium-based cationic curing agents (thermal cationic curing agents), oxonium-based cationic curing agents, and sulfonium-based cationic curing agents. Bis(4-tert-butylphenyl)iodonium hexafluorophosphate etc. are mentioned as said iodonium cationic curing agent. Trimethyloxonium tetrafluoroborate etc. are mentioned as said oxonium cationic hardening agent. Examples of the sulfonium-based cationic curing agent include tris-p-tolylsulfonium hexafluorophosphate and the like.

Although it does not specifically limit as said thermal radical generating agent, An azo compound, an organic peroxide, etc. are mentioned. As said azo compound, azobisisobutyronitrile (AIBN) etc. are mentioned. As said organic peroxide, di-t-butyl peroxide, methyl ethyl ketone peroxide, etc. are mentioned.

The reaction initiation temperature of the thermosetting agent is preferably 50°C or higher, more preferably 70°C or higher, more preferably 80°C or higher, and preferably 250°C or lower, more preferably 200°C or lower, and more preferably It is 150°C or lower, particularly preferably 140°C or lower. Solder can be arrange|positioned on an electrode more efficiently as the reaction start temperature of the said thermosetting agent is more than the said minimum and below the said upper limit. The reaction initiation temperature of the thermosetting agent is particularly preferably 80°C or higher and 140°C or lower.

From the viewpoint of more efficiently disposing the solder on the electrodes, the reaction initiation temperature of the thermosetting agent is preferably higher than the melting point of the solder, more preferably 5°C or more, and still more preferably 10°C or more. .

The above-mentioned reaction start temperature of the thermosetting agent means the temperature at which the exothermic peak in DSC starts to rise.

The content of the above-mentioned thermosetting agent is not particularly limited. With respect to 100 parts by weight of the above-mentioned thermosetting compound, the content of the above-mentioned thermosetting agent is preferably 0.01 weight part or more, more preferably 1 weight part or more, and preferably 200 weight parts or less, more preferably 100 weight parts or less, more preferably 75 parts by weight or less. If content of a thermosetting agent is more than the said minimum, it will become easy to fully harden a conductive material. When the content of the thermosetting agent is below the above upper limit, excess thermosetting agent not used for curing after curing is less likely to remain, and the heat resistance of the cured product is further improved.

(Flux)

The above-mentioned conductive material preferably contains a flux. By using a flux, it is possible to arrange the solder on the electrodes more efficiently. In addition, the discovery of the flux effect further reduced the connection resistance between electrodes. The above-mentioned flux is not particularly limited. As the flux, flux generally used for solder bonding and the like can be used. Examples of the above fluxing agent include zinc chloride, mixtures of zinc chloride and inorganic halides, mixtures of zinc chloride and inorganic acids, molten salts, phosphoric acid, derivatives of phosphoric acid, organic halides, hydrazine, organic Acid and turpentine etc. The above-mentioned fluxes may be used alone or in combination of two or more.

Ammonium chloride etc. are mentioned as said molten salt. Lactic acid, citric acid, stearic acid, glutamic acid, glutaric acid, etc. are mentioned as said organic acid. As said rosin, activated rosin, non-activated rosin, etc. are mentioned. The above-mentioned flux is preferably an organic acid containing two or more carboxyl groups, and rosin. The above-mentioned flux may be an organic acid containing two or more carboxyl groups, or rosin. The use of organic acid and rosin having two or more carboxyl groups further improves the conduction reliability between electrodes.

The above-mentioned rosin is a rosin mainly composed of abietic acid. The flux is preferably rosin, more preferably abietic acid. The use of this preferred flux further improves the conduction reliability between electrodes.

The activation temperature (melting point) of the above-mentioned flux is preferably 50°C or higher, more preferably 70°C or higher, more preferably 80°C or higher, and preferably 200°C or lower, more preferably 190°C or lower, still more preferably The preferred temperature is 160°C or lower, more preferably 150°C or lower, even more preferably 140°C or lower. If the activation temperature of the said flux is more than the said minimum and below the said upper limit, the effect of a flux can be exhibited more effectively, and a solder can be arrange|positioned on an electrode more efficiently. The activation temperature (melting point) of the flux is preferably 80°C or higher and 190°C or lower. The activation temperature (melting point) of the above-mentioned flux is particularly preferably 80°C or higher and 140°C or lower.

Examples of the above-mentioned fluxes whose activation temperature (melting point) of the mesh flux is 80°C to 190°C include succinic acid (melting point 186°C), glutaric acid (melting point 96°C), and adipic acid (melting point 152°C). Dicarboxylic acids such as pimelic acid (melting point 104°C), suberic acid (melting point 142°C), benzoic acid (melting point 122°C), malic acid (melting point 130°C), and the like.

In addition, the boiling point of the above-mentioned flux is preferably 200° C. or lower.

From the viewpoint of disposing the solder on the electrodes more efficiently, the melting point of the flux is preferably higher than the melting point of the solder, more preferably 5°C or more, and still more preferably 10°C or more.

From the viewpoint of more efficiently disposing the solder on the electrodes, the melting point of the flux is preferably higher than the reaction initiation temperature of the thermosetting agent, more preferably 5°C or more, and still more preferably 10°C or more. .

The above-mentioned flux may be dispersed in the conductive material, or may be attached to the surface of the conductive particles.

The above-mentioned flux is preferably a flux that releases cations by heating. By using a flux that releases cations by heating, solder can be placed on electrodes more efficiently.

As a flux which releases a cation by the said heating, the said thermal cationic initiator (thermal cationic curing agent) is mentioned.

The content of the flux is preferably not less than 0.5% by weight and preferably not more than 30% by weight, more preferably not more than 25% by weight, based on 100% by weight of the conductive material. The above-mentioned conductive material does not need to contain a flux. When the content of the flux is more than the above-mentioned lower limit and below the above-mentioned upper limit, the oxide film is more difficult to form on the surface of the solder and the electrode, and the oxide film formed on the surface of the solder and the electrode can be removed more effectively.

(filler)

A filler may be added to the above-mentioned conductive material. Fillers can be either organic fillers or inorganic fillers. By adding the filler, it is possible to suppress the distance at which the solder aggregates, and to uniformly aggregate the electroconductive particles over the entire electrode of the substrate.

In 100% by weight of the above-mentioned conductive material, the content of the above-mentioned filler is preferably 0% by weight (not contained) or more, and preferably 5% by weight or less, more preferably 2% by weight or less, and more preferably 1% by weight the following. Solder can be arrange|positioned on an electrode more efficiently as content of the said filler is more than the said minimum and below the said upper limit.

(other ingredients)

The above-mentioned conductive material may, for example, contain fillers, extenders, softeners, plasticizers, polymerization catalysts, curing catalysts, colorants, antioxidants, heat stabilizers, light stabilizers, ultraviolet absorbers, lubricants, Various additives such as antistatic agent and flame retardant.

(Connection structure and method of manufacturing the connection structure)

The connection structure of the present invention includes a first connection object member having at least one first electrode on its surface, a second connection object member having at least one second electrode on its surface, and a connection between the first connection object member and the second connection object. The connection part where the object parts are connected. In the connection structure of this invention, the material of the said connection part is the said conductive material, and the said connection part is formed of the said conductive material. In the connection structure of this invention, the said 1st electrode and the said 2nd electrode are electrically connected by the solder in the said electroconductive particle. In the connection structure of this invention, the said 1st electrode and the said 2nd electrode are electrically connected by the solder part in the said connection part.

The manufacturing method of the connection structure of the present invention includes: using the above-mentioned conductive material, the step of disposing the above-mentioned conductive material on the surface of the first connection object member having at least one first electrode on the surface; On the opposite surface of the target component side, the process of disposing the second connection target component having at least one second electrode on the surface so that the above-mentioned first electrode and the above-mentioned second electrode are opposed; and by heating the above-mentioned conductive material to Above the melting point of the solder in the conductive particles, a connection portion connecting the first connection object member to the second connection object member is formed using the conductive material, and the first electrode and the second connection object member are connected through the solder portion in the connection portion. The process of electrically connecting the above-mentioned second electrodes. It is preferable to heat the said electrically-conductive material to more than the hardening temperature of the said thermosetting compound.

In the connection structure of the present invention and the method of manufacturing the connection structure of the present invention, since a specific conductive material is used, the solder in the conductive particles is easy to gather between the first electrode and the second electrode, and the solder can be efficiently Solder is placed on the electrodes (wires). In addition, part of the solder is less likely to be placed in the region (space) where the electrode is not formed, and the amount of solder placed in the region where the electrode is not 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 electrodes adjacent in the lateral direction that cannot be connected, and to improve insulation reliability.

In addition, in order to efficiently dispose the solder in the conductive particles on the electrodes and considerably reduce the amount of solder disposed in the region where no electrodes are formed, it is preferable to use a conductive paste instead of the conductive film of the above-mentioned conductive material.

The thickness of the solder portion between the electrodes is preferably 10 μm or more, more preferably 20 μm or more, and preferably 100 μm or less, more preferably 80 μm or less. The solder wetting area on the surface of the electrode (the area in contact with the solder out of 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 of manufacturing a connection structure according to the present invention, in the step of arranging the second connection object member and the step of forming the connection portion, it is preferable not to pressurize, but to reduce the weight of the second connection object member In the step of arranging the second connection object member and the step of forming the connection portion applied to the conductive material, it is preferable not to apply a pressure exceeding the weight of the second connection object member to the conductive material. In the above case, the uniformity of the amount of solder in the plurality of solder portions can be further improved. Furthermore, the thickness of the solder portion can be further effectively increased, so that a large amount of solder can easily accumulate between the electrodes, and the solder can be more efficiently arranged on the electrodes (lines). In addition, part of the solder is less likely to be placed in the region (space) where no electrode is formed, and the amount of solder placed in the region where no electrode is formed can be further reduced. Therefore, the conduction reliability between electrodes can be further improved. In addition, it is possible to further prevent electrical connection between electrodes adjacent in the lateral direction that cannot be connected, and further improve insulation reliability.

In addition, if a conductive paste is used instead of a conductive film, it is easy to adjust the thicknesses of the connection part and the solder part according to the coating amount of the conductive paste. On the other hand, the conductive film has a problem that in order to change or adjust the thickness of the connection portion, it is necessary to prepare a conductive film having a different thickness or to prepare a conductive film having a predetermined thickness. In addition, there is a problem in the conductive film that it tends to be difficult to sufficiently lower the melt viscosity of the conductive film 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 equipped with the 1st connection object member 2, the 2nd connection object member 3, and the connection part 4 which connects the 1st connection object member 2 and the 2nd connection object member 3. As shown in FIG. The connection portion 4 is formed of the above-mentioned conductive material. In the present embodiment, the conductive material includes a plurality of conductive particles, a thermosetting compound, and a thermosetting agent. The above-mentioned thermosetting compound and the above-mentioned thermosetting agent are thermosetting components.

The connection part 4 has 4 A of solder parts which gathered and mutually joined the some electroconductive particle, and the hardened|cured material part 4B which heat-hardened the thermosetting component.

The first connection object member 2 has a plurality of first electrodes 2a on the surface (upper surface). The second connection object 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 part 4A. Therefore, the first connection object member 2 and the second connection object member 3 are electrically connected by the solder portion 4A. In addition, in the connection portion 4 , there is no solder in a region (cured product portion 4B portion) different from the solder portion 4A accumulated between the first electrode 2 a and the second electrode 3 a. There is no solder detached from the solder portion 4A in a region (cured product portion 4B portion) different from the solder portion 4A. Moreover, if it is a small amount, solder may exist in the area|region (cured material part 4B part) different from the solder part 4A gathered between the 1st electrode 2a and the 2nd electrode 3a.

As shown in Figure 1, in the connection structure 1, a plurality of conductive particles are accumulated between the first electrode 2a and the second electrode 3a, and after the plurality of conductive particles are melted, the molten material of the conductive particles makes the electrodes The surface is wetted and then solidified to form the solder portion 4A. Therefore, the connection area between 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 electroconductive particles, compared with the case where the outer surface of the electroconductivity is provided on electroconductive particles of metal such as nickel, gold, or copper, the solder portion 4A and the first electrode 2a, and the solder portion 4A and the second The contact area of the electrode 3a becomes larger. Therefore, the conduction reliability and connection reliability in the connection structure 1 are high. In addition, the conductive material may also contain a flux. In the case of using a flux, generally, the flux is gradually inactivated by heating.

Moreover, in the connection structure 1 shown in FIG. 1, the whole of 4 A of solder parts is located in the area|region which opposes between 1st, 2nd electrode 2a, 3a. In the connection structure 1X of the modification shown in FIG. 3, only the connection part 4X is different from the connection structure 1 shown in FIG. The connecting portion 4X has a solder portion 4XA and a cured product portion 4XB. Also like the connection structure 1X, a large number of solder portions 4XA are located in the opposing regions of the first and second electrodes 2a, 3a, and a part of the soldering portion 4XA extends from the opposing regions of the first and second electrodes 2a, 3a. Prominent sideways. The solder portion 4XA protruding laterally from the region where the first and second electrodes 2 a and 3 a face each other is a part of the solder portion 4XA, and is not the solder separated from the solder portion 4XA. In addition, in the present embodiment, the amount of solder detached from the solder portion can be reduced, but the solder detached from the solder portion may exist in the cured product portion.

If the usage-amount of electroconductive particle is reduced, it will become easy to obtain the connection structure 1. When the usage-amount of electroconductive particle increases, it will become easy to obtain connection structure 1X.

From the viewpoint of further improving conduction reliability, in the connection structures 1 and 1X, the first electrode 2a and the second electrode 3a are opposed to each other when viewed along the stacking direction of the first electrode 2a and the connection part 4, 4X and the second electrode 3a. In the case where the first electrode 2a and the second electrode 3a face each other, it is preferable that the solder parts 4A, 4XA in the connection parts 4, 4X are arranged on 50% or more of the 100% area of the area where the first electrode 2a and the second electrode 3a face each other.

From the viewpoint of further improving conduction reliability, when viewing the portion of the first electrode facing the second electrode along the lamination direction of the first electrode, the connection portion, and the second electrode, it is preferable that the 50% or more (more preferably 60% or more, more preferably 70% or more, particularly preferably 80% or more, most preferably 90% or more) is provided with the solder portion in the above connection portion.

From the viewpoint of further improving conduction reliability, when the portion of the first electrode facing the second electrode is viewed in a direction perpendicular to the stacking direction of the first electrode, the connection portion, and the second electrode, Preferably, 70% or more (more preferably 80% or more, more preferably 90% or more, and particularly preferably 95% or more, most preferably 99% or more).

Next, an example of the method of manufacturing the connection structure 1 is demonstrated using the electrically-conductive material which concerns on one Embodiment of this invention.

First, the first connection object member 2 having the first electrode 2a on the surface (upper surface) is prepared. Next, as shown in FIG. 2( a ), conductive material 11 containing thermosetting component 11B and a plurality of conductive particles 11A is arranged on the surface of first connection object member 2 (first step). The conductive material 11 is arranged on the surface of the first connection object member 2 on which the first electrode 2 a is provided. After arrange|positioning the electrically-conductive material 11, 11 A of electroconductive particles are arrange|positioned on both the 1st electrode 2a (line) and the area|region (space) in which the 1st electrode 2a is not formed.

The method of arranging the conductive material 11 is not particularly limited, and examples thereof include coating with a dispenser, screen printing, and spray coating with an inkjet device.

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. 2( b), among the conductive materials 11 on the surface of the first connection object member 2, the first connection object member 2 is disposed on the surface of the conductive material 11 on the side opposite to the first connection object member 2 side. 2. Connection object part 3 (second process). On the surface of the conductive material 11, the second connection object member 3 is arranged from the second electrode 3a side. At this time, the 1st electrode 2a and the 2nd electrode 3a are made to oppose.

Next, the conductive material 11 is heated more than the melting point of 11 A of electroconductive particles (3rd process). It is preferable to heat the conductive material 11 to a temperature equal to or higher than the curing temperature of the thermosetting component 11B (adhesive). During this heating, 11 A of electroconductive particles which exist in the region where an electrode is not formed gather between the 1st electrode 2a and the 2nd electrode 3a (self-aggregation effect). In this embodiment, since a conductive material is used instead of a conductive film, and since a conductive material has a specific composition, 11 A of electroconductive particles gather efficiently between the 1st electrode 2a and the 2nd electrode 3a. Moreover, 11 A of electroconductive particles fuse|melt and join mutually. In addition, the thermosetting component 11B is thermally cured. As a result, as shown in FIG.2(c), the connection part 4 which connects the 1st connection object member 2 and the 2nd connection object member 3 is formed using the electrically-conductive material 11. As shown in FIG. The connection part 4 is formed with the conductive material 11, the solder part 4A is formed by bonding of several electroconductive particle 11A, and the hardened part 4B is formed by thermosetting of the thermosetting component 11B. If the conductive particle 11A moves sufficiently, after the movement of the conductive particle 11A not located between the first electrode 2a and the second electrode 3a starts, until the movement of the conductive particle 11A to the first electrode 2a and the second electrode 3a Between 3a, it is not necessary to keep the temperature constant.

In this embodiment, it is preferable not to pressurize in the said 2nd process and the said 3rd process. At this time, the weight of the second connection object member 3 is applied to the conductive material 11 . Therefore, when forming the connection part 4, 11 A of electroconductive particles gather efficiently between the 1st electrode 2a and the 2nd electrode 3a. Moreover, when pressurization is performed in at least one of the said 2nd process and the said 3rd process, the tendency to inhibit the action|action which electroconductive particle gathers between a 1st electrode and a 2nd electrode becomes high.

However, if the distance between the first electrode and the second electrode can be ensured, pressurization may be performed. As a means of securing the space between electrodes, for example, it is sufficient to add a spacer corresponding to a desired space between electrodes, and to arrange at least one spacer, preferably three or more spacers, between electrodes. Examples of the separator include inorganic particles and organic particles. The spacers are preferably insulating particles.

In addition, in this embodiment, since no pressure is applied, when the second connection object member is superimposed on the first connection object member coated with a conductive material, even if the electrodes of the first connection object member and the second In the state where the alignment of the electrodes of the connection object components deviates, and the first connection object component is overlapped with the second connection object component, the deviation can also be corrected, so that the electrodes of the first connection object components are connected to the second connection object. Electrode connection of object parts (self-orientation effect). This is because, among the molten solder self-agglomerated between the electrode of the first connection object member and the electrode of the second connection object member, the solder between the electrode of the first connection object member and the electrode of the second connection object member The energy of the smallest area in contact with other components of the conductive material is stable, so the force that adjusts the connection structure with the smallest area, that is, the connection structure that is aligned, acts. At this time, it is desirable that the conductive material is not cured and that the viscosity of components other than the conductive particles of the conductive material is sufficiently low at the temperature and time.

In this way, the connection structure 1 shown in FIG. 1 is obtained. In addition, the said 2nd process and the said 3rd process may be performed continuously. Moreover, after performing the said 2nd process, you may move the obtained laminated body of the 1st connection object member 2, the conductive material 11, and the 2nd connection object member 3 to a heating part, and may perform the said 3rd process. In order to perform the above-mentioned heating, the above-mentioned laminated body may be arranged on a heating member, or the above-mentioned laminated body may be arranged in a space to be heated.

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

In addition, after the above-mentioned third step, the first connection object member or the second connection object member can be peeled off from the connection portion for the purpose of position correction and manufacturing rework. The heating temperature for this peeling is preferably at least the melting point of the electroconductive particles, more preferably at least the melting point (°C) of the electroconductive particles+10°C. The heating temperature for this peeling may be the melting point (degreeC)+100 degreeC or less of electroconductive particle.

As the heating method in the above-mentioned third step, there may be mentioned a method of heating the entire connection structure using a reflow furnace or an oven at a temperature above the melting point of the conductive particles and above the solidification temperature of the thermosetting component, or heating and connecting only locally. The method of the connection part of the structure.

Examples of an instrument used in the method of local heating include a hot plate, a heat gun for applying hot air, a soldering iron, an infrared heater, and the like.

In addition, when local heating is performed with a heating plate, it is preferable to form the upper surface of the heating plate by using a metal with high thermal conductivity directly below the connecting portion, and forming other parts that are not preferably heated by a material with low thermal conductivity such as fluororesin. .

The above-mentioned first and second connection object members are not particularly limited. Specific examples of the first and second connection target members include semiconductor chips, semiconductor packages, LED chips, LED packages, electronic components such as capacitors and diodes, resin films, printed circuit boards, flexible printed circuit boards, flexible Electronic components such as flexible flat cables, rigid-flex substrates, glass epoxy substrates, and circuit substrates such as glass substrates. It is preferable that the said 1st, 2nd connection object components are electronic components.

At least one of the first connection object member and the second connection object member is preferably a resin film, a flexible printed circuit board, a flexible flat cable, or a rigid-flex substrate. The above-mentioned second connection object member is preferably a resin film, a flexible printed circuit board, a flexible flat cable, or a rigid-flex substrate. Resin films, flexible printed circuit boards, flexible flat cables, and rigid-flex substrates are highly flexible and relatively lightweight. When using a conductive film for the connection of such a connection object member, it exists in the tendency which electroconductive particle becomes difficult 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-flex substrate is used, conductive particles can be efficiently gathered on the electrode, and thus the electrode can be sufficiently improved. conduction reliability between. When using resin films, flexible printed circuit boards, flexible flat cables, or rigid-flex substrates, the conduction between electrodes that are not pressurized is more reliable than when using other connection target parts such as semiconductor chips The performance improvement effect can be further improved.

Metal electrodes such as gold electrodes, nickel electrodes, tin electrodes, aluminum electrodes, copper electrodes, molybdenum electrodes, silver electrodes, SUS electrodes, and tungsten electrodes are exemplified as electrodes provided on the member to be connected. When the said connection object member is a flexible printed circuit board, it is preferable that the said electrode is a gold electrode, a nickel electrode, a tin electrode, a silver electrode, or a copper electrode. When the said connection object member is a glass substrate, it is preferable that the said electrode is an aluminum electrode, a copper electrode, a molybdenum electrode, a silver electrode, or a tungsten electrode. In addition, when the above-mentioned electrode is an aluminum electrode, it may be an electrode formed only of aluminum, or may be an electrode in which an aluminum layer is laminated on the surface of the metal oxide layer. Examples of the material of the metal oxide layer include indium oxide doped with a trivalent metal element, zinc oxide doped with a trivalent metal element, and the like. As said trivalent metal element, Sn, Al, Ga, etc. are mentioned.

Hereinafter, an Example and a comparative example are given, and this invention is demonstrated concretely. The present invention is not limited only to the following examples.

Thermosetting compound 1: 2,4-bis(glycidyloxy)benzophenone (a crystalline thermosetting compound, melting point: 94°C, molecular weight: 362)

Synthesis of 2,4-bis(glycidyloxy)benzophenone:

27 g of 2,4-dihydroxybenzophenone, 230 g of epichlorohydrin, 70 g of n-butanol, and 1 g of tetraethylbenzyl ammonium chloride were put into a 3-necked flask, and stirred at room temperature to dissolve. Then, under a nitrogen atmosphere, the temperature was raised to 70° C. with stirring, and 45 g of an aqueous sodium hydroxide solution (concentration: 48% by weight) was added dropwise under reflux under reduced pressure. Dropwise addition was performed over 4 hours. Then, the reaction was carried out at 70° C. for 2 hours while removing moisture using a Dean-Stark tube. Then, under reduced pressure, unreacted epichlorohydrin was removed.

The obtained reaction product was dissolved in MEK (methyl ethyl ketone):n-butanol=3:1 (weight ratio) in the mixed solvent 400g, added sodium hydroxide aqueous solution (concentration 10% by weight) 5g, and in 80 °C for 2 hours.

Thereafter, it was cooled to room temperature, and washed with pure water until the washing liquid became neutral. The organic layer was fractionated while being filtered, and the residual water and mixed solvent were removed under reduced pressure to obtain a reaction product.

Using n-hexane, 34 g of the above-mentioned reaction product was purified by recrystallization, and residual solvent components were removed by vacuum drying.

The epoxy compound obtained had a melting point of 94° C. by DSC, an epoxy equivalent of 176 g/eq., a molecular weight of 362 obtained by mass spectrometry, and a melt viscosity of 5 mPa·s at 150° C.

・Differential Scanning Calorimetry (DSC) measurement device and measurement conditions

Apparatus: "X-DSC7000" manufactured by Hitachi-hightech Co., Ltd., sample amount: 3 mg, temperature condition: 10°C/min

Melt viscosity at 150°C: and ASTM D4287, measured using an ICI cone-plate viscometer manufactured by M.S.T.Engineering Co., Ltd.

· Determination of epoxy equivalent: based on JIS K7236: 2001

・Measurement of molecular weight: Measured using a mass spectrometer GC-MS device ("JMSK-9" manufactured by JEOL Ltd.)

Thermosetting compound 2: 4,4'-bis(glycidyloxy)benzophenone (crystalline thermosetting compound, melting point: 132°C, molecular weight: 362)

Synthesis of 4,4'-bis(glycidyloxy)benzophenone:

27 g of 4,4'-dihydroxybenzophenone, 230 g of epichlorohydrin, 70 g of n-butanol, and 1 g of tetraethylbenzyl ammonium chloride were put into a 3-necked flask, and stirred at room temperature to dissolve. Then, under a nitrogen atmosphere, the temperature was raised to 70° C. with stirring, and 45 g of an aqueous sodium hydroxide solution (concentration: 48% by weight) was added dropwise under reflux under reduced pressure. Dropwise addition was performed over 4 hours. Then, the reaction was carried out at 70° C. for 2 hours while removing moisture using a Dean-Stark tube. Then, unreacted epichlorohydrin was removed under reduced pressure.

The obtained reaction product was dissolved in 400 g of a mixed solvent of MEK (methyl ethyl ketone):n-butanol=3:1 (weight ratio), 5 g of aqueous sodium hydroxide solution (concentration 10% by weight) was added, and the mixture was heated at 80° C. Heat for 2 hours.

Thereafter, it was cooled to room temperature, and washed with pure water until the washing liquid became neutral. The organic layer was fractionated while filtering, and the residual water and mixed solvent were removed under reduced pressure to obtain a reaction product.

Using n-hexane, 34 g of the above-mentioned reaction product was purified by recrystallization, and residual solvent components were removed by vacuum drying.

The epoxy compound obtained had a melting point of 132° C. by DSC, an epoxy equivalent of 176 g/eq., a molecular weight of 362 obtained by mass spectrometry, and a melt viscosity of 12 mPa·s at 150° C.

Thermosetting compound 3: Epoxy group-containing acrylic polymer, "MARPROOFG-0150M" manufactured by NOF Corporation

Thermosetting agent 1: Pentaerythritol tetrakis (3-mercaptobutyrate), "CURRANTSMTPE1" manufactured by Showa Denko Co., Ltd.

Latent epoxy thermosetting agent 1: "Fujicure 7000" manufactured by T&KT0KA Co., Ltd.

Flux 1: glutaric acid, manufactured by Wako Pure Chemical Industries, Ltd., melting point (activation temperature) 152°C

The preparation method of solder particles 1-2:

Solder particle 1:

Add 200 g of SnBi solder particles ("DS-10" manufactured by Mitsui Kinzoku Co., Ltd., average particle diameter (median particle diameter) 12 μm) and a silane coupling agent ("KBM-903" manufactured by Shin-Etsu Chemical Co., Ltd., 10 g of 3-aminopropyltrimethoxysilane), 120 g of toluene, and 1 g of water were reacted for 3 hours using a Dean-Stark apparatus under a nitrogen atmosphere of 80° C. The silanol group of the methoxy group and the Sn—OH on the surface of the solder particle are dehydrated and condensed.

Thereafter, solder particles were recovered by a 10 μm CMF filter, and sufficiently washed with acetone.

The solder particles were transferred to a three-neck flask, 200 g of acetone and 40 g of anhydrous glutaric acid were put in, and the 3-aminopropyltrimethoxy The amino group of the silane reacts with the carboxyl group derived from the anhydrous glutaric acid. Thereafter, solder particles were recovered by a 10 μm CMF filter, and sufficiently washed with acetone.

Using a sieve, topping (removal of coarse particles) was carried out at the top 20 μm to obtain solder particles with an average particle diameter of 12 μm, a CV value of 20%, and the other carboxyl group derived from glutaric acid anhydrate on the surface. 1.

Solder particle 2:

Except changing 3-aminopropyltrimethoxysilane to silane coupling agent (Shin-Etsu Chemical Co., Ltd. "KBM-603", N-2-(aminoethyl)-3-aminopropyltrimethoxysilane) In the same manner, solder particles 2 were obtained. The average particle diameter was 12 μm, and the CV value was 20%.

Solder particles A: SnBi solder particles (“DS-10” manufactured by Mitsui Kinzoku Co., Ltd., average particle size (median particle size) 12 μm)

(CV value of solder particles)

The CV value was measured with a laser diffraction particle size distribution analyzer (“LA-920” manufactured by Horiba, Ltd.).

(Examples 1 to 6 and Comparative Example 1)

The components shown in the following Table 1 were mixed in the compounding quantity shown in the following Table 1, and the anisotropic conductive paste was obtained.

(1) Fabrication of the first connection structure (L/S=50μm/50μm)

(Condition A)

Using the anisotropic conductive paste just produced, the 1st, 2nd, and 3rd connection structures were produced as follows.

(Condition B)

And the 1st, 2nd, and 3rd connection structures were produced as follows using the anisotropic conductive paste just produced. At this time, on the upper surface of the glass epoxy substrate, the anisotropic conductive paste just produced was applied by screen printing using a metal mask so that the electrode on the glass epoxy substrate had a thickness of 100 μm. An anisotropic conductive paste layer was formed, and then, after standing at 23° C. and 50% RH for 10 hours in an air environment, a flexible printed substrate was placed on the upper surface of the anisotropic conductive paste layer so that the electrodes faced each other. layered in a manner. Other than that, it was made the same as condition A. The paste (anisotropic conductive paste layer) left to stand was recovered and the viscosity was measured.

(Concrete production method of connection structure)

A glass epoxy substrate (FR-4 substrate) (first connection target member) having a copper electrode pattern (thickness of copper electrode: 12 μm) having an L/S of 50 μm/50 μm and an electrode length of 3 mm on the upper surface was prepared. Separately, a flexible printed circuit board (second connection object member) having a copper electrode pattern (thickness of copper electrode: 12 μm) having an L/S of 50 μm/50 μm and an electrode length of 3 mm on the lower surface was prepared.

The overlapping area of the glass epoxy substrate and the flexible printed substrate is set to 1.5cm×3mm, and the number of connected electrodes is set to 75 pairs.

On the upper surface of the above-mentioned glass epoxy substrate, the anisotropic conductive paste just produced was applied by screen printing using a metal mask in such a manner that the electrode of the glass epoxy substrate had a thickness of 100 μm, and each Anisotropic conductive paste layer. Next, the above-mentioned flexible printed circuit board was laminated|stacked on the upper surface of an anisotropic conductive paste layer so that electrodes may oppose each other. At this time, pressurization was not performed. The above-mentioned weight of the flexible printed circuit board was applied to the anisotropic conductive paste layer. After that, while heating so that the temperature of the anisotropic conductive paste layer would be 190° C., while melting the solder, the anisotropic conductive paste layer was cured at 190° C. for 10 seconds to obtain a first connection structure.

(2) Fabrication of the second connection structure (L/S=75μm/75μm)

A glass epoxy substrate (FR-4 substrate) (first connection target member) having an L/S of 75 μm/75 μm and a copper electrode pattern (thickness of copper electrode: 12 μm) having an electrode length of 3 mm on the upper surface was prepared. Separately, a flexible printed circuit board (second connection object member) having a copper electrode pattern (thickness of copper electrode: 12 μm) having an L/S of 75 μm/75 μm and an electrode length of 3 mm was prepared on the lower surface.

Except having used the said glass epoxy board|substrate and flexible printed circuit board which differ in L/S, it carried out similarly to preparation of the 1st connection structure, and obtained the 2nd connection structure.

(3) Fabrication of the third connection structure (L/S=100μm/100μm)

A glass epoxy substrate (FR-4 substrate) (first connection target member) having a copper electrode pattern (copper electrode thickness 12 μm) with an L/S of 100 μm/100 μm and an electrode length of 3 mm on the upper surface was prepared. Separately, a flexible printed circuit board (second connection object member) having a copper electrode pattern (thickness of copper electrode: 12 μm) having an L/S of 100 μm/100 μm and an electrode length of 3 mm on the lower surface was prepared.

Except having used the said glass epoxy board|substrate and flexible printed circuit board which differ in L/S, it carried out similarly to preparation of the 1st connection structure, and obtained the 3rd connection structure.

(Evaluation)

(1) Viscosity

The viscosity (η25) of the anisotropic conductive paste at 25° C. was measured on conditions of 25° C. and 5 rpm using an E-type viscometer (“TVE22L” manufactured by Toki Sangyo Co., Ltd.).

(2) Thickness of solder part

The thickness of the solder part located between the upper and lower electrodes was evaluated by observing the cross-section of the obtained 1st connection structure.

(3) Arrangement accuracy of solder on electrodes 1

In the obtained first, second, and third connection structures, when the portion facing the first electrode and the second electrode is observed along the stacking direction of the first electrode, the connection portion, and the second electrode, the first The ratio X of the area where the solder portion in the connection portion is arranged in the area 100% of the portion where the electrode and the second electrode are opposed was evaluated. The placement accuracy 1 of the solder on the electrodes was judged according to the following criteria.

[Criteria for the placement accuracy 1 of the solder on the electrode]

○○: Ratio X is 70% or more

○: Ratio X is 60% or more and less than 70%

Δ: Proportion X is 50% or more and less than 60%

×: Proportion X is less than 50%

(4) Arrangement accuracy of solder on electrodes 2

In the obtained first, second, and third connection structures, the portion facing the first electrode and the second electrode was observed along the direction perpendicular to the stacking direction of the first electrode, the connection portion, and the second electrode , the ratio Y of the solder portion arranged in the connection portion of the portion where the first electrode and the second electrode face each other out of 100% of the solder portion in the connection portion was evaluated. The placement accuracy 2 of the solder on the electrodes was judged according to the following criteria.

[Criteria for the placement accuracy 2 of the solder on the electrode]

○○: Ratio Y is 99% or more

○: Ratio Y is 90% or more and less than 99%

△: Proportion Y is 70% or more and less than 90%

×: Proportion Y is less than 70%

(5) Conduction reliability between upper and lower electrodes

In the obtained first, second, and third connection structures (n=15 pieces), the connection resistance for each connection position between the upper and lower electrodes was measured by the four-terminal method. Calculate the average value of the connection resistance. In addition, the connection resistance can be obtained by measuring the voltage when a constant current flows from the relationship of voltage=current×resistance. Conduction reliability was judged according to the following criteria.

[Judgement criteria for conduction reliability]

○○: The average value of connection resistance is 50mΩ or less

○: The average value of the connection resistance exceeds 50mΩ and is less than 70mΩ

△: The average value of the connection resistance exceeds 70mΩ and is less than 100mΩ

×: The average value of connection resistance exceeds 100mΩ or poor connection occurs

(6) Insulation reliability between electrodes adjacent in the lateral direction

In the obtained first, second, and third connection structures (n=15), after standing for 100 hours in an environment at 85°C and a humidity of 85%, 5V was applied between laterally adjacent electrodes, and at 25 positions The resistance value was measured. Insulation reliability was judged by the following criteria.

[Criteria for judging insulation reliability]

○○: The average value of connection resistance is 107Ω or more

○: The average value of the connection resistance is 106Ω or more and less than 107Ω

△: The average value of connection resistance is more than 105Ω and less than 106Ω

×: The average value of connection resistance is less than 105Ω

(7) Position shift between upper and lower electrodes

In the obtained first, second, and third connection structures, when the portion facing the first electrode and the second electrode is observed along the stacking direction of the first electrode, the connection portion, and the second electrode, the first electrode Whether the centerline of the electrode is aligned with the centerline of the second electrode and the distance of the position deviation are evaluated. The positional displacement between the upper and lower electrodes was determined according to the following criteria.

[Criteria for judging the displacement between the upper and lower electrodes]

○○: position deviation is less than 15μm

○: Position shift is 15 μm or more and less than 25 μm

△: The position deviation is more than 25 μm and less than 40 μm

×: Position shift is 40 μm or more

The results are shown in Table 1 below.

Table 1

Not only flexible printed circuit boards but also resin films, flexible flat cables, and rigid-flex substrates show the same tendency.

Explanation of reference signs

1. 1X... connection structure

2...The first connection target part

2a...first electrode

3...The second connection target part

3a...second electrode

4. 4X... connection part

4A, 4XA...Solder part

4B, 4XB...cured part

11…conductive material

11A…conductive particles

11B...Heat-curing components

21...Conductive particles (solder particles)

31...Conductive particles

32... Substrate particles

33...Conductive part (conductive part with solder)

33A...Second conductive part

33B...Solder part

41...conductive particles

42...Solder part

Claims (9)

1. a kind of conductive material, comprising multiple electroconductive particles, Thermocurable compound and thermal curing agents,

The electroconductive particle has solder in the outer surface part of conductive part,

The electroconductive particle has O-Si keys in the outer surface of the solder of the conductive part.

2. conductive material according to claim 1, wherein,

The electroconductive particle has Sn-O-Si keys in the outer surface of the solder of the conductive part.

3. conductive material according to claim 1 or 2, wherein,

The electroconductive particle is the surface treatment based on silane coupler.

4. conductive material according to any one of claim 1 to 3, wherein,

The electroconductive particle has amino in the outer surface of the solder of the conductive part.

5. conductive material according to any one of claim 1 to 4, wherein,

The electroconductive particle has in the outer surface of the solder of the conductive part via Sn-O-Si keys wraps carboxylic Group.

6. conductive material according to any one of claim 1 to 5, wherein,

The electroconductive particle is semiconductor particles.

7. conductive material according to any one of claim 1 to 6, wherein,

The average grain diameter of the electroconductive particle is more than 1 μm and less than 60 μm.

8. conductive material according to any one of claim 1 to 7, wherein,

In the weight % of conductive material 100, the content of the electroconductive particle is more than 10 weight % and below 80 weight %.

9. a kind of connecting structure body, possesses：

First connecting object part, it has first electrode on surface；

Second connecting object part, it has second electrode on surface；

Connecting portion, the first connecting object part is connected by it with the second connecting object part,

The material of the connecting portion is the conductive material any one of claim 1 to 8,

The first electrode utilizes the solder in the electroconductive particle to electrically connect with the second electrode.