JP2009277652A - Circuit connection material and connection structure for circuit member - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a circuit connection material and a connection structure for a circuit member capable of reducing connection resistance between circuit electrodes arranged to face each other and reducing possibility that adjacent circuit electrodes are conducted and short-circuited. <P>SOLUTION: The circuit connection material 12 includes an adhesive composition, a first particle 6, and a second particle 8. The first particle 6 includes a core 2 made of metal with a low-melting point as a principal component, and an insulating layer 4 covering the surface of the core 2 and made of a resin composition with a softening point lower than a melting point of the metal with the low melting point. The second particle 8 includes a smaller average particle diameter rather than that of the core 2, and is made of a material with a melting point or a softening point higher than the melting point of the metal with the low melting point as a principal component. The insulating layer 4 of the first particle 6 is partially removed since the insulating layer 4 is softened, and conduction between the circuit electrodes is attempted by making metal connection between the core 2 exposed from the insulating layer 4 and the circuit electrode. The second particle 8 is functioned under a connection condition as a spacer. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a circuit connection material comprising conductive particles in an adhesive composition, and a circuit member connection structure using the circuit connection material.

  With the downsizing and thinning of electronic parts, circuit electrodes of circuit members used for electronic parts are becoming higher in density and higher in definition. An anisotropic conductive adhesive or an anisotropic conductive film is used as a circuit connection material for connecting the first circuit member and the second circuit member. For example, the anisotropic conductive film is formed by forming a circuit connection material made of a plurality of conductive particles (for example, metal particles such as Ni) and an adhesive composition into a film shape.

  The first circuit member and the second circuit member are connected by the following method. First, in a state where the first circuit electrode of the first circuit member and the second circuit electrode of the second circuit member are arranged to face each other, there is a difference between the first circuit member and the second circuit member. A conductive film is interposed. Thereafter, the structure composed of the first and second circuit members and the anisotropic conductive film is heated and pressurized in a predetermined direction. In this case, when the anisotropic conductive film is cured, the first circuit member is bonded and fixed to the second circuit member. Further, the first circuit electrode and the second circuit electrode that are arranged to face each other are electrically connected, and the adjacent first and second circuit electrodes are electrically insulated from each other.

  In the above method, the conduction between the first circuit electrode and the second circuit electrode that are arranged to face each other is mainly caused by the conductive particles in the anisotropic conductive film coming into contact with the first and second circuit electrodes. can get. However, if the rigidity of the conductive particles is high, the contact area between the conductive particles and the first and second circuit electrodes and the contact area between the conductive particles cannot be sufficiently increased.

  Thus, as an attempt to increase the contact area, for example, a method using conductive particles in which the outermost layer made of a low melting point metal such as solder covers the surface of the polymer core is disclosed (for example, see Patent Documents 1 to 3). . In this case, the conductive particles are melted by heating, and the melted low melting point metal is metal-bonded to the first and second circuit electrodes, so that the gap between the first circuit electrode and the second circuit electrode arranged opposite to each other is obtained. The connection resistance can be lowered.

JP-A-7-157720 JP 2002-170427 A Japanese Patent No. 3542611

  However, in Patent Documents 1 to 3, the connection resistance between the first circuit electrode and the second circuit electrode arranged opposite to each other is still high, and it is strongly desired to further reduce this connection resistance. Therefore, in order to further reduce the connection resistance, the present inventors have examined the use of conductive particles made of only a low-melting-point metal without a nucleus as disclosed in Patent Documents 1 to 3.

  However, when such conductive particles are heated and pressurized in a predetermined direction, the conductive particles are melted when the temperature of the conductive particles reaches the melting point of the low melting point metal, and the molten conductive particles become the first and second circuits. It will be crushed by the member. Moreover, since the surface tension of the molten low melting point metal is very high, adjacent molten conductive particles are fused and joined together in a direction orthogonal to the pressing direction. As a result, the adjacent first and second circuit electrodes become conductive and short-circuited. In particular, when the pitch between the adjacent first and second circuit electrodes is narrow, the above problem becomes significant.

  Therefore, the present invention reduces the connection resistance between the first circuit electrode and the second circuit electrode that are arranged opposite to each other, and conducts a short circuit between the adjacent first and second circuit electrodes. It is an object of the present invention to provide a circuit connection material and a circuit member connection structure that can reduce the possibility of occurrence of the above.

  The circuit connection material of the present invention is a circuit connection material for connecting the first circuit electrode and the second circuit electrode sandwiched between the first circuit electrode and the second circuit electrode facing each other. An adhesive composition having fluidity by heating, first particles, and second particles, wherein the first particles are mainly composed of a low melting point metal having a melting point of 130 to 250 ° C. And an insulating layer made of a resin composition that covers the surface of the core and has a softening point lower than the melting point of the low-melting-point metal. The main component is a material having a small particle size, a melting point higher than the melting point of the low melting point metal or a softening point, and the first particles are connected to the first circuit electrode and the second circuit electrode. The insulating layer was softened and partially removed by heating and pressurization during circuit connection, and was exposed from the insulating layer And the first and second circuit electrodes are metal-bonded to each other to achieve conduction between the first circuit electrode and the second circuit electrode, and the second particles are connected to the first circuit electrode and the second circuit electrode. When connected to the circuit electrode, it functions as a spacer under the connection conditions of the first and second circuit electrodes.

  When the first particles and the second particles included in the circuit connection material are sandwiched between the circuit electrodes facing each other, first, the insulating layer of the first particles is softened at the softening point of the resin composition. In addition, by being pressed by the first circuit electrode and the second circuit electrode, a part of the insulating layer is selectively removed at the pressed portion of the first particles, and the core is exposed from the insulating layer. Then, when further heated, the core melts at the melting point of the low melting point metal. As a result, the first and second circuit electrodes and the molten core are metal-bonded. Here, the circuit connecting material includes the second particles, and the second particles have a melting point or a difficulty point higher than that of the low-melting point metal and have a particle size smaller than that of the core. The melted core is less likely to be crushed by the first and second circuit electrodes. Therefore, it is avoided that the first particles are crushed excessively, and the melted cores can be prevented from joining in the direction orthogonal to the pressing direction. Furthermore, since portions other than the above-described exposed portions on the surface of the core are covered with the insulating layer, it is possible to further suppress the fusion of the melted cores in the direction orthogonal to the pressing direction. Further, since the core is covered with the insulating layer, the core is hardly oxidized. Therefore, when the first and second particles are heated and pressed in a predetermined direction, the conductivity in the pressing direction is improved.

  In the circuit connection material of the present invention, the content ratio of the first particles with respect to the total mass is 1 to 10 mass%, and the content ratio of the second particles with respect to the total mass is 1 to 10 mass%. It is good.

  Moreover, the circuit connection material of this invention may be formed in a film form. By forming the circuit connection material in a film like this, problems such as tearing, cracking, and stickiness of the circuit connection material hardly occur, and handling of the circuit connection material becomes easy.

  The circuit member connection structure of the present invention comprises any one of the above circuit connection materials, a first circuit electrode, and a second circuit electrode, wherein the first circuit electrode and the second circuit electrode are: They are electrically connected to each other through a circuit connecting material.

  In this circuit member connection structure, since the circuit electrodes are connected to each other by the circuit connection material, the connection resistance between the facing circuit electrodes is reduced, and the possibility of a short circuit between adjacent circuit electrodes is reduced. .

  According to the present invention, the connection resistance between the first circuit electrode and the second circuit electrode that are arranged to face each other is reduced, and the adjacent first and second circuit electrodes are electrically connected to each other and short-circuited (short-circuited). It is possible to provide a circuit connection material and a circuit member connection structure that can reduce the possibility of occurrence of the above.

It is sectional drawing which shows typically the circuit connection material which concerns on 1st Embodiment of this invention. It is sectional drawing which shows a film-form circuit connection material typically. It is sectional drawing which shows typically the connection structure of the circuit member which concerns on embodiment of this invention. (A)-(c) is sectional drawing which shows typically each process of the manufacturing method of the connection structure of the circuit member of FIG. It is sectional drawing which shows typically the connection structure of the circuit electrode which concerns on 2nd Embodiment of this invention.

  Hereinafter, embodiments of a circuit connection material and a circuit member connection method of the present invention will be described in detail with reference to the accompanying drawings. In the description of the drawings, the same reference numerals are used for the same or equivalent elements, and duplicate descriptions are omitted. In the following description, (meth) acrylate means acrylate or a corresponding methacrylate.

[First Embodiment]
The circuit connection material 1 according to the first embodiment of the present invention includes an adhesive composition and a particle mixture 10 shown in FIG. The particle mixture 10 includes two types of particles, the first particle 6 and the second particle 8. Specifically, the circuit connection material 1 is obtained by dispersing two types of particles, that is, first particles 6 and second particles 8 in an adhesive composition. As will be described in detail later, this circuit connecting material 1 is used mainly in the state of being formed in a film shape, and is formed between the first circuit electrode and the second circuit electrode that are heated and pressed opposite to each other. Is a circuit connection material for connecting the first and second circuit electrodes. In such an electrode connection structure, the first particles 6 and the second particles 8 are sandwiched between the first circuit electrode and the second circuit electrode.

(Particle mixture)
As shown in FIG. 1, the particle mixture 10 includes first particles 6 and second particles 8. The first particles 6 include a core 2 mainly composed of a low melting point metal and an insulating layer 4 that covers the surface 2 a of the core 2. The insulating layer 4 is made of a resin composition having a softening point lower than the melting point of the low melting point metal constituting the core 2. The second particles 8 are mainly composed of a material having a melting point or a softening point higher than that of the low melting point metal. The shape of the 1st particle 6 and the 2nd particle 8 is not specifically limited, For example, it is a substantially spherical shape.

  Here, “softening point” refers to Vicat softening temperature or glass transition temperature. Vicat softening temperature is achieved by placing a test piece of the specified dimensions in the heating bath, raising the temperature of the bath with the end face of a certain cross-sectional area pressed against the center, and the end face to the test piece to a certain depth. It is the temperature at the time of biting (JIS K7206). The glass transition temperature is a peak temperature of loss tangent (tan δ) measured by dynamic viscoelasticity measurement.

  When this circuit connection material 1 connects the first and second circuit electrodes facing each other, the second particles 8 function as spacers provided between the first and second circuit electrodes.

  The circuit connecting material 1 containing the particle mixture 10 is heated and pressurized in a predetermined direction through the first and second circuit electrodes when the first and second circuit electrodes are connected. Thereby, first, at the softening point of the resin composition, the insulating layer 4 of the first particles 6 is softened and pressed by the first and second circuit electrodes, whereby the first particles 6 are pressed. Part of the insulating layer 4 is selectively removed at the portion, and the core 2 is exposed from the insulating layer 4. Further heating thereafter causes the core 2 to melt at the melting point of the low melting point metal. As a result, the first and second circuit electrodes and the molten core are metal-bonded.

  Since the particle mixture 10 includes the second particles 8, the molten core is less likely to be crushed by the first and second circuit electrodes. Therefore, it can suppress that the fuse | melted cores join in the direction orthogonal to a pressurization direction. Furthermore, since the portions other than the above-described exposed portions on the surface 2a of the core 2 are covered with the insulating layer 4, it is possible to prevent the molten cores from being joined to each other in the direction orthogonal to the pressing direction. Therefore, in the particle mixture 10 of the present embodiment, the conductivity in the pressurizing direction is improved and the insulation in the direction orthogonal to the pressurizing direction is improved during heating and pressurization in a predetermined direction.

  Moreover, in the particle mixture 10 of this embodiment, since the core 2 is coat | covered with the insulating layer 4, the core 2 is hard to oxidize. Therefore, when the particle mixture 10 is heated and pressurized in a predetermined direction, conductivity in the pressing direction is improved.

(First particle)
As the low melting point metal constituting the core 2 of the first particle 6, for example, various eutectic alloys, non-eutectic low melting point alloys or single metals can be used. For example, Pb82.6-Cd17.4 (melting point 248 ° C), Pb85-Au15 (melting point 215 ° C), Bi97-Na3 (melting point 218 ° C), Bi57-Sn43 (melting point 139 ° C), Sn (melting point 232 ° C), In97 .2-Zn 2.8 (melting point 144 ° C.), In (melting point 157 ° C.) and the like.

  The melting point of the low melting point metal forming the core 2 is preferably 130 ° C to 250 ° C, more preferably 150 to 200 ° C. In this case, the temperature when heating the particle mixture 10 may be low. Therefore, when the particle mixture 10 is heated together with another member such as the circuit electrode, for example, the thermal influence on the other member can be reduced.

  The average particle diameter of the core 2 is preferably 1 to 10 μm. When the average particle diameter of the core 2 particles is 1 μm or more, the melted core becomes more difficult to be crushed, so that the melted cores tend to be suppressed from being joined in the direction orthogonal to the pressing direction. is there. On the other hand, when the average particle size of the particles of the core 2 is 10 μm or less, for example, it is possible to suppress a decrease in the bonding area or contact area between the molten core and the circuit electrode. Therefore, by making the average particle diameter of the particles of the core 2 1 to 10 μm, it is possible to prevent the melted cores from being joined to each other in the direction orthogonal to the pressing direction, and to join the melted core and the circuit electrode. The area or contact area can be increased.

  The insulating layer 4 is not particularly limited as long as it is made of a resin composition having a softening point lower than the melting point of the low melting point metal constituting the core 2, but a resin composition containing a thermoplastic resin or a hot melt resin. Preferably it consists of. Also useful are base polymers or elastomers of hot melt adhesives having heat softening or melting points. Examples of such resins include polyethylene, ethylene copolymer polymer, ethylene-vinyl acetate copolymer, polypropylene, ethylene-acrylic acid copolymer, ethylene-acrylic acid ester copolymer, polyamide, polyester, and styrene-isoprene. Copolymer, styrene-divinylbenzene copolymer, ethylene-propylene copolymer, acrylate rubber, polyvinyl acetal, acrylonitrile-butadiene copolymer, styrene, phenoxy, solid epoxy resin, polyurethane, etc. Further, natural and synthetic resins such as terpene resin and rosin, and chelating agents such as EDTA are also included. These resins may be used alone or in combination of two or more.

  The softening point of the resin composition constituting the insulating layer 4 is preferably 130 to 250 ° C. Connection reliability improves that the softening point of a resin composition is 130 degreeC or more. For example, when performing a temperature resistance cycle test of an electronic component using the present invention, in the temperature resistance cycle test with an upper limit of 125 ° C., the insulating layer 4 at the joint is melted or softened even if the electronic component is exposed to 125 ° C. Connection reliability is improved because the mechanical strength is maintained. On the other hand, when the softening point of the resin composition is 250 ° C. or less, when the particle mixture 10 is heated together with another member such as the circuit electrode member, the thermal influence on the other member is reduced. Tend to.

  The thickness of the insulating layer 4 is preferably 0.01 to 0.5 μm. When the thickness of the insulating layer is 0.01 μm or more, in the direction orthogonal to the pressing direction, joining of the melted cores tends to be further suppressed. On the other hand, when the thickness of the insulating layer 4 is 0.5 μm or less, when the insulating layer 4 of the particles 6 is pressed, the core 2 tends to be exposed to the pressed portion of the particles 6 even with a small pressure. Therefore, by setting the thickness of the insulating layer 4 to 0.01 to 0.5 μm, it is possible to further suppress the bonding between the melted cores in the direction orthogonal to the pressing direction, and the insulating layer 4 is pressed. In addition, the core 2 is easily exposed at the pressed portion of the insulating layer 4.

(Second particle)
The second particles 8 are preferably conductive particles. In this case, since the second particles 8 can also pass an electric current, the conductivity of the particle mixture 10 is improved. The second particles 8 are preferably made of a metal such as Au, Ag, Ni, Cu, Co, solder, carbon, or the like. Further, non-conductive glass, ceramics, plastic, or the like coated with a conductive material such as the metal can be used as the second particles 8. At this time, the thickness of the metal layer to be coated is preferably 10 nm or more in order to obtain sufficient conductivity.

  The second particles 8 may be insulating particles. Examples of the insulating material include various rubbers such as styrene butadiene rubber and silicone rubber, various plastics such as polystyrene and epoxy resin, and natural products such as starch and cellulose. By using an insulating material for the second particles 8, the density of the second particles 8 is lowered and the dispersibility in the adhesive composition is improved.

  The average particle diameter of the second particles 8 is preferably 1 to 10 μm. When the average particle diameter of the second particles 8 is 1 μm or more, the molten core is more difficult to be crushed, and thus the molten core tends to be suppressed from being joined in the direction orthogonal to the pressing direction. It is in. On the other hand, when the average particle size of the second particles 8 is 10 μm or less, for example, it is possible to suppress a decrease in the bonding area or contact area between the melted core and the circuit electrode. Therefore, by setting the average particle diameter of the second particles 8 to 1 to 10 μm, it is possible to prevent the melted cores from being joined to each other in the direction orthogonal to the pressurizing direction, and the melted core and the circuit electrode. The bonding area or contact area can be increased.

  The average particle diameter of the second particles 8 with respect to the average particle diameter of the core 2 is preferably 0.5 to 0.9 times. When the average particle size of the second particles 8 is 0.5 times or more of the average particle size of the core 2, the molten core 2 is sufficiently crushed when it is thermocompression-bonded, and is in contact with the first and second electrodes. The area tends to increase, and the possibility that the melted core 2 is crushed too much and adjacent particles 6 are fused with each other tends to be reduced. On the other hand, if the average particle diameter of the second particles 8 is 0.9 times or less than the average particle diameter of the core 2, the core 2 melted when thermocompression bonding is sufficiently crushed and the first and second electrodes The contact area tends to increase. Therefore, when the average particle diameter of the second particles 8 is 0.5 to 0.9 times the average particle diameter of the core 2, the melted core 2 is sufficiently crushed when the thermocompression bonding is performed. The contact area with the second electrode tends to increase, and the possibility that the melted core is crushed too much and the adjacent first particles 6 are fused with each other tends to be reduced.

  The mass ratio of the second particles 8 to the mass of the core 2 is preferably 0.1 to 1.0 times. When the mass of the second particles 8 is 0.1 times or more of the mass of the core 2, the melted core becomes more difficult to be crushed, so that the insulation in the direction orthogonal to the pressing direction tends to be improved. . On the other hand, when the mass of the second particles 8 is not more than 1.0 times the mass of the core 2, the conductivity in the pressurizing direction tends to be improved. Therefore, when the mass of the second particles 8 is 0.1 to 1.0 times the mass of the core 2, the insulation in the direction orthogonal to the pressurizing direction can be improved and the conductivity in the pressurizing direction can be improved. It can be improved.

(Adhesive composition)
The adhesive composition contained in the circuit connection material 1 contains a radical polymerizable compound and a radical polymerization initiator.

  The radical polymerizable compound is a compound having a functional group that is polymerized by radicals. Examples of the radical polymerizable compound include a (meth) acrylate compound, a maleimide compound, a citraconimide compound, and a nadiimide compound. You may use these individually by 1 type or in mixture of 2 or more types. Moreover, the radically polymerizable compound can be used in any state of a monomer or an oligomer, and a monomer and an oligomer may be mixed and used.

  (Meth) acrylate compounds include methyl (meth) acrylate, ethyl (meth) acrylate, isopropyl (meth) acrylate, isobutyl (meth) acrylate, etherene glycol di (meth) acrylate, diethylene glycol di (meth) acrylate, and trimethylol. Propane tri (meth) acrylate, tetramethylene glycol tetra (meth) acrylate, 2-hydroxy-1,3-diaacryloxypropane, 2,2-bis [4- (acryloxymethoxy) phenyl] propane, 2,2- Bis [4- (acryloxyethoxy) phenyl] propane, dicyclopentenyl (meth) acrylate tricyclodecanyl (meth) acrylate, tris (acryloxyethyl) isocyanurate, urethane (meth) acrylate , And the like isocyanuric acid ethylene oxide-modified diacrylate. You may use these individually by 1 type or in mixture of 2 or more types. A (meth) acrylic resin is obtained by radical polymerization of the (meth) acrylate compound.

  A maleimide compound is a compound having at least one maleimide group. As maleimide compounds, phenylmaleimide, 1-methyl-2,4-bismaleimidebenzene, N, N′-m-phenylenebismaleimide, N, N′-p-phenylenebismaleimide, N, N′-4,4 -Biphenylene bismaleimide, N, N'-4,4- (3,3-dimethylbiphenylene) bismaleimide, N, N'-4,4- (3,3-dimethyldiphenylmethane) bismaleimide, N, N'- 4,4- (3,3-diethyldiphenylmethane) bismaleimide, N, N′-4,4-diphenylmethane bismaleimide, N, N′-4,4-diphenylpropane bismaleimide, N, N′-4,4 -Diphenyl ether bismaleimide, N, N'-4,4-diphenylsulfone bismaleimide, 2,2-bis (4- (4-maleimidophenol) Xyl) phenyl) propane, 2,2-bis (3-s-butyl-3,4- (4-maleimidophenoxy) phenyl) propane, 1,1-bis (4- (4-maleimidophenoxy) phenyl) decane, 4,4'-cyclohexylidene-bis (1- (4-maleimidophenoxy) phenoxy) -2-cyclohexylbenzene, 2,2-bis (4- (4-maleimidophenoxy) phenyl) hexafluoropropane . You may use these individually by 1 type or in mixture of 2 or more types.

  A citraconic imide compound is a compound having at least one citraconic imide group. Citraconimide compounds include phenyl citraconimide, 1-methyl-2,4-biscitraconimide benzene, N, N′-m-phenylene biscitraconimide, N, N′-p-phenylene biscitraconimide, N, N '-4,4-biphenylenebiscitraconimide, N, N'-4,4- (3,3-dimethylbiphenylene) biscitraconimide, N, N'-4,4- (3,3-dimethyldiphenylmethane) bis Citraconimide, N, N′-4,4- (3,3-diethyldiphenylmethane) biscitraconimide, N, N-4,4-diphenylmethanebiscitraconeimide, N, N′-4,4-diphenylpropane biscitracon Imide, N, N′-4,4-diphenyl ether biscitraconimide, N, N′-4,4-di Enylsulfone biscitraconimide, 2,2-bis (4- (4-citraconimidophenoxy) phenyl) propane, 2,2-bis (3-s-butyl-3,4- (4-citraconimidophenoxy) phenyl) Propane, 1,1-bis (4- (4-citraconimidophenoxy) phenyl) decane, 4,4′-cyclohexylidene-bis (1- (4-citraconimidophenoxy) phenoxy) -2-cyclohexylbenzene, 2 , 2-bis (4- (4-citraconimidophenoxy) phenyl) hexafluoropropane and the like. You may use these individually by 1 type or in mixture of 2 or more types.

  A nadiimide compound is a compound having at least one nadiimide group. Examples of the nadiimide compound include phenyl nadiimide, 1-methyl-2,4-bisnadiimidebenzene, N, N′-m-phenylenebisnadiimide, N, N′-p-phenylenebisnadiimide, N, N′-4, 4-biphenylenebisnadiimide, N, N′-4,4- (3,3-dimethylbiphenylene) bisnadiimide, N, N′-4,4- (3,3-dimethyldiphenylmethane) bisnadiimide, N, N′-4 , 4- (3,3-Diethyldiphenylmethane) bisnadiimide, N, N′-4,4-diphenylmethanebisnadiimide, N, N′-4,4-diphenylpropanebisnadiimide, N, N′-4,4-diphenyl ether Bisnadiimide, N, N′-4,4-diphenylsulfone bisnadiimide, 2,2-bis (4- (4-nadiimidophenol) Xyl) phenyl) propane, 2,2-bis (3-s-butyl-3,4- (4-nadiimidophenoxy) phenyl) propane, 1,1-bis (4- (4-nadiimidophenoxy) phenyl) Decane, 4,4′-cyclohexylidene-bis (1- (4-nadiimidophenoxy) phenoxy) -2-cyclohexylbenzene, 2,2-bis (4- (4-nadiimidophenoxy) phenyl) hexafluoropropane Etc. You may use these individually by 1 type or in mixture of 2 or more types.

  Furthermore, as the radical polymerizable compound, a radical polymerizable compound having a phosphate structure may be used.

  A radically polymerizable compound having a phosphate structure is preferable because it can improve the adhesive force of the adhesive composition to an inorganic substance such as a metal. The amount of the radical polymerizable compound having a phosphate ester structure is preferably from 0.1 to 30 parts by weight, more preferably from 0.5 to 10 parts by weight, based on 100 parts by weight of the solid content of the adhesive composition. 0.5-5 mass parts is further more preferable. The radically polymerizable compound having a phosphoric ester structure is obtained as a reaction product of phosphoric anhydride and 2-hydroxyethyl (meth) acrylate. Specific examples include mono (2-methacryloyloxyethyl) acid phosphate, di (2-methacryloyloxyethyl) acid phosphate (phosphate ester dimethacrylate), and the like. You may use these individually by 1 type or in mixture of 2 or more types.

  As the radical polymerizable compound, it is preferable to use a combination of a (meth) acrylate compound and a radical polymerizable compound having a phosphate ester structure. In the case of such a combination, the adhesive strength of the adhesive composition is further improved as compared with the case where a (meth) acrylate compound and a radical polymerizable compound having a phosphate ester structure are used alone.

  The radical polymerization initiator is not particularly limited as long as it is a compound that generates radicals by light irradiation and / or heating. As such a radical polymerization initiator, a compound that generates a radical upon irradiation with light of 150 to 750 nm and / or heating at 80 to 200 ° C. is preferable, and specifically, a peroxide, an azo compound, or the like is preferable. These are appropriately selected in consideration of the intended connection temperature, connection time, storage stability, and the like.

  As the peroxide, an organic peroxide is preferable from the viewpoint of high reactivity and storage stability. Organic peroxide having a half-life of 10 hours at a temperature of 40 ° C or higher and a half-life of 1 minute at a temperature of 180 ° C or lower. Organic peroxides having a half-life of 10 hours at a temperature of 50 ° C. or more and a half-life of 1 minute at a temperature of 170 ° C. or less are particularly preferred. When the connection time is 10 seconds or less, the blending amount of the radical polymerization initiator for obtaining a sufficient reaction rate is preferably 1 to 20% by mass based on the total solid content of the adhesive composition, preferably 2 ˜15% by weight is particularly preferred.

  Specific examples of the organic peroxide include diacyl peroxide, peroxydicarbonate, peroxyester, peroxyketal, dialkyl peroxide, hydroperoxide, silyl peroxide, and the like. Among them, peroxyesters, dialkyl peroxides, hydroperoxides, and silyl peroxides have a chlorine ion or organic acid concentration of 5000 ppm or less in the initiator, and less organic acids are generated after thermal decomposition. This is particularly preferable because it can suppress corrosion of the steel.

  Diacyl peroxides include isobutyl peroxide, 2,4-dichlorobenzoyl peroxide, 3,5,5-trimethylhexanoyl peroxide, octanoyl peroxide, lauroyl peroxide, stearoyl peroxide, succinic peroxide, benzoyl Examples include peroxytoluene and benzoyl peroxide.

  Examples of peroxydicarbonate include di-n-propyl peroxydicarbonate, diisopropyl peroxydicarbonate, bis (4-t-butylcyclohexyl) peroxydicarbonate, di-2-ethoxymethoxyperoxydicarbonate, di ( 2-ethylhexyl peroxy) dicarbonate, dimethoxybutyl peroxydicarbonate, di (3-methyl-3-methoxybutylperoxy) dicarbonate and the like.

  Peroxyesters include cumylperoxyneodecanoate, 1,1,3,3-tetramethylbutylperoxyneodecanoate, 1-cyclohexyl-1-methylethylperoxynoedecanoate, and t-hexyl. Peroxyneodecanoate, t-butylperoxypivalate, 1,1,3,3-tetramethylbutylperoxy-2-ethylhexanoate, 2,5-dimethyl-2,5-di (2- Ethylhexanoylperoxy) hexane, 1-cyclohexyl-1-methylethylperoxy-2-ethylhexanoate, t-hexylperoxy-2-ethylhexanoate, t-butylperoxy-2-ethylhexanoate Nate, t-butylperoxyisobutyrate, 1,1-bis (t-butylperoxy) cyclohexane, -Hexylperoxyisopropyl monocarbonate, t-butylperoxy-3,5,5-trimethylhexanonate, t-butylperoxylaurate, 2,5-dimethyl-2,5-di (m-toluoyl par Oxy) hexane, t-butyl peroxyisopropyl monocarbonate, t-butyl peroxy-2-ethylhexyl monocarbonate, t-hexyl peroxybenzoate, t-butyl peroxyacetate and the like.

  Peroxyketals include 1,1-bis (t-hexylperoxy) -3,3,5-trimethylcyclohexane, 1,1-bis (t-hexylperoxy) cyclohexane, 1,1-bis (t- Butyl peroxy) -3,3,5-trimethylcyclohexane, 1,1- (t-butylperoxy) cyclododecane, 2,2-bis (t-butylperoxy) decane and the like.

  Dialkyl peroxides include α, α′-bis (t-butylperoxy) diisopropylbenzene, dicumyl peroxide, 2,5-dimethyl-2,5-di (t-butylperoxy) hexane, and t-butyl. Cumyl peroxide and the like.

  Examples of the hydroperoxide include diisopropylbenzene hydroperoxide and cumene hydroperoxide.

  Examples of silyl peroxides include t-butyltrimethylsilyl peroxide, bis (t-butyl) dimethylsilyl peroxide, t-butyltrivinylsilyl peroxide, bis (t-butyl) divinylsilyl peroxide, and tris (t-butyl). Examples thereof include vinylsilyl peroxide, t-butyltriallylsilyl peroxide, bis (t-butyl) diallylsilyl peroxide, and tris (t-butyl) allylsilyl peroxide.

  These radical polymerization initiators can be used singly or in combination of two or more, and may be used by mixing a decomposition accelerator, an inhibitor and the like.

  In addition, those obtained by coating these radical polymerization initiators with a polyurethane-based or polyester-based polymeric substance to form a microcapsule are preferable because the pot life is extended.

  When the adhesive composition is used as a circuit connecting material, the concentration of chlorine ions and organic acids contained in the radical polymerization initiator is 5000 ppm or less in order to suppress corrosion of the electrodes of the circuit member. Is preferred. Furthermore, a radical polymerization initiator that generates less organic acid after thermal decomposition is more preferable. Moreover, since the stability after hardening of adhesive composition improves, it is preferable to have a mass retention of 20 mass% or more after leaving open for 24 hours at room temperature and normal pressure.

  Moreover, adhesive composition may contain radical polymerization inhibitors, such as hydroquinone and methyl ether hydroquinone, in the range which does not impair sclerosis | hardenability as needed.

  The adhesive composition may include a thermosetting resin other than the radical polymerizable compound. Examples of such a thermosetting resin include an epoxy resin. Epoxy resins include bisphenol A type epoxy resin, bisphenol F type epoxy resin, bisphenol S type epoxy resin, phenol novolac type epoxy resin, cresol novolac type epoxy resin, bisphenol A novolak type epoxy resin, bisphenol F novolak type epoxy resin, fat Examples thereof include cyclic epoxy resins, glycidyl ester type epoxy resins, glycidyl amine type epoxy resins, hydantoin type epoxy resins, isocyanurate type epoxy resins, and aliphatic chain epoxy resins. These epoxy resins may be halogenated or hydrogenated. These epoxy resins may be used alone or in combination of two or more.

  Moreover, what is used as a hardening | curing agent of a normal epoxy resin can be used as a hardening | curing agent of the said epoxy resin. Specific examples include amines, phenols, acid anhydrides, imidazoles, dicyandiamide and the like. Furthermore, tertiary amines and organic phosphorus compounds that are usually used as curing accelerators may be used as appropriate.

  Further, as a method of reacting the epoxy resin, in addition to using the above curing agent, cationic polymerization may be performed using a sulfonium salt, an iodonium salt, or the like.

  The adhesive composition may contain a polymer compound in order to impart film formability, adhesiveness, and stress relaxation during curing. Examples of the polymer compound include polyvinyl butyral resin, polyvinyl formal resin, polyester resin, polyamide resin, polyimide resin, xylene resin, phenoxy resin, polyurethane resin, urea resin, and the like.

  These polymer compounds preferably have a molecular weight of 10,000 to 10,000,000. Further, these polymer compounds may be modified with radically polymerizable functional groups, and in this case, heat resistance is improved. Furthermore, these polymer compounds may contain a carboxyl group. The blending amount of the polymer compound in the adhesive composition is preferably 2 to 80% by mass, more preferably 5 to 70% by mass, and particularly preferably 10 to 60% by mass with respect to the total solid content in the adhesive composition. preferable. When the blending amount of the polymer compound is 2% by mass or more, stress relaxation and adhesive force tend to be improved. On the other hand, when it is 80% by mass or less, the fluidity tends to be difficult to decrease.

  A filler, softener, accelerator, anti-aging agent, colorant, flame retardant, and coupling agent may be added to the adhesive composition as appropriate.

  In the adhesive composition demonstrated above, it is preferable to contain 0.5-30 mass parts of radical polymerization initiators with respect to 100 mass parts of radically polymerizable compounds, and containing 1.0-10 mass parts. More preferred. When the content of the radical polymerization initiator is 0.5 parts by mass or more, the curing reaction proceeds sufficiently and curing tends to be sufficient. On the other hand, when it is 30 parts by mass or less, the storage stability tends to be difficult to decrease.

  Moreover, it is preferable that it is 1-20 mass% with respect to the whole quantity of the circuit connection material 1, and, as for the content rate of the particle mixture 10 in the circuit connection material 1, it is more preferable that it is 2-10 mass%. When the content ratio is 1% by mass or more, good conduction tends to be easily obtained. On the other hand, when it is 20% by mass or less, the possibility of causing a short circuit between adjacent circuits can be reduced.

  The usage form of the circuit connecting material 1 is not particularly limited. For example, the particle mixture 10 is dispersed in a solution obtained by dissolving each component in the adhesive composition in an organic solvent such as toluene or ethyl acetate. Can do. Moreover, it can also use as a molded object (For example, the film-form circuit connection material 12 mentioned later; refer FIG. 2) shape | molded in the predetermined shape by removing the solvent from the solution in which the particle mixture 10 is dispersed.

(Circuit connection material)
The circuit connection material 1 of this embodiment includes a first circuit member in which a plurality of first circuit electrodes are formed on the main surface of the first circuit board, and a plurality of circuits on the main surface of the second circuit board. A circuit connection material for connecting a second circuit member on which a second circuit electrode is formed in a state where the first and second circuit electrodes face each other, and is bonded to the particle mixture 10 described above. Agent composition. It is preferable that the circuit connection material 1 of this embodiment has anisotropic conductivity.

  When the circuit connection material 1 of the present embodiment is interposed between the first and second circuit members, and the circuit connection material 1 is heated and pressurized in a predetermined direction via the first and second circuit members, The first and second circuit members are electrically connected by the circuit connecting material 1. Since the circuit connection material 1 of the present embodiment contains the particle mixture 10 described above, the circuit connection material 1 improves the conductivity in the pressurizing direction during heating and pressurization in a predetermined direction, and pressurizes. The insulation in the direction orthogonal to the direction is improved.

  Moreover, it is preferable that the content rate of the particle mixture 10 with respect to the gross mass of the said circuit connection material 1 is 1-20 mass%, and it is more preferable that it is 2-20 mass%. When the content ratio of the particle mixture 10 with respect to the total mass of the circuit connecting material 1 is 1 or more, the conductivity in the pressurizing direction tends to be improved when the circuit connecting material 1 is heated and pressed in a predetermined direction. On the other hand, when the content ratio of the particle mixture 10 with respect to the total mass of the circuit connection material 1 is 20% by mass or less, when the circuit connection material 1 is heated and pressed in a predetermined direction, the insulation in the direction orthogonal to the pressing direction is obtained. It tends to improve. Moreover, since the content rate of the 2nd particle | grains 8 which cannot contribute relatively to adhesion or joining with a circuit member becomes relatively low, it exists in the tendency for the mechanical strength of the connection structure of the circuit member obtained to improve. Therefore, when the content ratio of the particle mixture 10 with respect to the total mass of the circuit connection material 1 is 1 to 20% by mass, the conductivity in the pressurizing direction is improved when the circuit connection material 1 is heated and pressed in a predetermined direction. In addition, the insulation in the direction orthogonal to the pressurizing direction can be improved. In the present invention, the first particles and the second particles each have a content ratio of the first particles with respect to the total mass of the circuit connection material 1 of 1 to 10% by mass, and the total mass of the circuit connection material 1 It is preferable that the content ratio of the second particles to 1 to 10% by mass.

  Moreover, in the circuit connection material 1 of this embodiment, since the core 2 is coat | covered with the insulating layer 4, the core 2 is hard to oxidize. For this reason, the connection resistance between the 1st circuit electrode and 2nd circuit electrode which oppose can be reduced further.

(Film-like circuit connection material)
FIG. 2 is a cross-sectional view schematically showing a film-like circuit connecting material. A film-like circuit connecting material 12 shown in FIG. 2 is obtained by forming the above-described circuit connecting material 1 into a film shape. By forming the circuit connection material in a film like this, problems such as tearing, cracking, and stickiness of the circuit connection material hardly occur, and handling of the circuit connection material becomes easy. The film-like circuit connecting material 12 has a film-like insulating part 14 made of the above-described adhesive composition and a particle mixture 10 dispersed in the insulating part 14.

  The film-like circuit connecting material 12 may have a multilayer structure (not shown) composed of two or more layers having a Tg (glass transition temperature) of the adhesive composition different by 5 ° C. or more when cured.

  For example, the film-like circuit connecting material 12 is prepared by dissolving an adhesive composition in a solvent and dispersing the particle mixture 10 on a support (PET (polyethylene terephthalate) film) using a coating apparatus, It can be produced by drying with hot air for a predetermined time at a temperature at which the adhesive composition does not cure.

  The thickness of the film-like circuit connecting material 12 is preferably 2 to 20 μm. When the thickness of the film-like circuit connecting material 12 is 2 μm or more, there is a tendency that a sufficient amount of circuit connecting material can be filled between the facing circuit members. On the other hand, when it is 20 μm or less, the adhesive composition between the circuit electrodes can be sufficiently removed, and it is easy to ensure the conduction between the circuit electrodes.

(Circuit member connection structure)
FIG. 3 is a cross-sectional view schematically showing a circuit member connection structure according to an embodiment of the present invention. The circuit member connection structure 24 shown in FIG. 3 includes a first circuit member 20 having a plurality of first circuit electrodes 22 formed on a main surface 21a of the first circuit board 21, and a second circuit board. A second circuit member 30 having a plurality of second circuit electrodes 32 formed on a main surface 31a of 31 is connected. The connection structure 24 includes a circuit connection member 26 provided between the main surface 21 a of the first circuit board 21 and the main surface 31 a of the second circuit board 31. On the main surface 21 a of the first circuit board 21, an insulating layer (not shown) may be formed according to circumstances. In addition, an insulating layer (not shown) may be formed on the main surface 31a of the second circuit board 31 in some cases.

  The circuit members 20 and 30 are not particularly limited as long as electrodes that require electrical connection are formed. Specific examples include glass or plastic substrates on which electrodes are formed of ITO or Au used in liquid crystal displays, printed wiring boards, ceramic wiring boards, flexible wiring boards, semiconductor silicon chips, and the like. Used in combination as needed. As described above, in the present embodiment, materials such as printed wiring boards and polyimides, metals such as copper and aluminum, ITO (indium tin oxide), silicon nitride (SiNx), silicon dioxide (SiO2), and the like are used. Circuit members having various surface states such as inorganic materials can be used.

  The circuit connection member 26 is made of a cured product of the circuit connection material 1 described above, and connects the circuit members 20 and 30 with the circuit electrodes 22 and 32 facing each other. The circuit connecting member 26 includes a low melting point metal portion 16 made of a low melting point metal that has formed the core 2 (FIG. 2) of the first particle 6 of the film-like circuit connecting material 12, and the first part of the film-like circuit connecting material 12. Insulating portion 18 made of a cured product of the resin composition constituting insulating layer 4 (FIG. 2) of one particle 6, second particles 8 (FIG. 2) of film-like circuit connecting material 12, and film-like And an insulating part 11 made of a cured product of the adhesive composition contained in the insulating part 14 of the circuit connecting material 12.

  The first circuit electrode 22 and the second circuit electrode 32 are electrically and mechanically connected via the low melting point metal part 16. The low melting point metal part 16 is bonded and solidified to the first circuit electrode 22 and the second circuit electrode 32 after the core 2 is melted. For this reason, the low melting point metal portion 16 is metal-bonded to the first circuit electrode 22 and the second circuit electrode 32. Therefore, the connection resistance between the circuit electrodes 22 and 32 is sufficiently reduced, and the first circuit electrode 22 and the second circuit electrode 32 can be firmly fixed. Therefore, the flow of current between the circuit electrodes 22 and 32 can be made smooth, and the functions of the circuit can be fully exhibited.

  In addition, the first circuit electrode 22 and the second circuit electrode 32 can be more firmly fixed by the insulating portion 18. Furthermore, the insulating part 18 can further suppress the conduction between adjacent low melting point metal parts 16. Therefore, the short circuit between the adjacent circuit electrodes 22 and 32 can be further suppressed.

  In such a circuit member connection structure 24, the connection resistance between the circuit electrode 22 and the circuit electrode 32 facing each other can be sufficiently reduced, and the insulation between the adjacent circuit electrodes 22 and between the adjacent circuit electrodes 32 can be reduced. Insulation is sufficiently improved. Further, the circuit electrode 22 and the circuit electrode 32 that face each other are firmly fixed by the circuit connection member 26.

(Method for manufacturing circuit member connection structure)
Next, with reference to FIGS. 4A to 4C, a method for manufacturing the above-described circuit member connection structure 24 will be described. FIG. 4A to FIG. 4C are cross-sectional views schematically showing each step of the method for manufacturing the circuit member connection structure.

  First, the first circuit member 20 and the film-like circuit connecting material 12 described above are prepared (see FIG. 4A). Next, the film-like circuit connecting material 12 is placed on the surface of the first circuit member 20 on which the first circuit electrode 22 is formed. For example, when the film-like circuit connecting material 12 is attached on a support (not shown), the film-like circuit connecting material 12 side is directed to the first circuit member 20 so that the first circuit member 20 is directed to the first circuit member 20. It is placed on the circuit member 20. At this time, since the film-like circuit connecting material 12 is in the form of a film, it is easy to handle. Therefore, the film-like circuit connecting material 12 can be easily interposed between the first circuit member 20 and the second circuit member 30, and the connection between the first circuit member 20 and the second circuit member 30 is possible. Work can be done easily.

  Then, the film-like circuit connecting material 12 is pressurized (pressed in the directions of arrows A and B in FIG. 4A) in a direction to be pressed against the circuit member 20, and the film-like circuit connecting material 12 is turned into the first circuit. Temporarily connected to the member 20 (see FIG. 4B). At this time, you may pressurize, heating. However, the heating temperature is set to a temperature at which the adhesive composition in the film-like circuit connecting material 12 is not cured, that is, a temperature lower than the temperature at which the radical polymerization initiator generates radicals.

  Subsequently, as shown in FIG. 4C, the second circuit member 30 is placed on the film-like circuit connection material 12 so that the second circuit electrode 32 faces the first circuit member 20. . For example, when the film-like circuit connecting material 12 is attached on a support (not shown), the second circuit member 30 is placed on the film-like circuit connecting material 12 after the support is peeled off. .

  And the film-form circuit connection material 12 is pressurized through the circuit members 20 and 30 in the direction of arrow A and arrow B of FIG.4 (c), heating. The heating temperature at this time is a temperature at which the radical polymerization initiator can generate radicals. As a result, the radical polymerization initiator generates radicals and polymerization of the radical polymerizable compound is started. Then, the adhesive composition of the insulating portion 14 is cured. The heating temperature is, for example, 90 to 200 ° C., and the connection time is, for example, 1 second to 10 minutes. These conditions are appropriately selected depending on the application to be used, the adhesive composition, and the circuit member, and may be post-cured as necessary. In this way, the film-like circuit connecting material 12 is cured and the main connection is performed, so that a circuit member connection structure 24 as shown in FIG. 3 is obtained.

  During such a heating / pressurizing process, the film-like circuit connecting material 12 is heated and pressurized in a predetermined direction via the first and second circuit electrodes. Then, the first particles 6 and the second particles 8 dispersed in the film-like circuit connecting material 12 are sandwiched between the circuit electrode 22 and the circuit electrode 32 facing each other. Thereby, first, at the softening point of the resin composition, the insulating layer 4 of the first particles 6 is softened and pressed by the first circuit electrode 22 and the second circuit electrode 32, thereby The insulating layer 4 is partially removed selectively at the pressed portion of the particle 6, and the core 2 is exposed from the insulating layer 4. Thereafter, when further heated, the core 2 melts at the melting point of the low melting point metal. As a result, the first and second circuit electrodes 22 and 32 and the molten core are metal-bonded.

  The film-like circuit connecting material 12 includes the second particles 8, and the second particles 8 have a higher melting point or higher softening point than the low melting point metal part 16 (core 2), and are higher than the core 2. Since the particle size is small, it functions as a spacer between the circuit electrode 22 and the circuit electrode 32, and the melted core 2 is not easily crushed by the first and second circuit electrodes. Therefore, it is avoided that the 1st particle | grains 6 are crushed excessively, and it can suppress that the molten cores 2 join in the direction orthogonal to a pressurization direction. Furthermore, since portions other than the above-described exposed portions on the surface 2a of the core 2 are covered with the insulating layer 4, it is possible to further suppress the fusion of the melted cores 2 in the direction orthogonal to the pressing direction. .

  Moreover, in the particle mixture 10 of this embodiment, since the core 2 is coat | covered with the insulating layer 4, the core 2 is hard to oxidize. Therefore, when the particle mixture 10 is heated and pressurized in a predetermined direction, conductivity in the pressing direction is improved.

  When the circuit member connection structure 24 is manufactured as described above, in the circuit member connection structure 24 obtained, the connection resistance between the circuit electrode 22 and the circuit electrode 32 facing each other can be sufficiently reduced and adjacent to each other. The insulation between the circuit electrodes 22 and the insulation between the adjacent circuit electrodes 32 are sufficiently improved, and the possibility of a short circuit is reduced.

  By heating the film-like circuit connecting material 12, the adhesive composition is cured to form the insulating portion 11 in a state where the distance between the first circuit electrode 22 and the second circuit electrode 32 is sufficiently small. The core 2 is solidified after being melted and joined to the first circuit electrode 22 and the second circuit electrode 32, so that the first circuit member 20 and the second circuit member 30 connect the circuit connection member 26. It is firmly connected via. In the circuit member connection structure 24 obtained, the circuit connection member 26 is made of a cured product of the circuit connection material, and therefore the adhesive strength of the circuit connection member 26 is sufficiently high with respect to the circuit member 20 or 30.

  Furthermore, since the core 2 is mainly composed of a low melting point metal, the process temperature when the circuit member connection structure 24 is manufactured becomes low. Accordingly, since the parts constituting the circuit member connection structure 24 are not required to have so much heat resistance, the range of material selection for the parts is widened.

[Second Embodiment]
(Connection material)
The connection material of this embodiment contains the above-mentioned particle mixture 10 and an adhesive composition. The connection material of this embodiment is not limited to the above-described circuit connection material, and is a connection material for connecting the first and second circuit electrodes facing each other. When this connection material is interposed between the first and second circuit electrodes, and the connection material is heated and pressurized in a predetermined direction via the first and second circuit electrodes, the first and second circuit electrodes are Electrically connected by connecting material. Since the connection material of the present embodiment contains the particle mixture 10 described above, this connection material improves conductivity in the pressurizing direction and is orthogonal to the pressurizing direction during heating and pressurizing in a predetermined direction. The insulation in the direction is improved.

  Moreover, it is preferable that the content rate of the particle mixture 10 with respect to the gross mass of the said connection material is 1-20 mass%. When the content ratio of the particle mixture 10 with respect to the total mass of the connecting material is 1% by mass or more, the conductivity in the pressurizing direction tends to be improved when the connecting material is heated and pressurized in a predetermined direction. On the other hand, when the content ratio of the particle mixture 10 with respect to the total mass of the connecting material is 20% by mass or less, when the connecting material is heated and pressurized in a predetermined direction, the insulating property in a direction orthogonal to the pressing direction tends to be improved. is there. Moreover, since the content rate of the 2nd particle | grains 8 which hardly contributes to adhesion | attachment or joining with a circuit electrode becomes relatively low, it exists in the tendency for the mechanical strength of the connection structure of the circuit electrode obtained to improve. Therefore, when the content ratio of the particle mixture 10 with respect to the total mass of the connection material is 1 to 20% by mass, when the connection material is heated and pressurized in a predetermined direction, the conductivity in the pressurizing direction can be improved and the addition can be increased. The insulation in the direction orthogonal to the pressure direction can be improved.

(Film connection material)
The film-like connection material of the present embodiment is formed by forming the above-mentioned circuit connection material 1 into a film shape, similarly to the film-like circuit connection material 12 shown in FIG. By forming the circuit connection material in a film shape in this way, problems such as tearing, cracking, and stickiness of the connection material hardly occur, and handling of the connection material becomes easy.

(Circuit electrode connection structure)
FIG. 5 is a cross-sectional view schematically showing a semiconductor device as a circuit electrode connection structure of the present embodiment. A semiconductor device 100 shown in FIG. 5 includes a semiconductor element 50 (first circuit electrode) and a substrate 60 that supports the semiconductor element 50. Between the semiconductor element 50 and the substrate 60, a semiconductor element connecting member 40 (connecting member) for electrically and mechanically connecting them is provided. The semiconductor element connection member 40 is provided on the main surface 60 a of the substrate 60. The semiconductor element 50 is provided on the semiconductor element connection member 40.

  A plurality of circuit patterns 61 (second circuit electrodes) are formed on the substrate 60. The circuit pattern 61 is disposed to face the semiconductor element 50. The semiconductor element connection member 40 is provided between the semiconductor element 50 and the circuit pattern 61 and electrically and mechanically connects them. The semiconductor element connection member 40 and the semiconductor element 50 are sealed with a sealing material 70.

  The constituent material of the semiconductor element 50 is not particularly limited, but is a group IV semiconductor material such as silicon and germanium, GaAs, InP, GaP, InGaAs, InGaAsP, AlGaAs, InAs, GaInP, AlInP, AlGaInP, GaNAs, GaNP, GaInNAs, III-V group compound semiconductor materials such as GaInNP, GaSb, InSb, GaN, AlN, InGaN, InNAsP, II-VI group compound semiconductor materials such as HgTe, HgCdTe, CdMnTe, CdS, CdSe, MgSe, MgS, ZnSe, and ZeTe, Various materials such as CuInSe (ClS) can be mentioned.

  The semiconductor element connection member 40 is made of a cured product of the circuit connection material 1 described above. Similar to the circuit connection member 26, the semiconductor element connection member 40 includes, for example, the low melting point metal part 16, the insulating part 18, the second particle 8, and the insulating part 11. In the semiconductor device 100, the semiconductor element 50 and the circuit pattern 61 are electrically connected via a low melting point metal portion 16 made of a low melting point metal. For this reason, the connection resistance between the semiconductor element 50 and the circuit pattern 61 is sufficiently reduced. Therefore, the flow of current between the semiconductor element 50 and the circuit pattern 61 can be made smooth, and the functions of the semiconductor element 50 can be sufficiently exhibited. Further, since the semiconductor element connection member 40 has excellent anisotropic conductivity, the insulation between the adjacent circuit patterns 61 is sufficiently improved. Therefore, occurrence of a short circuit between adjacent circuit patterns 61 can be suppressed.

  Further, in the semiconductor element connection member 40, the low melting point metal portion 16, the semiconductor element 50, and the circuit pattern 61 are metal-bonded, so that the bonding strength of the semiconductor element connection member 40 to the semiconductor element 50 and the substrate 60 is sufficient. It becomes high and this state can be maintained for a long time. Therefore, the long-term reliability of the electrical characteristics between the semiconductor element 50 and the substrate 60 can be sufficiently increased.

  As mentioned above, although preferred embodiment of this invention was described in detail, this invention is not limited to the said embodiment.

  For example, in the said embodiment, although the connection structure of a circuit member is manufactured using the film-form circuit connection material 12, it replaces with the film-form circuit connection material 12, and may use the circuit connection material 1 which is not a film form. Good. In this case, for example, if the circuit connection material 1 is dissolved in a solvent and the solution is applied to either the first circuit member 20 or the second circuit member 30 and dried, the circuit connection material 1 is separated between the circuit members 20 and 30. The circuit connection material 1 can be interposed.

  In addition, in the method for manufacturing a circuit member connection structure, in addition to a radical polymerization initiator that generates radicals by heating or light irradiation, a radical polymerization initiator that generates radicals by ultrasonic waves, electromagnetic waves, or the like is used as necessary. May be.

  EXAMPLES Hereinafter, although this invention is demonstrated more concretely based on an Example and a comparative example, this invention is not limited to a following example.

Example 1
(Production of particles)
First, Sn-58Bi conductive particles were prepared as a core. Solder paste L20 (Solder component: Sn-58Bi) manufactured by Senju Metal Co., Ltd. was dissolved in acetone to separate the conductive particle component. Next, particles having an average particle diameter of 5 μm were classified using a vibration sieve.

  Subsequently, an insulating layer was formed on the surface of the conductive particles. As a material for the insulating layer, a 1% by mass dimethylformamide (DMF) solution of paraprene P-25M (thermoplastic polyurethane resin, softening point 130 ° C., trade name, manufactured by Nippon Elastolan Co., Ltd.) was added, and the conductive particles were added and stirred. . Thereafter, spray drying was carried out at 100 ° C. for 10 minutes using a spray dryer (GA-32 type manufactured by Yamato Scientific Co., Ltd.) to obtain coated particles. The average thickness of the coating layer at this time was about 1 μm as a result of cross-sectional observation with an electron microscope (SEM). In this way, first particles were produced.

  Next, conductive particles (Micropearl AU, average particle size 4 μm) made by Sekisui Chemical Co., Ltd. were prepared as second particles. The average particle size of the second particles was 0.8 times the average particle size of the core 2. there were.

(Production of film circuit connection material)
On the other hand, a film-like circuit connecting material was prepared according to the following procedure. First, 50 g of phenoxy resin (manufactured by Union Carbide Corporation, trade name PKHC, average molecular weight 45,000) is toluene (boiling point 110.6 ° C., SP value 8.90) / ethyl acetate (boiling point 77.1 ° C.). , SP value 9.10) = 50/50 was dissolved in a mixed solvent to prepare a phenoxy resin solution having a solid content of 40% by mass.

  As the radical polymerizable compound, hydroxyethyl glycol dimethacrylate (manufactured by Kyoeisha Chemical Co., Ltd., trade name: 80MFA) and phosphate ester dimethacrylate (manufactured by Kyoeisha Chemical Co., Ltd., trade name: P-2M) were prepared.

  As a radical polymerization initiator, di-2-ethylhexyl peroxydicarbonate (manufactured by NOF Corporation, trade name Parroyl OPP) was prepared.

The materials prepared as described above were blended at the solid content mass ratio shown below to obtain an adhesive composition. Furthermore, the above-mentioned particle mixture was added and dispersed in the adhesive composition so as to be 3% by volume with respect to the total amount of the circuit connecting material.
・ PKHC: 50
・ 80MFA: 50
・ P-2M: 10
・ Paroyle OPP: 5

  Next, the obtained solution was applied to a fluororesin film having a thickness of 80 μm using a coating apparatus, and dried with hot air at 70 ° C. for 10 minutes to obtain a film-like circuit connection material having a thickness of 20 μm. The obtained film-like circuit connecting material showed sufficient flexibility at room temperature (25 ° C.).

(Production of circuit member connection structure)
Next, a flexible substrate (trade name COF TEG_50A, manufactured by Hitachi Ultra LSI Systems Co., Ltd.) having an Au plating circuit having a line width of 25 μm, a pitch of 50 μm, and a thickness of 8 μm, and an Au bump having a bump size of 30 μm × 100 μm and a pitch of 50 μm A semiconductor element (manufactured by Hitachi Ultra LSI Systems, Inc., trade name JTEG Phase 6_50) was prepared. The above-mentioned film-like circuit connecting material is placed between the FPC board and the semiconductor element, and heated for 15 seconds at 160 ° C. and 3 MPa using a thermocompression bonding apparatus (heating method: constant heat type, manufactured by Toray Engineering Co., Ltd.) Pressurization in a predetermined direction was performed. Thus, a circuit member connection structure (semiconductor element / flexible substrate connection structure) was produced.

(Example 2)
A circuit connection material was prepared in the same manner as in Example 1 except that plastic particles having an average particle diameter of 4 μm (Micropearl SP manufactured by Sekisui Chemical Co., Ltd.) were used as the second particles, and a connection structure (semiconductor element) / Flexible substrate connection structure).

(Comparative Example 1)
Circuit connection material as in Example 1 except that Au-plated plastic particles (Micropearl AU manufactured by Sekisui Chemical Co., Ltd.) having an average particle diameter of 5 μm were used as the first particles, and the second particles were not added. And a connection structure (semiconductor element / flexible substrate connection structure) was obtained.

(Comparative Example 2)
A circuit connection material was prepared in the same manner as in Example 1 except that the insulating layer was not formed on the Sn-Bi particles, and a connection structure (semiconductor element / flexible substrate connection structure) was obtained.

(Measurement of connection resistance)
The connection resistance between the circuit members facing each other in the connection structures produced in the above Examples and Comparative Examples was measured. Specifically, the connection resistance of a circuit in which all the electrodes of each connection structure were connected with a daisy chain was measured using a DIGITAL MULTITIMER R6871E manufactured by ADVANTEST. At this time, the measurement current was 1 mA. The measurement results were as shown in Table 1. When the circuit connecting material having the low melting point metal is used for the core of the first particle (Examples 1 and 2), the conduction is made only by the contact of the high melting point metal (Au) having no low melting point metal layer. The connection resistance was lower than when the secured circuit connection material was used (Comparative Example 1). Moreover, when the insulating layer was not formed on the first particles (Comparative Example 2), a short circuit (short circuit) was observed between adjacent electrodes.

(Temperature cycle life)
The temperature resistance cycle life of the connection structures produced in the above examples and comparative examples was evaluated. The temperature range in the measurement was a lower limit of −40 ° C. and an upper limit of 125 ° C., and the holding time at the lower limit and the upper limit temperature was 15 minutes each. A series of steps of heating from normal temperature to the upper temperature limit, cooling to the lower temperature limit, and then returning to the normal temperature was defined as one cycle, and this cycle was repeated to evaluate temperature cycle resistance. And it took out from the temperature cycle test apparatus every 100 cycles, measured connection resistance, and measured the cycle number until an open defect generate | occur | produces. The measurement results are as shown in Table 1. When the circuit connecting material having a low melting point metal is used for the core of the first particle (Examples 1 and 2), the conduction is ensured only by the contact of the high melting point metal (Au) without the low melting point metal layer. It was confirmed that the temperature cycle life was longer than the circuit connection material (Comparative Example 1). In addition, when conductive particles that do not have an insulating layer are used, adjacent conductive particles are fused together when a connection structure is produced, and the adjacent electrodes become conductive and short-circuited. There was a phenomenon.

DESCRIPTION OF SYMBOLS 1 ... Circuit connection material, 2 ... Core, 2a ... Core surface, 4 ... Insulating layer, 6 ... 1st particle, 8 ... 2nd particle, 10 ... Particle mixture, 11, 14 ... Insulating part, 12 ... Film 16 ... low melting point metal part, 18 ... insulating part, 20 ... first circuit member, 21 ... first circuit board, 21a ... main surface of the first circuit board, 22 ... first circuit Electrode, 24 ... Circuit member connection structure, 26 ... Circuit connection member, 30 ... Second circuit member, 31 ... Second circuit board, 31a ... Main surface of second circuit board, 32 ... Second circuit electrode 40 ... Semiconductor element connection member (connection member), 50 ... Semiconductor element (first circuit electrode), 60 ... Substrate, 60a ... Main surface of substrate, 61 ... Circuit pattern (second circuit electrode), 70 ... Sealing Stop material, 100... Semiconductor device.

Claims (4)

A circuit connection material for connecting the first circuit electrode and the second circuit electrode sandwiched between a first circuit electrode and a second circuit electrode facing each other,
An adhesive composition having fluidity by heating, first particles, and second particles;
The first particles are:
A core mainly composed of a low melting point metal having a melting point of 130 to 250 ° C., and an insulating layer made of a resin composition covering the surface of the core and having a softening point lower than the melting point of the low melting point metal, Have
The second particles are
The average particle size is smaller than the core, the main component is a material having a melting point or a softening point higher than the melting point of the low melting point metal,
The first particles are:
When the first circuit electrode and the second circuit electrode are connected, the insulating layer is softened and partially removed by heating and pressurizing during circuit connection, and the core exposed from the insulating layer And the first and second circuit electrodes are metal-bonded to achieve conduction between the first circuit electrode and the second circuit electrode,
The second particles are
A circuit connection material, which functions as a spacer under the connection conditions of the first and second circuit electrodes when the first circuit electrode and the second circuit electrode are connected.   The content ratio of the first particles with respect to the total mass is 1 to 10 mass%, and the content ratio of the second particles with respect to the total mass is 1 to 10 mass%. The circuit connection material described.   The circuit connection material according to claim 1, wherein the circuit connection material is formed in a film shape. A circuit connection material according to any one of claims 1 to 3, a first circuit electrode, and a second circuit electrode,
The circuit member connection structure, wherein the first circuit electrode and the second circuit electrode are electrically connected to each other via the circuit connection material.

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