JP2013055058A - Circuit connection material and connection structure of circuit member - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a circuit connection material and a connection structure of a circuit member which achieve good electrical connection between facing circuit electrodes even if surfaces of the circuit electrodes are flat and sufficiently improve the long term reliability of electric characteristics between the circuit electrodes.SOLUTION: A circuit connection material is disposed between a first circuit member 30 having a first circuit electrode 32 and a second circuit member 40, which faces the first circuit member 30 and has a second circuit electrode 42, and establishes electrical continuity between the first circuit electrode 32 and the second circuit electrode 42. The circuit connection material includes: an adhesive composition and a conductive particle 12 having a diameter ranging from 0.5 μm to 4 μm. The outermost layer 22 of the conductive particle 12 is made of Ni or Ni alloy which has Vickers hardness of 300 Hv or higher. A part of the outermost layer 22 protrudes outwardly to form a protruding part 14, and a specific relationship is established between the diameter and the hardness of the conductive particle 12.

Description

  The present invention relates to a circuit connection material and a circuit member connection structure.

  For connection between circuit members such as connection between liquid crystal display and tape carrier package (TCP), connection between flexible printed circuit (FPC) and TCP, or connection between FPC and printed wiring board A circuit connection material (for example, anisotropic conductive adhesive) in which conductive particles are dispersed in an adhesive is used. Recently, when a semiconductor silicon chip is mounted on a substrate, so-called flip chip mounting, in which the semiconductor silicon chip is directly mounted on the substrate face down without using a wire bond to connect circuit members, is performed. It has been broken. Also in this flip chip mounting, a circuit connection material such as an anisotropic conductive adhesive is used for connection between circuit members (see, for example, Patent Documents 1 to 5).

JP 59-120436 A JP-A-60-191228 JP-A-1-251787 JP-A-7-90237 JP 2001-189171 A JP 2005-166438 A

  By the way, in recent years, with the miniaturization and thinning of electronic devices, the density of circuits formed on circuit members has progressed, and the distance between adjacent electrodes and the width of electrodes tend to be very narrow. A circuit electrode is formed by forming a base metal of the circuit on the entire surface of the substrate, applying and curing a resist on the circuit electrode portion, and etching the other portions with acid or base. In the case of an integrated circuit, if the metal unevenness formed on the entire surface of the substrate is large, the etching time differs between the concave portion and the convex portion, so that precise etching cannot be performed, and a short circuit or disconnection between adjacent circuits occurs. There was a problem. For this reason, it has been desired that the metal (circuit electrode surface) of the high-density circuit has small unevenness, that is, the electrode surface is flat.

  However, when circuit electrodes with flat surfaces are made to face each other and a conventional circuit connection material is interposed between them, the conductive particles contained in the circuit connection material and the surface of the flat circuit electrode are between them. In other words, the adhesive resin remains and the conductive particles and the circuit electrodes are not sufficiently in contact with each other, so that sufficient electrical connection and long-term reliability of the electrical characteristics cannot be secured between the circuit electrodes.

  Therefore, in order to ensure the long-term reliability of the electrical connection and electrical characteristics between the circuit electrodes, a plurality of protrusions are provided on the surface of the conductive particles, and the adhesive composition between the conductive particles and the circuit electrodes at the time of circuit connection A method has been devised in which the conductive particles are brought into contact with the circuit electrodes by penetrating through the protrusions (see Patent Document 6). However, even if this method is used, depending on the specifications (material, etc.) of the circuit electrodes, there are cases where the effect of ensuring the electrical connection between the circuit electrodes and the long-term reliability of the electrical characteristics is small.

  The present invention has been made in view of the above circumstances, and even if the surface of the circuit electrode is flat, it is possible to achieve good electrical connection between the facing circuit electrodes and to achieve a long-term electrical property between the circuit electrodes. It is an object of the present invention to provide a circuit connection material and a circuit member connection structure that can sufficiently enhance reliability.

  As a result of diligent research to solve the above problems, the present inventor has found that the long-term reliability of the electrical connection between the circuit electrodes and the electrical characteristics cannot be sufficiently secured with the conventional circuit connection material. I found out that it is in the material. That is, since the outermost layer of the conductive particles included in the conventional circuit connection material is made of Au, which is a relatively soft metal, an adhesive composition between the conductive particles and the circuit electrode is formed on the surface of the conductive particles. The present inventor has found that even if the Au protrusion is penetrated, the Au protrusion is deformed and is difficult to bite into the circuit electrode. Furthermore, the present inventor changed the material of the outermost layer of the conductive particles to a metal harder than Au, and further optimized the hardness of the conductive particles according to the particle size of the conductive particles, thereby electrically connecting the circuit electrodes. It has been found that the long-term reliability of connection and electrical characteristics is improved, and the present invention has been completed.

The circuit connection material of the present invention is interposed between a first circuit member having a first circuit electrode and a second circuit member having a second circuit electrode facing the first circuit member. In the circuit connection material for electrically connecting the first circuit electrode and the second circuit electrode, the adhesive composition and conductive particles having a diameter of 0.5 to 7 μm are contained. The outermost layer is made of a metal having a Bickers hardness of 300 Hv or more, and a part of the outermost layer protrudes outward to form a protrusion. When the diameter of the conductive particles is 5 μm or more and 7 μm or less, the hardness of the conductive particles is 200 to 1200 kgf / mm ² , when the diameter of the conductive particles is 4 μm or more and less than 5 μm, the hardness of the conductive particles is 300 to 1300 kgf / mm ² , and when the diameter of the conductive particles is 3 μm or more and less than 4 μm, Hardness is 400-1400kgf / a mm ^2, when the diameter of the conductive particles is less than 3μm than 2 [mu] m, the hardness of the conductive particles are 450~1700kgf / mm ^2, when the diameter of the conductive particles is less than 2 [mu] m or more 0.5 [mu] m, the hardness of the conductive particles 500 to 2000 kgf / mm ² .

In addition, although the range of the hardness of the electroconductive particle in this invention is defined by the said unit, if converted into SI unit which is mainstream now, 200-1200 kgf / mm < ² > will be a value of 1.961-1.768 GPa. , 300~1300kgf / mm ² is the value of 2.942~12.749GPa, 400~1400kgf / mm ² is the value of 3.923~13.729GPa, 450~1700kgf / mm ² is 4.413 to 16. A value of 671 GPa is obtained, and 500 to 2000 kgf / mm ² is a value of 4.903 to 19.613 GPa.

In the present invention, in order to optimize the hardness of the conductive particles corresponding to the diameter of the conductive particles, and to project a part of the outermost layer made of a metal having a Bickers hardness of 300 Hv or more to the outside, to form a protrusion, When the first and second circuit members are pressure-bonded, the protrusions deeply bite into the first and second circuit electrodes, and the conductive particles are appropriately flattened. As a result, the contact area between the circuit and the individual conductive particles is increased, and the circuit members are bonded together in a state where the conductive particles and the first and second circuit electrodes are securely in contact with each other. A state in which the resistance is low is maintained for a long time.
That is, it is possible to achieve good electrical connection between the circuit electrodes facing each other and sufficiently increase the long-term reliability of the electrical characteristics between the circuit electrodes. The term “flattened” of the conductive particles means that the conductive particles are crushed in a direction substantially perpendicular to the circuit electrode surface and distorted in a substantially parallel direction.

  In the circuit connection material of the present invention, the height of the protrusion is 50 to 500 nm, a part of the outermost layer protrudes outward to form a plurality of protrusions, and the distance between adjacent protrusions is 1000 nm. The following is preferable.

  When the height of the protrusion is less than 50 nm, the connection resistance value tends to increase after the high temperature and high humidity treatment of the connection structure of the first circuit member and the second circuit member using the circuit connection material. If it is larger than 500 nm, the contact area between the conductive particles and the first and second circuit electrodes becomes small, so that the connection resistance value tends to increase.

  In the circuit connection material of the present invention, the outermost layer is preferably made of Ni.

  By configuring the outermost layer with Ni, which is a metal having a Bickers hardness of 300 Hv or more, the effect of the present invention can be easily obtained.

  The circuit connecting material of the present invention is preferably in the form of a film.

  A circuit member connection structure (connection structure) according to the present invention includes a circuit connection material according to the present invention interposed between a first circuit member and a second circuit member. The second circuit electrode is electrically connected.

  In the circuit member connection structure using the circuit connection material of the present invention, a state in which the connection resistance between the first and second electrodes is small is maintained for a long period of time. That is, it is possible to achieve good electrical connection between the circuit electrodes facing each other and sufficiently increase the long-term reliability of the electrical characteristics between the circuit electrodes.

  In the circuit member connection structure of the present invention, the first or second circuit electrode is preferably indium-tin oxide or indium-zinc oxide.

  In the present invention, when the circuit electrode is made of indium-tin oxide or indium-zinc oxide, the effect of improving the electrical connection between the circuit electrodes and the long-term reliability of the electrical characteristics becomes significant.

In the circuit member connection structure of the present invention, the thickness of the first or second circuit electrode is preferably 50 nm or more.

  When the thickness of the first or second circuit electrode is less than 50 nm, the protrusion on the surface of the conductive particles contained in the circuit connection material penetrates the first or second circuit electrode when the circuit members are pressed together. There is a risk of contact with the circuit member, and the contact area between the first or second circuit electrode and the conductive particles tends to decrease and the connection resistance tends to increase.

  According to the circuit connection material and the circuit member connection structure of the present invention, even if the surface of the circuit electrode is flat, it is possible to achieve good electrical connection between the facing circuit electrodes and to improve the electrical characteristics between the circuit electrodes. Long-term reliability can be sufficiently increased.

It is a schematic sectional drawing which shows suitable one Embodiment of the connection structure of the circuit member which concerns on this invention. FIG. 2A and FIG. 2B are schematic cross-sectional views of conductive particles in a preferred embodiment of the circuit connection material according to the present invention.

  Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. In the description of the drawings, the same elements are denoted by the same reference numerals, and redundant description is omitted. For the convenience of illustration, the dimensional ratios in the drawings do not necessarily match those described.

[Circuit connection material]
Although the circuit connection material of this invention contains an adhesive composition and electroconductive particle, forms, such as a paste form and a film form, are mentioned as the form. Below, the film-form circuit connection material which is one Embodiment of the circuit connection material of this invention is demonstrated in detail. The film-like circuit connection material is formed by forming the circuit connection material into a film shape. For example, the circuit connection material is applied on a support (PET (polyethylene terephthalate) film or the like) using a coating apparatus. It can be prepared by drying with hot air for a predetermined time.

  The film-like circuit connecting material contains conductive particles 12 and an adhesive composition, and the adhesive composition has adhesiveness and is cured by a curing process (see FIGS. 1 and 2). As a result, the film-like circuit connecting material is interposed between the first and second circuit members 30 and 40, and the first circuit electrode 32 included in the first circuit member 30 and the second circuit member 40. Is electrically connected to the second circuit electrode 42 of the.

  Since the film-like circuit connection material is film-like and easy to handle, when connecting the first circuit member 30 and the second circuit member 40, they can be easily interposed between them. The connection work between the first circuit member 30 and the second circuit member 40 can be easily performed.

(Conductive particles)
As shown in FIG. 2A, the conductive particles 12 contained in the film-like circuit connecting material are generally composed of a core body 21 made of an organic polymer compound and an outermost layer (metal layer) formed on the surface of the core body 21. 22) is preferable in forming the protrusions on the conductive particles. The core body 21 includes a core portion 21a and a core-side protrusion portion 21b formed on the surface of the core portion 21a. The core body 21 can be formed by adsorbing a plurality of core side projections 21b having a smaller diameter than the core part 21a on the surface of the core part 21a. A part of the metal layer 22 protrudes outward to form a plurality of protrusions 14. The metal layer 22 is made of a metal having conductivity and having a Bickers hardness of 300 Hv or more. In the present invention, the diameter of the conductive particles is not less than 0.5 μm and not more than 7 μm. If the diameter is less than 0.5 μm, desirable continuity tends not to be obtained, and if it exceeds 7 μm, a short circuit tends to occur at the time of connection at a location where the distance between electrodes is short, such as for liquid crystal panel applications. The diameter of the conductive particles is the particle size of the entire conductive particles 12 including the protrusions 14 and can be measured by observation with an electron microscope.

When the diameter of the conductive particles is 5 μm or more and 7 μm or less, the hardness of the conductive particles is 200 to 1200 kgf / mm ² (1.961 to 11.768 GPa). When the diameter of the conductive particles is 4 μm or more and less than 5 μm, the hardness of the conductive particles is 300 to 1300 kgf / mm ² (2.942 to 12.749 GPa). When the diameter of the conductive particles is 3 μm or more and less than 4 μm, the hardness of the conductive particles is 400 to 1400 kgf / mm ² (3.923 to 13.729 GPa). When the diameter of the conductive particles is 2 μm or more and less than 3 μm, the hardness of the conductive particles is 450 to 1700 kgf / mm ² (4.413 to 16.671 GPa). When the diameter of the conductive particles is 0.5 μm or more and less than 2 μm, the hardness of the conductive particles is 500 to 2000 kgf / mm ² (4.903 to 19.613 GPa).

  In the present embodiment, the hardness of the conductive particles 12 is optimized as described above corresponding to the diameter of the conductive particles 12, and a part of the outermost layer made of a metal having a Bickers hardness of 300 Hv or more is projected outward. Only when the protrusions are formed can a good electrical connection between the opposing circuit electrodes 32 and 42 be achieved, and the long-term reliability of the electrical characteristics between the circuit electrodes 32 and 42 can be sufficiently enhanced. Below, the relationship between the diameter, the hardness, and the protrusion of the conductive particles 12, the electrical connection between the circuit electrodes 32 and 42, and the long-term reliability of the electrical characteristics will be described.

  When the circuit electrodes 32 and 42 facing each other are electrically connected with a circuit connecting material, the connection resistance is determined by the number of the conductive particles 12 existing between the circuit electrodes 32 and 42 and the circuit electrodes and the individual conductive particles 12. Depending on the contact area, the contact area varies depending on the flatness of the conductive particles 12. That is, the larger the number of conductive particles 12 present between the circuit electrodes 32 and 42, the lower the connection resistance, and the greater the flatness of the conductive particles 12, the wider the contact area between the circuit electrodes 32 and 42 and the conductive particles 12. , The connection resistance is lowered.

  The number of the conductive particles 12 existing between the circuit electrodes 32 and 42 increases as the number of the conductive particles 12 included in the unit volume of the circuit connection material increases. The number of conductive particles 12 included in the unit volume of the circuit connecting material increases as the diameter of the conductive particles 12 decreases. Further, the number of the conductive particles 12 that are in contact with the circuit electrodes 32 and 42 and contribute to the electrical connection between the circuit electrodes 32 and 42 is limited by the area of the circuit electrodes 32 and 42. And the contact area between the conductive particles 12 and the individual conductive particles 12 are smaller. The contact area between the circuit electrodes 32 and 42 and the conductive particles 12 becomes narrower as the flatness of the conductive particles 13 is smaller. The flatness of the conductive particles 12 depends on the hardness of the conductive particles 12, and decreases as the hardness of the conductive particles 12 increases.

  Thus, when the diameter of the conductive particles 12 is small, the connection resistance between the circuit members 30 and 40 tends to decrease as the hardness of the conductive particles 12 increases.

  On the other hand, when the diameter of the conductive particles 12 is large, the number of the conductive particles 12 existing between the circuit electrodes 32 and 42 is reduced. Therefore, in order to reduce the connection resistance between the circuit members 30 and 40, the circuit electrode 32. , 42 and the individual conductive particles 12 need to be widened. The contact area between the circuit electrodes 32 and 42 and the individual conductive particles 12 increases as the flatness of the conductive particles 12 increases. The flatness of the conductive particles 12 increases as the hardness of the conductive particles decreases.

  Thus, when the particle diameter of the conductive particles 12 is large, the connection resistance between the circuit members 30 and 40 tends to decrease as the hardness of the conductive particles 12 decreases.

  As described above, the hardness of the conductive particles that provide a good connection resistance between the circuit members 30 and 40 varies depending on the diameter of the conductive particles 12. Therefore, in this embodiment, by using the conductive particles 12 in which the diameter and hardness of the conductive particles 12 satisfy the above relationship, a good connection resistance can be obtained even after a reliability test such as a high-temperature and high-humidity test. When the hardness of the conductive particles 12 is below the lower limit value of the hardness corresponding to the diameter of each conductive particle, the restoring force of the conductive particles 12 is weak, and the connection resistance tends to increase after a reliability test such as a high-temperature and high-humidity test. is there. In addition, when the hardness of the conductive particles 12 exceeds the upper limit value of the hardness corresponding to the diameter of each conductive particle, the conductive particles 12 do not have a sufficiently flat shape. The connection resistance tends to increase after a reliability test such as a high-temperature and high-humidity test due to a decrease in the contact area.

  Further, since the metal layer 22 made of metal having a Bickus hardness of 300 Hv or higher is harder than the outermost layer made of conventional Au, the protruding portion 14 protruding from the metal layer 22 has a circuit electrode 32, Since it becomes easy to bite into 42, the contact area between the conductive particles 12 and the circuit electrodes 32 and 42 increases. Then, by curing the circuit connecting material, the conductive particles 12 and the circuit electrodes 32 and 42 are in contact with each other, and the contact area between the conductive particles 12 and the circuit electrodes 32 and 42 is sufficiently secured for a long time. Held over.

  Examples of the organic polymer compound constituting the core portion 21a of the core body 21 include acrylic resin, styrene resin, benzoguanamine resin, silicone resin, polybutadiene resin, or a copolymer thereof. May be. In addition, it is preferable that the average particle diameter of the core part 21a of the core 21 is not less than 0.5 and not more than 7 μm. Examples of the organic polymer compound constituting the core-side protruding portion 21b of the core body 21 include an acrylic resin, a styrene resin, a benzoguanamine resin, a silicone resin, a polybutadiene resin, or a copolymer thereof. May be used. The organic polymer compound that constitutes the core-side protruding portion 21b may be the same as or different from the organic polymer compound that constitutes the core portion 21a. In addition, it is preferable that the average particle diameter of the nucleus side projection part 21b is 50-500 nm.

  The hardness of the conductive particles 12 is almost governed by the hardness of the core 21 of the conductive particles 12. The hardness of the conductive particles 12 depends on the structure of the molecules constituting the core 21, the distance between the crosslinking points, and the degree of crosslinking. Since benzoguanamine and the like have a rigid structure in the molecule and the distance between the crosslinking points is short, the harder conductive particles 12 are obtained as the proportion of benzoguanamine and the like occupying in all the molecules constituting the core 21 increases. Hard conductive particles 12 can be obtained by increasing the degree of crosslinking of the core 21 of the conductive particles 12. Since acrylic ester, diallyl phthalate and the like have a long distance between cross-linking points, the softer conductive particles 12 are obtained as the proportion of acrylic ester, diallyl phthalate, etc. occupying all the molecules constituting the core 21 increases. Soft conductive particles 12 can be obtained by reducing the degree of crosslinking.

  The metal layer 22 is made of a metal having a Bickers hardness of 300 Hv or more, such as Cu, Ni, a Ni alloy, Ag, an Ag alloy, or the like, and particularly preferably made of Ni. The metal layer 22 can be formed, for example, by plating a metal having a Bickus hardness of 300 Hv or more on the core 21 using an electroless plating method.

  The thickness of the metal layer 22 (plating thickness) is preferably 50 to 170 nm, and more preferably 50 to 150 nm. By setting the thickness of the metal layer 22 in such a range, the connection resistance between the circuit electrodes 32 and 42 can be further reduced. If the thickness of the metal layer 22 is less than 50 nm, plating defects tend to occur and the connection resistance tends to increase. If the thickness exceeds 170 nm, condensation occurs between the conductive particles and a short circuit occurs between adjacent circuit electrodes. There is. The thickness of the metal layer 22 is the average thickness of the metal layer 22 excluding the protrusions 14.

  The height H of the protrusion 14 is preferably 50 to 500 nm, and more preferably 75 to 300 nm. When the height of the protrusion is less than 50 nm, the connection resistance value tends to increase after the high-temperature and high-humidity treatment. When the height is greater than 500 nm, the contact area between the conductive particles 12 and the circuit electrodes 32 and 42 is small. The connection resistance value tends to increase.

  The distance S between the adjacent protrusions 14 is preferably 1000 nm or less, and more preferably 500 nm or less. Further, the distance S between the adjacent protrusions 14 is sufficient to bring the conductive particles 12 into contact with the circuit electrodes 32 and 42 without the adhesive composition entering between the conductive particles 12 and the circuit electrodes 32 and 42. Is preferably at least 50 nm or more.

  The height H of the protrusions 14 of the conductive particles 12 and the distance S between the adjacent protrusions 14 can be measured with an electron microscope. Specifically, the magnification of the electron microscope is adjusted so that 10 or more and less than 50 conductive particles enter the visual field, and the height of the protrusions and the distance between adjacent protrusions are selected for the three conductive particles selected arbitrarily. The distance is measured at five points, and the average value of the obtained 15 data is obtained.

  The blending amount of the conductive particles 12 in the film-like circuit connecting material is preferably 0.1 to 30 parts by volume with respect to 100 parts by volume of the adhesive composition, and the blending amount can be properly used depending on the application. From the viewpoint of preventing short circuit of the circuit electrodes 32 and 42 due to excessive conductive particles 12, the blending amount of the conductive particles 12 is more preferably 0.1 to 10 parts by volume.

  In addition, as shown in FIG.2 (b), as for the electrically-conductive particle 12, the nucleus 21 may be comprised only in the core part 21a. The conductive particles 12 can be obtained by metal plating the surface of the core 21 and forming a metal layer 22 on the surface of the core 21. Further, the protrusion 14 can be formed by changing the thickness of the metal layer 22 by changing the plating conditions during metal plating. The plating conditions can be changed, for example, by making the plating solution concentration non-uniform by adding a plating solution having a higher concentration to the plating solution used first.

(Adhesive composition)
The adhesive composition contained in the film-like circuit connecting material includes a composition containing an epoxy resin and a latent curing agent for the epoxy resin (hereinafter referred to as “first composition”), a radical polymerizable substance, A composition containing a curing agent that generates free radicals upon heating (hereinafter, “second composition”), or a mixed composition of the first composition and the second composition is preferable.

  The epoxy resin contained in the first composition is 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 novolac type epoxy resin, bisphenol. Examples thereof include F novolac type epoxy resins, alicyclic 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. Two or more of these epoxy resins may be used in combination.

  The latent curing agent contained in the first composition is not particularly limited as long as it can cure the epoxy resin. Examples of such latent curing agents include anionic polymerizable catalyst-type curing agents and cationic polymerizable agents. Catalyst-type curing agents, polyaddition-type curing agents, and the like. These can be used alone or as a mixture of two or more. Of these, anionic or cationic polymerizable catalyst-type curing agents are preferred because they are excellent in rapid curability and do not require chemical equivalent considerations.

  Examples of the anionic or cationic polymerizable catalyst-type curing agent include imidazole, hydrazide, boron trifluoride-amine complex, sulfonium salt, amine imide, diaminomaleonitrile, melamine and derivatives thereof, polyamine salt, dicyandiamide and the like. These modifications can also be used. Examples of the polyaddition type curing agent include polyamines, polymercaptans, polyphenols, and acid anhydrides.

  When a tertiary amine or imidazole is blended as an anionic polymerization type catalyst curing agent, the epoxy resin is cured by heating at a medium temperature of about 160 ° C. to 200 ° C. for several tens of seconds to several hours. For this reason, the pot life is relatively long, which is preferable. As the cationic polymerization type catalyst-type curing agent, for example, a photosensitive onium salt (an aromatic diazonium salt, an aromatic sulfonium salt or the like is mainly used) that cures an epoxy resin by irradiation with energy rays is preferable. In addition to irradiation with energy rays, there are aliphatic sulfonium salts and the like that are activated by heating to cure the epoxy resin. This type of curing agent is preferable because it has a feature of fast curing.

  When these latent hardeners are coated with polymer materials such as polyurethane or polyester, metal thin films such as nickel or copper, and inorganic materials such as calcium silicate, the pot life is extended. This is preferable because it is possible.

  The radically polymerizable substance contained in the second composition is a substance having a functional group that is polymerized by radicals. Examples of such radically polymerizable substances include acrylate (including corresponding methacrylates; the same shall apply hereinafter) compounds, acryloxy (including corresponding methacryloxy; the same shall apply hereinafter) compounds, maleimide compounds, citraconic imide resins, nadiimide resins, and the like. It is done. The radically polymerizable substance may be used in a monomer or oligomer state, and the monomer and oligomer may be used in combination. Specific examples of the acrylate compound include methyl acrylate, ethyl acrylate, isopropyl acrylate, isobutyl acrylate, ethylene glycol diacrylate, diethylene glycol diacrylate, trimethylolpropane triacrylate, tetramethylolmethane tetraacrylate, 2-hydroxy-1,3- Diacryloxypropane, 2,2-bis [4- (acryloxymethoxy) phenyl] propane, 2,2-bis [4- (acryloxypolyethoxy) phenyl] propane, dicyclopentenyl acrylate, tricyclodecanyl acrylate , Tris (acryloyloxyethyl) isocyanurate, urethane acrylate and the like. These can be used alone or in admixture of two or more. Moreover, you may use polymerization inhibitors, such as a hydroquinone and methyl ether hydroquinones, suitably if needed. Furthermore, from the viewpoint of improving heat resistance, the acrylate compound preferably has at least one substituent selected from the group consisting of a dicyclopentenyl group, a tricyclodecanyl group, and a triazine ring.

  The maleimide compound contains at least two maleimide groups in the molecule. Examples of such maleimide compounds include 1-methyl-2,4-bismaleimide benzene, N, N′-m-phenylene bismaleimide, N, N′-p-phenylene bismaleimide, N, N′-m. -Toluylene bismaleimide, 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′-3,3′-diphenylsulfone bismaleimide, N, N′-4,4-diphenyl ether bismale 2,2-bis (4- (4-maleimidophenoxy) phenyl) propane, 2,2-bis (3-s-butyl-4,8- (4-maleimidophenoxy) phenyl) propane, 1,1- Bis (4- (4-maleimidophenoxy) phenyl) decane, 4,4′-cyclohexylidene-bis (1- (4-maleimidophenoxy) -2-cyclohexylbenzene, 2,2-bis (4- (4- And maleimidephenoxy) phenyl) hexafluoropropane, which can be used alone or in admixture of two or more.

  The citraconic imide resin is obtained by polymerizing a citraconic imide compound having at least one citraconic imide group in the molecule. Examples of the citraconimide compound 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 ) Biscitraconimide, N, N′-4,4- (3,3-diethyldiphenylmethane) biscitraconimide, N, N′-4,4-diphenylmethane biscitraconimide, N, N′-4,4-diphenyl Propane biscitraconimide, N, N'-4,4-diphenyl ether biscitraconimide, N, N'- , 4-Diphenylsulfonebiscitraconimide, 2,2-bis (4- (4-citraconimidophenoxy) phenyl) propane, 2,2-bis (3-s-butyl-3,4- (4-citraconimidephenoxy) ) Phenyl) propane, 1,1-bis (4- (4-citraconimidophenoxy) phenyl) decane, 4,4′-cyclohexylidene-bis (1- (4-citraconimidophenoxy) phenoxy) -2-cyclohexyl Examples include benzene and 2,2-bis (4- (4-citraconimidophenoxy) phenyl) hexafluoropropane. These can be used alone or in admixture of two or more.

  The nadiimide resin is obtained by polymerizing a nadiimide compound having at least one nadiimide group in the molecule. 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-diphenylmethane bisnadiimide, N, N'-4,4-diphenylpropane bisnadiimide, N, N'-4,4 -Diphenyl ether bisnadiimide, N, N'-4,4-diphenylsulfone bisnadiimide, 2,2-bis (4- (4-nazii Dophenoxy) 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) hexafluoro Propane is mentioned. These can be used alone or in admixture of two or more.

  Moreover, it is preferable to use together the radical polymerizable substance which has the phosphate ester structure shown by the following general formula (I) with the said radical polymerizable substance. In this case, since the adhesive strength to the surface of an inorganic substance such as metal is improved, it is suitable for bonding the circuit electrodes 32 and 42 to each other.

［上記式中、ｎは１〜３の整数を示す。］

[In the above formula, n represents an integer of 1 to 3. ]

  The radically polymerizable substance having a phosphoric ester structure is obtained by reacting phosphoric anhydride with 2-hydroxyethyl (meth) acrylate. Specific examples of the radical polymerizable substance having a phosphate structure include mono (2-methacryloyloxyethyl) acid phosphate, di (2-methacryloyloxyethyl) acid phosphate, and the like. These can be used alone or in admixture of two or more.

  The blending amount of the radical polymerizable substance having the phosphate ester structure represented by the general formula (I) is 0.01 to 100 parts by mass with respect to a total of 100 parts by mass of the radical polymerizable substance and the film forming material to be blended as necessary. It is preferable that it is 50 mass parts, and 0.5-5 mass parts is more preferable.

  The radical polymerizable substance can be used in combination with allyl acrylate. In this case, it is preferable that the compounding quantity of allyl acrylate is 0.1-10 mass parts with respect to 100 mass parts in total of a radically polymerizable substance and the film formation material mix | blended if necessary, 0.5 -5 mass parts is more preferable.

  The hardening | curing agent which generate | occur | produces a free radical by heating which a 2nd composition contains is a hardening | curing agent which decomposes | disassembles by heating and generate | occur | produces a free radical. Examples of such curing agents include peroxide compounds and azo compounds. Such a curing agent is appropriately selected depending on the intended connection temperature, connection time, pot life, and the like. From the viewpoint of high reactivity and improvement in pot life, organic peroxides having a half-life of 10 hours at a temperature of 40 ° C. or more and a half-life of 1 minute at a temperature of 180 ° C. or less are preferred. An organic peroxide having a temperature of 60 ° C. or higher and a half-life of 1 minute is 170 ° C. or lower is more preferable.

  When the connection time is 25 seconds or less, the amount of the curing agent is 2 to 10 parts by mass with respect to 100 parts by mass in total of the radical polymerizable substance and the film-forming material to be blended as necessary. It is preferably 4 to 8 parts by mass. Thereby, sufficient reaction rate can be obtained. In addition, the compounding quantity of the hardening | curing agent in the case where connection time is not limited may be 0.05-20 mass parts with respect to a total of 100 mass parts of a radically polymerizable substance and the film formation material mix | blended as needed. Preferably, it is 0.1-10 mass parts.

  Specific examples of curing agents that generate free radicals upon heating contained in the second composition are diacyl peroxide, peroxydicarbonate, peroxyester peroxyketal, dialkyl peroxide, hydroperoxide, silyl peroxide. Etc. Further, from the viewpoint of suppressing the corrosion of the circuit electrodes 32 and 42, a curing agent having a concentration of contained chlorine ions or organic acids of 5000 ppm or less is preferable, and a curing agent with less organic acid generated after thermal decomposition is more preferable. preferable. Specific examples of such curing agents include peroxyesters, dialkyl peroxides, hydroperoxides, silyl peroxides, and the like, and curing agents selected from peroxyesters that provide high reactivity are more preferable. In addition, the said hardening | curing agent can be mixed and used suitably.

  Peroxyesters include cumylperoxyneodecanoate, 1,1,3,3-tetramethylbutylperoxyneodecanoate, 1-cyclohexyl-1-methylethylperoxynoedecanoate, and t-hexyl. Peroxyneodecanodate, t-butyl peroxypivalate, 1,1,3,3-tetramethylbutylperoxy 2-ethylhexanate, 2,5-dimethyl-2,5-di (2-ethyl) Hexanoylperoxy) hexane, 1-cyclohexyl-1-methylethylperoxy-2-ethylhexanate, t-hexylperoxy-2-ethylhexanate, t-butylperoxy-2-ethylhexanate T-butylperoxyisobutyrate, 1,1-bis (t-butylperoxy) cyclohexane, t Hexylperoxyisopropyl monocarbonate, t-butylperoxy-3,5,5-trimethylhexanonate, t-butylperoxylaurate, 2,5-dimethyl-2,5-di (m-toluoylperoxy ) Hexane, t-butyl peroxyisopropyl monocarbonate, t-butyl peroxy-2-ethylhexyl monocarbonate, t-hexyl peroxybenzoate, t-butyl peroxyacetate 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-butylcumi. Examples include ruperoxide.

  Examples of the hydroperoxide include diisopropylbenzene hydroperoxide and cumene hydroperoxide.

  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.

  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.

  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 curing agents can be used alone or in admixture of two or more, and may be used by mixing a decomposition accelerator, an inhibitor and the like. Further, these curing agents may be coated with a polyurethane-based or polyester-based polymer substance to form microcapsules. A microencapsulated curing agent is preferred because the pot life is extended.

  You may add and use a film forming material for the film-form circuit connection material of this embodiment as needed. The film-forming material is a material that solidifies a liquid material and forms a composition composition into a film shape to facilitate the handling of the film and impart mechanical properties that do not easily tear, break, or stick. Yes, it can be handled as a film in a normal state (normal temperature and normal pressure). Examples of the film forming material include phenoxy resin, polyvinyl formal resin, polystyrene resin, polyvinyl butyral resin, polyester resin, polyamide resin, xylene resin, polyurethane resin and the like. Among these, a phenoxy resin is preferable because of excellent adhesiveness, compatibility, heat resistance, and mechanical strength.

  A phenoxy resin is a resin obtained by reacting a bifunctional phenol and epihalohydrin until they are polymerized or by polyaddition of a bifunctional epoxy resin and a bifunctional phenol. The phenoxy resin, for example, reacts 1 mol of a bifunctional phenol with 0.985 to 1.015 mol of epihalohydrin in a non-reactive solvent at a temperature of 40 to 120 ° C. in the presence of a catalyst such as an alkali metal hydroxide. Can be obtained. Moreover, as a phenoxy resin, especially from the viewpoint of the mechanical characteristics and thermal characteristics of the resin, the mixing equivalent ratio of the bifunctional epoxy resin and the bifunctional phenols is epoxy group / phenol hydroxyl group = 1 / 0.9- 1/1, organic amides, ethers, ketones, lactones, alcohols, etc. having a boiling point of 120 ° C. or higher in the presence of catalysts such as alkali metal compounds, organophosphorus compounds, cyclic amine compounds, etc. What was obtained by heating to 50-200 degreeC on the conditions whose reaction solid content is 50 mass% or less in a solvent was made to carry out a polyaddition reaction.

  Examples of the bifunctional epoxy resin include bisphenol A type epoxy resin, bisphenol F type epoxy resin, bisphenol AD type epoxy resin, bisphenol S type epoxy resin, biphenyl diglycidyl ether, and methyl-substituted biphenyl diglycidyl ether. Bifunctional phenols have two phenolic hydroxyl groups. Examples of the bifunctional phenols include hydroquinones, bisphenol A, bisphenol F, bisphenol AD, bisphenol S, bisphenol fluorene, methyl-substituted bisphenol fluorene, bisphenols such as dihydroxybiphenyl and methyl-substituted dihydroxybiphenyl. The phenoxy resin may be modified (for example, epoxy-modified) with a radical polymerizable functional group or other reactive compound. You may use a phenoxy resin individually or in mixture of 2 or more types.

  The film-like circuit connecting material of this embodiment may further contain a polymer or copolymer containing at least one of acrylic acid, acrylic acid ester, methacrylic acid ester and acrylonitrile as a monomer component. Here, since it is excellent in stress relaxation, it is preferable to use together the copolymer type acrylic rubber containing glycidyl acrylate and glycidyl methacrylate containing a glycidyl ether group. The weight average molecular weight of these acrylic rubbers is preferably 200,000 or more from the viewpoint of increasing the cohesive strength of the adhesive.

  The film-like circuit connecting material of the present embodiment further comprises rubber fine particles, fillers, softeners, accelerators, anti-aging agents, colorants, flame retardants, thixotropic agents, coupling agents, phenol resins, melamine resins. , Isocyanates and the like can also be contained.

  The rubber fine particles have an average particle size of not more than twice the average particle size of the conductive particles 12 to be blended, and the storage elastic modulus at room temperature (25 ° C.) at the room temperature of the conductive particles 12 and the adhesive composition. What is necessary is just to be 1/2 or less of storage elastic modulus. In particular, it is preferable that the fine particles whose material of the rubber fine particles is silicone, acrylic emulsion, SBR, NBR, or polybutadiene rubber are used alone or in admixture of two or more. These three-dimensionally crosslinked rubber fine particles have excellent solvent resistance and are easily dispersed in the adhesive composition.

  The circuit connecting material may contain a filler. Thereby, the connection reliability of the electrical characteristics between the circuit electrodes 32 and 42, etc. improve. The filler can be used if its maximum diameter is ½ or less of the particle diameter of the conductive particles 12. Moreover, when using together the particle | grains which do not have electroconductivity, if it is below the diameter of the particle | grains which do not have electroconductivity, it can be used. It is preferable that the compounding quantity of a filler is 5-60 volume parts with respect to 100 volume parts of adhesive compositions. If the blending amount exceeds 60 parts by volume, the effect of improving the connection reliability tends to be saturated, and if it is less than 5 parts by volume, the effect of adding the filler tends to be insufficient.

  As said coupling agent, the compound containing a vinyl group, an acryl group, an epoxy group, or an isocyanate group is preferable since adhesiveness improves.

[Circuit member connection structure]
An embodiment of a circuit member connection structure according to the present invention will be described in detail. As shown in FIG. 1, the circuit member connection structure 1 of this embodiment includes a first circuit member 30 and a second circuit member 40 that face each other. Between the 1st circuit member 30 and the 2nd circuit member 40, the circuit connection member 10 which connects these is provided. The circuit connecting member 10 is formed by curing the film-like circuit connecting material of the present embodiment described above.

  The first circuit member 30 includes a first circuit board 31 and a first circuit electrode 32 formed on the main surface 31 a of the circuit board 31. The second circuit member 40 includes a circuit board 41 and a second circuit electrode 42 formed on the main surface 41 a of the second circuit board 41. The first circuit electrode 32 formed on the main surface 31a of the first circuit board 31 and the second circuit electrode 42 formed on the main surface 41a of the second circuit board 41 face each other. In the circuit boards 31 and 41, the surfaces of the circuit electrodes 32 and 42 are flat. In the present invention, “the surface of the circuit electrode is flat” means that the unevenness of the surface of the circuit electrode is 20 nm or less.

  The circuit connecting member 10 contains an insulating material 11 and conductive particles 12 formed by curing the adhesive resin composition. In the circuit member connection structure 1, the first circuit electrode 32 and the second circuit electrode 42 facing each other are electrically connected via the conductive particles 12 contained in the circuit connection member 10. That is, the conductive particles 12 are in direct contact with both the first circuit electrode 32 and the second circuit electrode 42. Specifically, the protrusion 14 formed on the metal layer 22 (outermost layer) of the conductive particles 12 penetrates the insulating substance 11 and contacts both the first circuit electrode 32 and the second circuit electrode 42. doing. Furthermore, since the protrusion 14 bites into the circuit electrodes 32 and 42, the contact area between the conductive particles 12 and the circuit electrodes 32 and 42 increases. For this reason, the connection resistance between the circuit electrodes 32 and 42 is sufficiently reduced, and a good electrical connection between the circuit electrodes 32 and 42 becomes possible. Therefore, the flow of current between the circuit electrodes 32 and 42 can be made smooth, and the functions of the circuit can be fully exhibited.

  The thickness of the first circuit electrode 32 or the second circuit electrode 42 is preferably 50 nm or more. When the thickness is less than 50 nm, the protrusions 14 on the surface of the conductive particles contained in the circuit connecting material may pass through the circuit electrodes 32 and 42 and come into contact with the circuit boards 31 and 41 when the circuit members are pressed together. In other words, the contact area between the circuit electrodes 32 and 42 and the conductive particles 12 tends to decrease and the connection resistance tends to increase.

  Examples of the material of the circuit electrodes 32 and 42 include Au, Ag, Sn, Pt group metal, indium-tin oxide (ITO), indium-zinc oxide (IZO), Al, and Cr, but ITO or IZO. Is preferred. When the circuit electrodes 32 and 42 are made of ITO or IZO, the effect of improving the electrical connection between the circuit electrodes and the long-term reliability of the electrical characteristics becomes significant. In addition, although the circuit electrodes 32 and 42 are entirely composed of the above substance, only the surface of the circuit electrode may be composed of the above substance.

  The material of the circuit boards 31 and 41 is not particularly limited, but is usually an organic insulating material, glass, or silicon.

  Specific examples of the first circuit member 30 and the second circuit member 40 include chip components such as a semiconductor chip, a resistor chip, and a capacitor chip, and a substrate such as a printed circuit board. These circuit members are usually provided with a large number of circuit electrodes (circuit terminals). In some cases, a single circuit electrode may be provided on the circuit member.

  As the form of the circuit member connection structure 1, there are also a connection structure between an IC chip and a chip mounting substrate and a connection structure between electrical circuits.

The surface area of at least one of the first circuit electrode 32 or the second circuit electrode 42 is 15000 μm ² or less, and the average number of conductive particles between the first circuit electrode 32 and the second circuit electrode 42 is 3 It is preferable that the number is at least. Here, the average number of conductive particles refers to the average value of the number of conductive particles 12 per circuit electrode. In this case, the connection resistance between the circuit electrodes 32 and 42 facing each other can be more sufficiently reduced. Further, when the average number of conductive particles is 6 or more, even better connection resistance can be achieved. This is because the connection resistance between the circuit electrodes 32 and 42 facing each other is sufficiently low. Further, when the average number of conductive particles between the circuit electrodes 32 and 42 is 2 or less, the connection resistance becomes too high, and the electronic circuit tends not to operate normally.

[Method of manufacturing circuit member connection structure]
Next, the manufacturing method of the circuit member connection structure 1 described above will be described. First, the first circuit member 30, the second circuit member 40, and a circuit connection material are prepared.

  A film-like circuit connection material is prepared as a circuit connection material. The thickness of the film-like circuit connecting material is preferably 10 to 50 μm.

  Next, a film-like circuit connecting material is placed on the first circuit member 30. And the 2nd circuit member 40 is mounted on a film-form circuit connection material so that the circuit electrode 32 of the 1st circuit member 30 and the circuit electrode 42 of the 2nd circuit member 40 may overlap. In this way, the film-like circuit connecting material is interposed between the first circuit member 30 and the second circuit member 40. At this time, since the film-like circuit connecting material is film-like and easy to handle, when the first circuit member 30 and the second circuit member 40 are connected, they can be easily interposed between them. The connection work of the 1st circuit member 30 and the 2nd circuit member 40 can be performed easily.

  Next, the film-like circuit connecting material is heated and pressurized through the first circuit member 30 and the second circuit member 40 to perform a curing treatment, and the first circuit member 30 and the second circuit member 40 The circuit connection member 10 is formed between the two. The curing treatment can be performed by a general method, and the method is appropriately selected depending on the adhesive composition.

  In the present embodiment, the outermost layer (metal layer 22) of the conductive particles 12 in the film-like circuit connecting material is made of a metal having a Bickers hardness of 300 Hv or more, and thus constitutes the outermost layer of conventional conductive particles. Harder than Au. Therefore, in the curing process of the film-like circuit connecting material, the protrusions 14 protruding from the metal layer 22 of the conductive particles 12 are the outermost portions of the first or second circuit electrodes 32 and 42 as compared with the case of the conventional conductive particles. The outer layer (electrode surface) bites deeper, and the contact area between the conductive particles 12 and the circuit electrodes 32 and 42 increases. In addition, since the hardness of the conductive particles 12 is optimized according to the diameter of the conductive particles 12, the conductive particles 12 are appropriately flattened, and the contact area between the circuit electrodes 32 and 42 and the conductive particles 12 is increased. The connection resistance between the first and second circuit electrodes 32 and 42 is reduced. Thus, when the adhesive composition in the film-like circuit connecting material is cured in a state where the conductive particles 12 and the first and second circuit electrodes 32 and 42 are in reliable contact with each other, the first circuit member 30 and the second circuit member 30 are formed. A high adhesive strength with the circuit member 40 is realized, and a state in which the connection resistance between the circuit electrodes 32 and 42 is small is maintained for a long period of time.

  That is, in the present embodiment, the hardness of the conductive particles 12 is optimized corresponding to the diameter of the conductive particles 12, and a part of the outermost layer made of a metal having a Bickers hardness of 300 Hv or more protrudes outward to project the protrusions. Only when the first and second circuit electrodes 32 and 42 are formed, the connection resistance between the circuit electrodes 32 and 42 facing each other is sufficiently reduced regardless of whether the surface of the first or second circuit electrodes 32 and 42 is uneven. A good electrical connection between them can be achieved, and the long-term reliability of the electrical characteristics between the circuit electrodes 32 and 42 can be sufficiently enhanced.

  As mentioned above, although preferred embodiment of the film-form circuit connection material which concerns on this invention was described, this invention is not necessarily limited to embodiment mentioned above.

  For example, in the said embodiment, although the connection structure of a circuit member is manufactured using a film-form circuit connection material, you may use the circuit connection material which is not a film form. For example, by applying a solution obtained by dissolving a circuit connecting material in a solvent to one of the first circuit member 30 or the second circuit member 40 and drying, and placing the other circuit member on the dried coated material The circuit connecting material can be interposed between the first and second circuit members 30 and 40.

  In addition, the circuit member connection structure 1 is not provided with an insulating layer, but in the first circuit member 30, a first insulating layer may be formed adjacent to the first circuit electrode 32, In the second circuit member 40, a second insulating layer may be formed adjacent to the second circuit electrode 42. The insulating layer is not particularly limited as long as it is made of an insulating material, but is usually made of an organic insulating material, silicon dioxide or silicon nitride.

(Preparation of conductive particles)
By changing the mixing ratio of tetramethylol methane tetraacrylate, divinyl benzene and styrene monomer, suspension polymerization using benzoyl peroxide as a polymerization initiator and classification, 26 types of nuclei with different particle sizes and hardnesses were obtained. Obtained. Conductive particle Nos. Shown in Table 1 were obtained by subjecting each of the obtained nuclei to electroless Ni plating. 1-26 were obtained. In addition, in the Ni plating process, the conductive particle No. is changed by changing the plating thickness by appropriately adjusting the charging amount of the plating solution, the processing temperature and the processing time. The protrusion part which consists of Ni was formed in the surface (outermost layer) of 1-25. Conductive particle No. No protrusion was formed on 26.

  In addition, Au plating is performed on Ni particles having protrusions to form an Au layer having a plurality of protrusions made of Au. 27 was obtained.

  Further, conductive particle No. Similarly to the case of 1 to 26, the surface of the conductive particles obtained by performing Ni plating on the core is further subjected to substitution plating of Au with a thickness of 25 nm, so that it has a uniform thickness and is made of Au. Conductive particles having outer layers 28 was obtained.

The hardness of the conductive particles is the weight P (unit: MPa or Kgf) when the conductive particles are deformed by 10% from the diameter of the conductive particles using a micro compression tester (manufactured by Shimadzu Corporation), the radius r of the conductive particles (Unit: mm) and displacement Δ during compression (unit: mm) were obtained by the following formula 1.
Hardness of conductive particles = 3 × 2 ^(−1/2) × P × Δ ^(−3/2) × r ^(−1/2) (Formula 1)

  In addition, a plurality of conductive particles No. 1 is placed evenly on a sample table with carbon double-sided tape, and the magnification is adjusted using an electron microscope (S-800, manufactured by Hitachi, Ltd.) so that 10 or more and 50 or less conductive particles enter the field of view. Particle No. The particle size of 1, the height of the protrusions, and the distance between adjacent protrusions were measured. Here, the particle diameter was an average value of the diameters of 10 conductive particles arbitrarily selected. For the height of the protrusion and the distance between adjacent protrusions, the protrusion height and the distance between the protrusions of three arbitrarily selected conductive particles were arbitrarily measured at five points, respectively, and the average of the obtained 15 data Value. In addition, conductive particle No. The particle size of 2 to 28, the height of the protrusions, and the distance between adjacent protrusions are also shown in the conductive particle Nos. Measurement was performed in the same manner as in 1.

(Production of circuit connection material 1)
A phenoxy resin was synthesized from a bisphenol A-type epoxy resin and a phenol compound having a fluorene ring structure in the molecule (4,4 ′-(9-fluorenylidene) -diphenyl), and this resin was combined with toluene / ethyl acetate = It melt | dissolved in the 50/50 mixed solvent, and was set as the solution of 40 mass% of solid content. Next, acrylic rubber (40 parts by weight of butyl acrylate, 30 parts by weight of ethyl acrylate, 30 parts by weight of acrylonitrile, 3 parts by weight of glycidyl methacrylate, and a weight average molecular weight of 800,000) is prepared as a rubber component. It melt | dissolved in the mixed solvent of toluene / ethyl acetate = 50/50 by mass ratio, and it was set as the solution of 15 mass% of solid content. Further, a liquid curing agent containing a microcapsule type latent curing agent (a microencapsulated amine curing agent), a bisphenol F type epoxy resin, and a naphthalene type epoxy resin in a mass ratio of 34:49:17. A contained epoxy resin (epoxy equivalent: 202) was prepared.

  The above materials were blended in a mass ratio of phenoxy resin / acrylic rubber / curing agent-containing epoxy resin = 20 g / 30 g / 50 g to prepare an adhesive composition-containing liquid. With respect to 100 parts by mass of the adhesive composition-containing liquid, the conductive particle No. 5 parts by mass of 1 was dispersed to prepare a circuit connecting material-containing liquid. This circuit connection material-containing liquid is applied to a polyethylene terephthalate (PET) film having a thickness of 50 μm with a surface treated on one side using a coating apparatus, and dried with hot air at 70 ° C. for 3 minutes to have a thickness of 20 μm on the PET film. A film-like circuit connecting material 1 was obtained.

(Production of circuit connection material 2)
50 g of phenoxy resin (trade name PKHC, manufactured by Union Carbide Co., Ltd., average weight molecular weight 5000) is dissolved in a mixed solvent of toluene / ethyl acetate = 50/50 (mass ratio) to obtain a phenoxy resin solution having a solid content of 40% by mass. It was. While stirring 400 parts by mass of polycaprolactone diol having an average weight molecular weight of 800, 131 parts by mass of 2-hydroxypropyl acrylate, 0.5 parts by mass of dibutyltin dilaurate as a catalyst and 1.0 part by mass of hydroquinone monomethyl ether as a polymerization inhibitor Heat to 50 ° C. and mix. Next, 222 parts by mass of isophorone diisocyanate was dropped into this mixed solution, and the mixture was further heated to 80 ° C. while stirring to carry out a urethanization reaction. After confirming that the reaction rate of the isocyanate group was 99% or more, the reaction temperature was lowered to obtain urethane acrylate.

  Next, the phenoxy resin solution weighed out from the phenoxy resin solution so as to contain 50 g of solid content, 49 g of the urethane acrylate, 1 g of phosphate ester acrylate, and t- as a curing agent that generates free radicals by heating. An adhesive composition-containing liquid was obtained by mixing 5 g of hexylperoxy-2-ethylhexanoate. And conductive particle No. with respect to 100 mass parts of this adhesive composition containing liquid. 5 parts by mass of 1 was dispersed to prepare a circuit connecting material-containing liquid. And this circuit connection material containing liquid is apply | coated to a 50-micrometer-thick PET film which surface-treated one side using a coating apparatus, and it dried by hot air for 3 minutes at 70 degreeC, and the film-like thickness of 20 micrometers on a PET film Circuit connection material 2 was obtained.

(Production of circuit connection materials 3 to 29)
In the circuit connection material 1, conductive particles No. In place of conductive particles No. 1 Film-like circuit connection materials 3 to 29 were obtained in the same manner as the circuit connection material 1 except that 2 to 28 were used. Table 2 shows the characteristics of the conductive particles contained in each circuit connection material.

Example 1
As a first circuit member, a flexible circuit board (hereinafter referred to as “FPC”) having a two-layer structure composed of a polyimide film (thickness: 38 μm) and Sn-plated Cu foil (thickness: 8 μm) was prepared. The FPC circuit has a line width of 18 μm and a pitch of 50 μm.

  As a second circuit member, a glass substrate (thickness 1.1 mm) having an ITO circuit electrode (electrode film thickness: 50 nm, surface resistance <20Ω) on the surface was prepared. The circuit of the second circuit member has a line width of 25 μm and a pitch of 50 μm.

  Next, the circuit connection material 1 cut into a predetermined size (1.5 × 30 mm) was pasted on the second circuit member, and was temporarily connected by heating and pressing at 70 ° C. and 1.0 MPa for 5 seconds. Next, after the PET film was peeled off, the FPC was arranged so that the circuit connecting material 1 was sandwiched between the FPC and the second circuit member, and the circuit of the FPC and the circuit of the second circuit member were aligned. Next, heating and pressurization were performed from above the FPC under the conditions of 180 ° C., 3 MPa, and 15 seconds, and the FPC and the second circuit member were permanently connected. Thus, a circuit member connection structure of Example 1 was obtained.

(Example 2)
As the first circuit member, the same FPC as in Example 1 was prepared. Next, a glass substrate (thickness: 1.1 mm) provided with an IZO circuit electrode (electrode film thickness: 50 nm, surface resistance <20Ω) on the surface was prepared as a second circuit member. The circuit of the second circuit member has a line width of 25 μm and a pitch of 50 μm. And the temporary connection by the circuit connection material 1 and this connection were made like the connection method of Example 1, and the connection structure of the circuit member of Example 2 was obtained.

(Example 3)
As the first circuit member, the same FPC as in Example 1 was prepared. Next, the glass substrate provided with the ITO circuit electrode (electrode film thickness: 50 nm) similar to Example 1 as a 2nd circuit member was prepared. And the circuit connection material 2 cut | judged to the predetermined | prescribed size (1.5x30 mm) was affixed on the 2nd circuit member, and it heated and pressurized for 3 seconds at 70 degreeC and 1.0 MPa, and temporarily connected. Next, after the PET film was peeled off, the FPC was arranged so that the circuit connecting material 2 was sandwiched between the FPC and the second circuit member, and the circuit of the FPC and the circuit of the second circuit member were aligned. Next, heating and pressurization were performed from above the FPC under the conditions of 170 ° C., 3 MPa, and 10 seconds to make a main connection between the FPC and the second circuit member, whereby a circuit member connection structure of Example 3 was obtained.

Example 4
As the first circuit member, the same FPC as in Example 1 was prepared. Next, the glass substrate provided with the same IZO circuit electrode as Example 2 was prepared as a 2nd circuit member. And the temporary connection by the circuit connection material 2 and this connection were made like the connection method of Example 3, and the connection structure of the circuit member of Example 4 was obtained.

(Example 5)
As the first circuit member, the same FPC as in Example 1 was prepared. Next, the glass substrate provided with the ITO circuit electrode (electrode film thickness: 50 nm) similar to Example 1 as a 2nd circuit member was prepared. And the temporary connection by the circuit connection material 3 and this connection were made like the connection method of Example 1, and the connection structure of the circuit member of Example 5 was obtained.

(Example 6)
As the first circuit member, the same FPC as in Example 1 was prepared. Next, the glass substrate provided with the same IZO circuit electrode as Example 2 was prepared as a 2nd circuit member. And the temporary connection by the circuit connection material 3 and this connection were made like the connection method of Example 2, and the connection structure of the circuit member of Example 6 was obtained.

(Example 7)
As the first circuit member, the same FPC as in Example 1 was prepared. Next, the glass substrate provided with the ITO circuit electrode (electrode film thickness: 50 nm) similar to Example 1 as a 2nd circuit member was prepared. And the temporary connection by the circuit connection material 4 and this connection were made like the connection method of Example 1, and the connection structure of the circuit member of Example 7 was obtained.

(Example 8)
As the first circuit member, the same FPC as in Example 1 was prepared. Next, the glass substrate provided with the same IZO circuit electrode as Example 2 was prepared as a 2nd circuit member. And the temporary connection by the circuit connection material 4 and this connection were made like the connection method of Example 2, and the connection structure of the circuit member of Example 8 was obtained.

Example 9
As the first circuit member, the same FPC as in Example 1 was prepared. Next, the glass substrate provided with the ITO circuit electrode (electrode film thickness: 50 nm) similar to Example 1 as a 2nd circuit member was prepared. And the temporary connection by the circuit connection material 7 and this connection were made like the connection method of Example 1, and the connection structure of the circuit member of Example 9 was obtained.

(Example 10)
As the first circuit member, the same FPC as in Example 1 was prepared. Next, the glass substrate provided with the same IZO circuit electrode as Example 2 was prepared as a 2nd circuit member. And the temporary connection by the circuit connection material 7 and this connection were made like the connection method of Example 2, and the connection structure of the circuit member of Example 10 was obtained.

(Example 11)
As the first circuit member, the same FPC as in Example 1 was prepared. Next, the glass substrate provided with the ITO circuit electrode (electrode film thickness: 50 nm) similar to Example 1 as a 2nd circuit member was prepared. And the temporary connection by the circuit connection material 8 and this connection were made like the connection method of Example 1, and the connection structure of the circuit member of Example 11 was obtained.

(Example 12)
As the first circuit member, the same FPC as in Example 1 was prepared. Next, the glass substrate provided with the same IZO circuit electrode as Example 2 was prepared as a 2nd circuit member. And the temporary connection by the circuit connection material 8 and this connection were made like the connection method of Example 2, and the connection structure of the circuit member of Example 12 was obtained.

(Example 15)
As the first circuit member, the same FPC as in Example 1 was prepared. Next, the glass substrate provided with the ITO circuit electrode (electrode film thickness: 50 nm) similar to Example 1 as a 2nd circuit member was prepared. And the temporary connection by the circuit connection material 12 and this connection were made like the connection method of Example 1, and the connection structure of the circuit member of Example 15 was obtained.

(Example 16)
As the first circuit member, the same FPC as in Example 1 was prepared. Next, the glass substrate provided with the same IZO circuit electrode as Example 2 was prepared as a 2nd circuit member. And the temporary connection by the circuit connection material 12 and this connection were made like the connection method of Example 2, and the connection structure of the circuit member of Example 16 was obtained.

(Example 17)
As the first circuit member, the same FPC as in Example 1 was prepared. Next, the glass substrate provided with the ITO circuit electrode (electrode film thickness: 50 nm) similar to Example 1 as a 2nd circuit member was prepared. And the temporary connection by the circuit connection material 13 and this connection were made like the connection method of Example 1, and the connection structure of the circuit member of Example 17 was obtained.

(Example 18)
As the first circuit member, the same FPC as in Example 1 was prepared. Next, the glass substrate provided with the same IZO circuit electrode as Example 2 was prepared as a 2nd circuit member. And the temporary connection by the circuit connection material 13 and this connection were made like the connection method of Example 2, and the connection structure of the circuit member of Example 18 was obtained.

(Example 21)
As the first circuit member, the same FPC as in Example 1 was prepared. Next, the glass substrate provided with the ITO circuit electrode (electrode film thickness: 50 nm) similar to Example 1 as a 2nd circuit member was prepared. And the temporary connection by the circuit connection material 17 and this connection were made like the connection method of Example 1, and the connection structure of the circuit member of Example 21 was obtained.

(Example 22)
As the first circuit member, the same FPC as in Example 1 was prepared. Next, the glass substrate provided with the same IZO circuit electrode as Example 2 was prepared as a 2nd circuit member. And the temporary connection by the circuit connection material 17 and this connection were made like the connection method of Example 2, and the connection structure of the circuit member of Example 22 was obtained.

(Example 23)
As the first circuit member, the same FPC as in Example 1 was prepared. Next, the glass substrate provided with the ITO circuit electrode (electrode film thickness: 50 nm) similar to Example 1 as a 2nd circuit member was prepared. And the temporary connection by the circuit connection material 18 and this connection were made like the connection method of Example 1, and the connection structure of the circuit member of Example 23 was obtained.

(Example 24)
As the first circuit member, the same FPC as in Example 1 was prepared. Next, the glass substrate provided with the same IZO circuit electrode as Example 2 was prepared as a 2nd circuit member. And the temporary connection by the circuit connection material 18 and this connection were made like the connection method of Example 2, and the connection structure of the circuit member of Example 24 was obtained.

(Example 27)
As the first circuit member, the same FPC as in Example 1 was prepared. Next, the glass substrate provided with the ITO circuit electrode (electrode film thickness: 50 nm) similar to Example 1 as a 2nd circuit member was prepared. And the temporary connection by the circuit connection material 22 and this connection were made like the connection method of Example 1, and the connection structure of the circuit member of Example 27 was obtained.

(Example 28)
As the first circuit member, the same FPC as in Example 1 was prepared. Next, the glass substrate provided with the same IZO circuit electrode as Example 2 was prepared as a 2nd circuit member. And the temporary connection by the circuit connection material 22 and this connection were made like the connection method of Example 2, and the connection structure of the circuit member of Example 28 was obtained.

(Example 29)
As the first circuit member, the same FPC as in Example 1 was prepared. Next, the glass substrate provided with the ITO circuit electrode (electrode film thickness: 50 nm) similar to Example 1 as a 2nd circuit member was prepared. And the temporary connection by the circuit connection material 23 and this connection were made like the connection method of Example 1, and the connection structure of the circuit member of Example 29 was obtained.

(Example 30)
As the first circuit member, the same FPC as in Example 1 was prepared. Next, the glass substrate provided with the same IZO circuit electrode as Example 2 was prepared as a 2nd circuit member. And the temporary connection by the circuit connection material 23 and this connection were made like the connection method of Example 2, and the connection structure of the circuit member of Example 30 was obtained.

(Comparative Example 1)
As the first circuit member, the same FPC as in Example 1 was prepared. Next, the glass substrate provided with the ITO circuit electrode (electrode film thickness: 50 nm) similar to Example 1 as a 2nd circuit member was prepared. And the temporary connection by the circuit connection material 5 and this connection were made like the connection method of Example 1, and the connection structure of the circuit member of the comparative example 1 was obtained.

(Comparative Example 2)
As the first circuit member, the same FPC as in Example 1 was prepared. Next, the glass substrate provided with the same IZO circuit electrode as Example 2 was prepared as a 2nd circuit member. And the temporary connection by the circuit connection material 5 and this connection were made like the connection method of Example 2, and the connection structure of the circuit member of the comparative example 2 was obtained.

(Comparative Example 3)
As the first circuit member, the same FPC as in Example 1 was prepared. Next, the glass substrate provided with the ITO circuit electrode (electrode film thickness: 50 nm) similar to Example 1 as a 2nd circuit member was prepared. And the temporary connection by the circuit connection material 6 and this connection were made like the connection method of Example 1, and the connection structure of the circuit member of the comparative example 3 was obtained.

(Comparative Example 4)
As the first circuit member, the same FPC as in Example 1 was prepared. Next, the glass substrate provided with the same IZO circuit electrode as Example 2 was prepared as a 2nd circuit member. And the temporary connection by the circuit connection material 6 and this connection were made like the connection method of Example 2, and the connection structure of the circuit member of the comparative example 4 was obtained.

(Comparative Example 5)
As the first circuit member, the same FPC as in Example 1 was prepared. Next, the glass substrate provided with the ITO circuit electrode (electrode film thickness: 50 nm) similar to Example 1 as a 2nd circuit member was prepared. And the temporary connection by the circuit connection material 10 and this connection were made like the connection method of Example 1, and the connection structure of the circuit member of the comparative example 5 was obtained.

(Comparative Example 6)
As the first circuit member, the same FPC as in Example 1 was prepared. Next, the glass substrate provided with the same IZO circuit electrode as Example 2 was prepared as a 2nd circuit member. And the temporary connection by the circuit connection material 10 and this connection were made like the connection method of Example 2, and the connection structure of the circuit member of the comparative example 6 was obtained.

(Comparative Example 7)
As the first circuit member, the same FPC as in Example 1 was prepared. Next, the glass substrate provided with the ITO circuit electrode (electrode film thickness: 50 nm) similar to Example 1 as a 2nd circuit member was prepared. And the temporary connection by the circuit connection material 11 and this connection were made like the connection method of Example 1, and the connection structure of the circuit member of the comparative example 7 was obtained.

(Comparative Example 8)
As the first circuit member, the same FPC as in Example 1 was prepared. Next, the glass substrate provided with the same IZO circuit electrode as Example 2 was prepared as a 2nd circuit member. And the temporary connection by the circuit connection material 11 and this connection were made like the connection method of Example 2, and the connection structure of the circuit member of the comparative example 8 was obtained.

(Comparative Example 9)
As the first circuit member, the same FPC as in Example 1 was prepared. Next, the glass substrate provided with the ITO circuit electrode (electrode film thickness: 50 nm) similar to Example 1 as a 2nd circuit member was prepared. And the temporary connection by the circuit connection material 15 and this connection were made like the connection method of Example 1, and the connection structure of the circuit member of the comparative example 9 was obtained.

(Comparative Example 10)
As the first circuit member, the same FPC as in Example 1 was prepared. Next, the glass substrate provided with the same IZO circuit electrode as Example 2 was prepared as a 2nd circuit member. And the temporary connection by the circuit connection material 15 and this connection were made like the connection method of Example 2, and the connection structure of the circuit member of the comparative example 10 was obtained.

(Comparative Example 11)
As the first circuit member, the same FPC as in Example 1 was prepared. Next, the glass substrate provided with the ITO circuit electrode (electrode film thickness: 50 nm) similar to Example 1 as a 2nd circuit member was prepared. And the temporary connection by the circuit connection material 16 and this connection were made like the connection method of Example 1, and the connection structure of the circuit member of the comparative example 11 was obtained.

(Comparative Example 12)
As the first circuit member, the same FPC as in Example 1 was prepared. Next, the glass substrate provided with the same IZO circuit electrode as Example 2 was prepared as a 2nd circuit member. And the temporary connection by the circuit connection material 16 and this connection were made like the connection method of Example 2, and the connection structure of the circuit member of the comparative example 12 was obtained.

(Comparative Example 13)
As the first circuit member, the same FPC as in Example 1 was prepared. Next, the glass substrate provided with the ITO circuit electrode (electrode film thickness: 50 nm) similar to Example 1 as a 2nd circuit member was prepared. And the temporary connection by the circuit connection material 20 and this connection were made like the connection method of Example 1, and the connection structure of the circuit member of the comparative example 13 was obtained.

(Comparative Example 14)
As the first circuit member, the same FPC as in Example 1 was prepared. Next, the glass substrate provided with the same IZO circuit electrode as Example 2 was prepared as a 2nd circuit member. And the temporary connection by the circuit connection material 20 and this connection were made like the connection method of Example 2, and the connection structure of the circuit member of the comparative example 14 was obtained.

(Comparative Example 15)
As the first circuit member, the same FPC as in Example 1 was prepared. Next, the glass substrate provided with the ITO circuit electrode (electrode film thickness: 50 nm) similar to Example 1 as a 2nd circuit member was prepared. And the temporary connection by the circuit connection material 21 and this connection were made like the connection method of Example 1, and the connection structure of the circuit member of the comparative example 15 was obtained.

(Comparative Example 16)
As the first circuit member, the same FPC as in Example 1 was prepared. Next, the glass substrate provided with the same IZO circuit electrode as Example 2 was prepared as a 2nd circuit member. And the temporary connection by the circuit connection material 21 and this connection were made like the connection method of Example 2, and the connection structure of the circuit member of the comparative example 16 was obtained.

(Comparative Example 17)
As the first circuit member, the same FPC as in Example 1 was prepared. Next, the glass substrate provided with the ITO circuit electrode (electrode film thickness: 50 nm) similar to Example 1 as a 2nd circuit member was prepared. And the temporary connection by the circuit connection material 25 and this connection were made like the connection method of Example 1, and the connection structure of the circuit member of the comparative example 17 was obtained.

(Comparative Example 18)
As the first circuit member, the same FPC as in Example 1 was prepared. Next, the glass substrate provided with the same IZO circuit electrode as Example 2 was prepared as a 2nd circuit member. And the temporary connection by the circuit connection material 25 and this connection were made like the connection method of Example 2, and the connection structure of the circuit member of the comparative example 18 was obtained.

(Comparative Example 19)
As the first circuit member, the same FPC as in Example 1 was prepared. Next, the glass substrate provided with the ITO circuit electrode (electrode film thickness: 50 nm) similar to Example 1 as a 2nd circuit member was prepared. And the temporary connection by the circuit connection material 26 and this connection were made like the connection method of Example 1, and the connection structure of the circuit member of the comparative example 19 was obtained.

(Comparative Example 20)
As the first circuit member, the same FPC as in Example 1 was prepared. Next, the glass substrate provided with the same IZO circuit electrode as Example 2 was prepared as a 2nd circuit member. And the temporary connection by the circuit connection material 26 and this connection were made like the connection method of Example 2, and the connection structure of the circuit member of the comparative example 20 was obtained.

(Comparative Example 21)
As the first circuit member, the same FPC as in Example 1 was prepared. Next, the glass substrate provided with the ITO circuit electrode (electrode film thickness: 50 nm) similar to Example 1 as a 2nd circuit member was prepared. And the temporary connection by the circuit connection material 27 and this connection were made like the connection method of Example 1, and the connection structure of the circuit member of the comparative example 21 was obtained.

(Comparative Example 22)
As the first circuit member, the same FPC as in Example 1 was prepared. Next, the glass substrate provided with the same IZO circuit electrode as Example 2 was prepared as a 2nd circuit member. And the temporary connection by the circuit connection material 27 and this connection were made like the connection method of Example 2, and the connection structure of the circuit member of the comparative example 22 was obtained.

(Comparative Example 23)
As the first circuit member, the same FPC as in Example 1 was prepared. Next, the glass substrate provided with the ITO circuit electrode (electrode film thickness: 50 nm) similar to Example 1 as a 2nd circuit member was prepared. And the temporary connection by the circuit connection material 28 and this connection were made like the connection method of Example 1, and the connection structure of the circuit member of the comparative example 23 was obtained.

(Comparative Example 24)
As the first circuit member, the same FPC as in Example 1 was prepared. Next, the glass substrate provided with the same IZO circuit electrode as Example 2 was prepared as a 2nd circuit member. And the temporary connection by the circuit connection material 28 and this connection were made like the connection method of Example 2, and the connection structure of the circuit member of the comparative example 24 was obtained.

(Comparative Example 25)
As the first circuit member, the same FPC as in Example 1 was prepared. Next, the glass substrate provided with the ITO circuit electrode (electrode film thickness: 50 nm) similar to Example 1 as a 2nd circuit member was prepared. And the temporary connection by the circuit connection material 29 and this connection were made like the connection method of Example 1, and the connection structure of the circuit member of the comparative example 25 was obtained.

(Comparative Example 26)
As the first circuit member, the same FPC as in Example 1 was prepared. Next, the glass substrate provided with the same IZO circuit electrode as Example 2 was prepared as a 2nd circuit member. And the temporary connection by the circuit connection material 29 and this connection were made like the connection method of Example 2, and the connection structure of the circuit member of the comparative example 26 was obtained.

(Comparative Example 27)
As the first circuit member, the same FPC as in Example 1 was prepared. Next, a glass substrate (thickness 1.1 mm) having an ITO circuit electrode (electrode film thickness: 25 nm, surface resistance <40Ω) on the surface was prepared as a second circuit member. The circuit of the second circuit member has a line width of 25 μm and a pitch of 50 μm. And the temporary connection by the circuit connection material 1 and this connection were made like the connection method of Example 1, and the connection structure of the circuit member of the comparative example 27 was obtained.

(Measurement of connection resistance)
About connection structure of the circuit member of Examples 1-12, 15-18, 21-24, 27-30, and Comparative Examples 1-27, the connection between the circuit electrode of FPC and the circuit electrode of the 2nd circuit member The resistance value was measured with a multimeter. As the connection resistance value, the resistance value immediately after the connection (initial resistance value) and the resistance value after being held in a high-temperature and high-humidity bath at 80 ° C. and 95% RH (after high-temperature and high-humidity treatment) (resistance after treatment) Value) was measured respectively. The connection resistance value was the sum (x + 3σ) of an average value of 37 resistances between adjacent circuits and a value obtained by triple the standard deviation. The resistance increase rate is a percentage obtained by dividing the increase from the initial resistance value to the processed resistance value by the initial resistance value as a percentage, and the formula (resistance value after processing−initial resistance value) / initial resistance value × Calculated at 100. Tables 2 and 3 show the connection resistance value measurement results and the resistance increase rate calculation results. Note that the smaller the connection resistance value, the better the electrical connection between the opposing circuit electrodes, and the smaller the resistance increase rate, the higher the long-term reliability of the electrical characteristics between the circuit electrodes.

  In Examples 1 and 2 using the conductive particles in which the metal (outermost layer metal) constituting the outermost layer of the conductive particles is Ni and the protrusions are formed on the outermost layer, the resistance increase rate is 5% or less. Good value was shown. On the other hand, Comparative Examples 21 and 22 using conductive particles in which the outermost layer metal is Ni but no protrusions are formed on the outermost layer, and Comparative Examples 23 to 26 using conductive particles whose outermost layer metal is Au. Then, the resistance increase rate was higher than all Examples including Examples 1 and 2.

  Moreover, as shown in Examples 1-12, 15-18, 21-24, 27-30, the resistance increase rate is 5% when the hardness is in a certain range according to the diameter (particle diameter) of the conductive particles. It was found that the following values were very good.

  On the other hand, in Comparative Examples 1, 2, 5, 6, 9, 10, 13, 14, 17, and 18 in which the hardness of the conductive particles was too low, the resistance increase rate was as high as about 10%. This is because the conductive particles are too soft, and when the distance between the circuit electrodes facing each other changes due to the high temperature and high humidity treatment, the shape of the conductive particles cannot follow the change in the distance between the circuit electrodes. This is considered to be due to the fact that the conductive particles and the circuit electrode could not be contacted sufficiently.

  Further, in Comparative Examples 3, 4, 7, 8, 11, 12, 15, 16, 19, and 20 where the hardness of the conductive particles was too high, the initial connection resistance was high, and the rate of increase in resistance was particularly high at 10% or more. This is probably because the conductive particles are too hard and the conductive particles are not sufficiently flattened, so that the contact area between the conductive particles and the circuit electrode is reduced.

  In addition, Example 1 in which circuit members whose circuit electrodes are made of ITO having a thickness of 50 nm are connected by the circuit connection material 1, and circuit members whose circuit electrodes are made of ITO having a thickness of 25 nm are connected to the circuit connection material 1. When compared with Comparative Example 27 connected in (1), the resistance increase rate of Comparative Example 27 was around 20%, whereas the resistance increase rate of Example 1 was as small as less than 5%. From this, the rate of increase in resistance due to the combination of a circuit connecting material including conductive particles having protrusions formed on the outermost layer made of Ni and having hardness corresponding to a predetermined diameter, and a circuit electrode made of ITO or IZO It has been found that the suppression effect (improvement of connection reliability) is significant when the thickness of the circuit electrode is 50 nm or more.

  As described above, according to the present invention, even if the surface of the circuit electrode is flat, it is possible to achieve good electrical connection between the facing circuit electrodes and to achieve long-term reliability of the electrical characteristics between the circuit electrodes. It is possible to provide a circuit connection material and a circuit member connection structure that can sufficiently increase the resistance.

DESCRIPTION OF SYMBOLS 1 ... Connection structure of a circuit member, 10 ... Circuit connection member, 11 ... Insulative substance, 12 ... Conductive particle, 14 ... Projection part, 21 ... Nucleus, 21a ... · Core portion, 21b ··· Nucleus-side projection, 22 · · · Outermost layer (metal layer), 30 · · · first circuit member, 31 · · · first circuit board, 31a · · · main surface 32 ... first circuit electrode, 40 ... second circuit member, 41 ... second circuit board, 41a ... main surface, 42 ... second circuit electrode, H. ..Height of conductive particle protrusions, S. Distance between adjacent protrusions.

Claims (8)

The first circuit electrode is interposed between a first circuit member having a first circuit electrode and a second circuit member facing the first circuit member and having a second circuit electrode. And a circuit connecting material for electrically connecting the second circuit electrode to each other,
An adhesive composition and conductive particles having a diameter of 0.5 μm or more and less than 4 μm,
The outermost layer of the conductive particles is made of Ni or Ni alloy having a Bickers hardness of 300 Hv or more,
A portion of the outermost layer protrudes outward to form a protrusion,
When the diameter of the conductive particles is 3 μm or more and less than 4 μm, the hardness of the conductive particles is 900 to 1400 kgf / mm ² ;
When the diameter of the conductive particles is 2 μm or more and less than 3 μm, the hardness of the conductive particles is 1000 to 1700 kgf / mm ² ;
A circuit connection material, wherein the conductive particles have a hardness of 1200 to 2000 kgf / mm ² when the diameter of the conductive particles is 0.5 μm or more and less than 2 μm. The protrusion has a height of 50 to 500 nm,
A part of the outermost layer protrudes outward to form a plurality of the protrusions,
The circuit connection material according to claim 1, wherein a distance between adjacent protrusions is 1000 nm or less.   The circuit connection material according to claim 1, which is in the form of a film. The circuit connection material according to claim 1 is interposed between the first circuit member and the second circuit member, and the first circuit electrode and the second circuit member are interposed between the first circuit member and the second circuit member. Is electrically connected to the circuit electrode,
A circuit member connection structure, wherein the first and second circuit electrodes have a thickness of 50 nm or more.   5. The circuit member connection structure according to claim 4, wherein the first or second circuit electrode is indium-tin oxide.   The circuit member connection structure according to claim 4, wherein the first or second circuit electrode is indium-zinc oxide.   5. The circuit member connection structure according to claim 4, wherein only the surface of the first or second circuit electrode is indium-tin oxide. 5. The circuit member connection structure according to claim 4, wherein only the surface of the first or second circuit electrode is indium-zinc oxide.

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