JP2013103947A - Adhesive film for circuit connection, circuit-connected body using the adhesive film, and method of producing the circuit-connected body - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an adhesive film for circuit connection, with which sufficiently-low connection resistance and sufficient impression strength can be obtained.SOLUTION: An adhesive film for circuit connection includes: a conductive adhesive layer that contains an adhesive component containing a curing agent and further contains conductive particles; and an insulating adhesive layer that contains the adhesive component containing the curing agent but does not contain the conductive particles. The thickness of the conductive adhesive layer is twice or lower as large as an average grain size of the conductive particles. The mass ratio of the curing agent the adhesive component contained in the conductive adhesive layer contains to the adhesive component is lower than the mass ratio of the curing agent the adhesive component contained in the insulating adhesive layer contains to the adhesive component.

Description

  The present invention relates to an adhesive film for circuit connection, a circuit connection body using the same, and a method for manufacturing the circuit connection body.

  A circuit connecting material that heats and presses opposite circuits to electrically connect electrodes in the pressing direction, for example, an anisotropic conductive adhesive film in which conductive particles are dispersed in an epoxy adhesive or an acrylic adhesive, Widely used for electrical connection between TCP (Tape Carrier Package) or COF (Chip On Flex) and LCD panel, or TCP or COF and printed wiring board, which is mainly equipped with a semiconductor that drives liquid crystal display (LCD) ing.

  Recently, even when semiconductors are directly mounted face-down on LCD panels or printed wiring boards, flip chip mounting, which is advantageous for thinning and narrow pitch connection, has been adopted instead of the conventional wire bonding method. A direction conductive adhesive film is used as a circuit connecting material (see, for example, Patent Documents 1 to 4).

  In recent years, with the increase in COF and fine pitch of LCD modules, there has been a problem that a short circuit occurs between adjacent electrodes during connection using a circuit connection material. As a countermeasure for the above-described problem, there is a technique for preventing a short circuit by dispersing insulating particles in an adhesive component (see, for example, Patent Documents 5 to 9).

  In addition, in order to adhere to a wiring member made of an insulating organic material or glass, or a wiring member having silicon nitride, silicone resin and / or polyimide resin on at least a part of the surface, the adhesive component contains silicone particles. In order to reduce internal stress based on the difference in coefficient of thermal expansion after bonding, there is a technique of dispersing rubber particles in an adhesive (for example, see Patent Document 11).

  Furthermore, in order to improve the capturing efficiency of the conductive particles and prevent short-circuiting due to the aggregation of the conductive particles at the glass edge portion of the substrate to be connected, an anisotropic conductive adhesive layer in which the conductive particles are dispersed and an insulating adhesive layer are provided. There is a technique of a circuit connection material having a two-layer structure having a stacked structure (see, for example, Patent Document 12).

JP 59-120436 A JP-A-60-191228 JP-A-1-251787 JP-A-7-90237 JP 51-20941 A JP-A-3-29207 JP-A-4-174980 Japanese Patent No. 3048197 Japanese Patent No. 3477367 International Publication No. 01/014484 Pamphlet JP 2001-323249 A JP 2009-1708988 A

  However, in recent circuit members, the electrodes have become higher in definition and the resin of the circuit connection material is not sufficiently removed at the time of circuit connection, so that problems such as increased connection resistance and insufficient indentation strength have arisen.

  Then, an object of this invention is to provide the adhesive film for circuit connection which can obtain a sufficiently low connection resistance and sufficient indentation intensity | strength.

  As a result of intensive studies to solve the above problems, the present inventors can improve the connection resistance and indentation strength by adjusting the thickness of the conductive adhesive layer and the content of the curing agent. As a result, the present invention has been completed.

  That is, the present invention comprises a conductive adhesive layer containing an adhesive component containing a curing agent and conductive particles, and an insulating adhesive layer containing an adhesive component containing a curing agent and no conductive particles. An adhesive film for circuit connection, wherein the thickness of the conductive adhesive layer is not more than twice the average particle size of the conductive particles, and the curing agent contained in the adhesive component contained in the conductive adhesive layer It is related with the adhesive film for circuit connections whose mass ratio with respect to the said adhesive component is less than the mass ratio with respect to the said adhesive component of the hardening | curing agent which the adhesive agent component contained in the said insulating adhesive layer contains.

  When the thickness of the conductive adhesive layer is not more than twice the average particle size of the conductive particles, the movement of the conductive particles can be suppressed, and the increase in connection resistance can be suppressed. Moreover, the mass ratio of the curing agent contained in the adhesive component contained in the conductive adhesive layer to the adhesive component is relative to the adhesive component of the curing agent contained in the adhesive component contained in the insulating adhesive layer. By being less than the mass ratio, sufficiently low connection resistance and sufficient indentation strength can be obtained.

  The adhesive component preferably further contains a thermoplastic resin and a radical polymerizable compound, and the curing agent is preferably a radical polymerization initiator. By using such an adhesive component, curing at a low temperature and in a short time (low temperature rapid curing) becomes possible.

  Further, the present invention provides a circuit member that is interposed between a pair of circuit members disposed opposite to each other and the pair of circuit members so that circuit electrodes of each circuit member are electrically connected to each other. It is a circuit connection body provided with the connection part to adhere | attach, Comprising: The said connection part is related with the circuit connection body which consists of hardened | cured material of the adhesive film for circuit connection of this invention. The circuit connection body of the present invention has a sufficiently low connection resistance and a sufficient indentation strength by forming the connection portion using the above-mentioned adhesive film for circuit connection of the present invention.

  Furthermore, the present invention provides a circuit member which is interposed between a pair of circuit members arranged opposite to each other and the pair of circuit members so that circuit electrodes of each circuit member are electrically connected to each other. A connecting part for bonding, wherein the adhesive film for circuit connection of the present invention is interposed between the pair of circuit members, and the whole is heated and pressurized, It is related with the manufacturing method of the said circuit connection body which provides the said connection part which consists of hardened | cured material of the adhesive film for circuit connections. According to the manufacturing method of the present invention, it is possible to obtain a circuit connection body having a sufficiently low connection resistance and a sufficient indentation strength.

  ADVANTAGE OF THE INVENTION According to this invention, the adhesive film for circuit connection which can obtain sufficiently low connection resistance and sufficient indentation intensity | strength, the circuit connection body using the same, and the manufacturing method of a circuit connection body can be provided.

It is an end view which shows one Embodiment of the adhesive film for circuit connections of this invention.

  Hereinafter, embodiments for carrying out the present invention will be described in detail with reference to the drawings as necessary. However, the present invention is not limited to the following embodiments. In the present specification, “(meth) acrylic acid” means “acrylic acid” and its corresponding “methacrylic acid”, and “(meth) acrylate” means “acrylate” and its corresponding “methacrylate”. And “(meth) acryloxy” means “acryloxy” and its corresponding “methacryloxy”.

  The adhesive film for circuit connection of the present invention (hereinafter also simply referred to as “adhesive film”) includes a conductive adhesive layer containing conductive particles and an insulating adhesive layer not containing conductive particles.

  The thickness of the conductive adhesive layer is not more than twice the average particle size of the conductive particles. Thereby, the movement of the conductive particles is suppressed, and an increase in connection resistance can be suppressed. Although the thickness should just be 2 times or less of the average particle diameter of electroconductive particle, it is preferable in it being 20-100% of thickness with respect to the average particle diameter of electroconductive particle, and being 25-75% of thickness. More preferred. Specifically, the thickness is preferably 1 to 5 μm, and more preferably 1 to 4 μm.

  On the other hand, the thickness of the insulating adhesive layer is preferably 2 to 21 μm, and more preferably 4 to 14 μm.

  The average particle diameter of the conductive particles can be determined as follows. That is, one core particle is arbitrarily selected, and this is observed with a differential scanning electron microscope, and its maximum diameter and minimum diameter are measured. The square root of the product of the maximum diameter and the minimum diameter is defined as the particle diameter of the particle. By this method, the particle diameter of 50 arbitrarily selected core particles is measured, and the average value is taken as the average particle diameter of the conductive particles.

  The average particle diameter of the conductive particles is preferably 1 to 10 μm, preferably 1 to 8 μm, and preferably 2 to 6 μm from the viewpoint that the short circuit between adjacent electrodes decreases when the electrode height is lower than the electrode height of the circuit to be connected. More preferably, it is 3 to 5 μm, particularly preferably 3 to 4 μm.

The 10% compression elastic modulus (K value) of the conductive particles is preferably 100 to 1000 kgf / mm ² .

  Examples of the conductive particles include metal particles such as Au, Ag, Ni, Cu, and solder, and carbon. The conductive particles may be particles in which core particles are covered with one or more layers, and the outermost layer is a conductive layer. In this case, in order to obtain a sufficient pot life, the outermost layer is preferably Au, Ag, or a platinum group noble metal, more preferably Au, than transition metals such as Ni and Cu.

  The conductive particles may be those in which the surface of a transition metal such as Ni is coated with a noble metal such as Au. Furthermore, the conductive particles may be those obtained by coating nonconductive glass, ceramic, plastic, or other insulating particles with a conductive material such as metal. When conductive particles are made of insulating particles coated with a conductive material and the outermost layer is precious metal and the core insulating particles are plastic, or the conductive particles are hot-melt metal particles, they are deformed by heating and pressing. This is preferable because the contact area with the electrode increases at the time of connection and the reliability is improved.

  In order to obtain good resistance, the thickness of the noble metal coating layer is preferably 100 mm or more. However, when a noble metal coating layer is provided on a transition metal such as Ni, the oxidation-reduction action caused by the noble metal coating layer deficiency or the noble metal coating layer deficiency generated when the conductive particles are mixed and dispersed. Since free radicals are generated and pot life is reduced, the thickness of the coating layer is preferably 300 mm or more when using a radical polymerization type adhesive component.

  Although electroconductive particle can be contained normally in 0.1-30 volume parts with respect to 100 volume parts of adhesive components, suitable content changes with uses. For example, 0.1 to 10 parts by volume is more preferable in order to more sufficiently prevent a short circuit between adjacent circuits due to conductive particles.

  The minimum melt viscosity ratio of the conductive adhesive layer to the insulating adhesive layer is preferably at least 10 times or more. Thereby, the movement inhibitory effect of the conductive particles during pressurization is further improved. In addition, although the upper limit of the said minimum melt viscosity ratio is not specifically limited, For example, it can be 1000 times or less.

  In the adhesive film of the present invention, the mass ratio of the curing agent contained in the adhesive component contained in the conductive adhesive layer to the adhesive component contains the adhesive component contained in the insulating adhesive layer. Less than the mass ratio of the curing agent to the adhesive component. As a result, the fluidity of the conductive adhesive layer is improved, and the resin is sufficiently removed at the time of circuit connection. As a result, a sufficiently low connection resistance and a sufficient indentation strength can be obtained.

  The curing agent content of the adhesive component contained in the conductive adhesive layer is preferably 3 to 10% by mass, and more preferably 4 to 8% by mass. On the other hand, the curing agent content of the adhesive component contained in the insulating adhesive layer is preferably 4 to 11% by mass, and more preferably 5 to 9% by mass.

  The adhesive component contained in the conductive adhesive layer and the insulating adhesive layer further contains a thermoplastic resin and a radical polymerizable compound, and the curing agent is preferably a radical polymerization initiator. By using such an adhesive component, curing at a low temperature and in a short time (low temperature rapid curing) becomes possible.

  Examples of the thermoplastic resin include a phenoxy resin, an acrylic resin, a polyimide resin, a polyurethaneimide resin, a polyamideimide resin, and a polyurethane resin. In particular, polyester urethane and an ethylene-vinyl acetate copolymer are preferably used.

  A radically polymerizable compound is a compound having a functional group that is polymerized by radicals, and specific examples thereof include (meth) acrylates and maleimide compounds. The blending amount of the radical polymerizable compound is preferably 25 to 55% by mass and more preferably 30 to 50% by mass with respect to the entire solid content of the adhesive component.

  Examples of the (meth) acrylate include urethane (meth) acrylate, methyl (meth) acrylate, ethyl (meth) acrylate, isopropyl (meth) acrylate, isobutyl (meth) acrylate, ethylene glycol di (meth) acrylate, diethylene glycol di ( (Meth) acrylate, triethylene glycol di (meth) acrylate, trimethylolpropane tri (meth) acrylate, tetramethylolmethane tetra (meth) acrylate, 2-hydroxy-1,3-di (meth) acryloxypropane, 2,2 -Bis [4-((meth) acryloxymethoxy) phenyl] propane, 2,2-bis [4-((meth) acryloxypolyethoxy) phenyl] propane, dicyclopentenyl (meth) acrylate, tris Rodekaniru (meth) acrylate, bis ((meth) acryloxy ethyl) isocyanurate, .epsilon.-caprolactone-modified tris ((meth) acryloxy ethyl) isocyanurate, tris ((meth) acryloxy ethyl) isocyanurate.

  As the maleimide compound, those containing at least two maleimide groups in the molecule are preferable. For example, 1-methyl-2,4-bismaleimidebenzene, N, N′-m-phenylenebismaleimide, N, N ′ -P-phenylene bismaleimide, N, N'-m-toluylene bismaleimide, N, N'-4,4-biphenylene bismaleimide, N, N'-4,4- (3,3'-dimethyl-biphenylene ) Bismaleimide, N, N′-4,4- (3,3′-dimethyldiphenylmethane) bismaleimide, N, N′-4,4- (3,3′-diethyldiphenylmethane) bismaleimide, N, N ′ -4,4-diphenylmethane bismaleimide, N, N'-4,4-diphenylpropane bismaleimide, N, N'-4,4-diphenyl ether bisma Imido, N, N′-3,3′-diphenylsulfone bismaleimide, 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 -Cyclohexyl] benzene, 2,2-bis [4- (4-maleimidophenoxy) phenyl] hexafluoropropane and the like. These may be used alone or in combination of two or more, or may be used in combination with allyl compounds such as allylphenol, allylphenyl ether, and allyl benzoate.

  Such radically polymerizable compounds can be used alone or in combination of two or more. The radical polymerizable compound preferably contains at least a radical polymerizable compound having a viscosity at 25 ° C. of 100,000 to 1,000,000 mPa · s, and particularly a radical polymerizable compound having a viscosity (25 ° C.) of 100,000 to 500,000 mPa · s. It is preferable to contain. The viscosity of the radical polymerizable compound can be measured using a commercially available E-type viscometer.

  Among the radical polymerizable compounds, urethane (meth) acrylate is preferable from the viewpoint of adhesiveness, and after crosslinking with an organic peroxide used for improving heat resistance, radical polymerization showing Tg of 100 ° C. or more alone. It is particularly preferable to use the active compound in combination. As such a radically polymerizable compound, a compound having a dicyclopentenyl group, a tricyclodecanyl group and / or a triazine ring can be used. In particular, a radical polymerizable compound having a tricyclodecanyl group or a triazine ring is preferably used.

  When 0.1 to 10% by mass of a radically polymerizable compound having a phosphate ester structure is used, the adhesive strength on the surface of an inorganic substance such as a metal is preferably increased, and more preferably 0.5 to 5% by mass. The radically polymerizable compound having a phosphoric ester structure is obtained as a reaction product of phosphoric anhydride and 2-hydroxyl (meth) acrylate. Specific examples include 2-methacryloyloxyethyl acid phosphate, 2-acryloyloxyethyl acid phosphate, and the like. These can be used singly or in combination of two or more.

  Examples of the curing agent include imidazole, hydrazide, boron trifluoride-amine complex, sulfonium salt, amine imide, polyamine salt, dicyandiamide and the like. These can be used individually by 1 type or in mixture of 2 or more types, You may mix and use a decomposition accelerator, an inhibitor, etc. In addition, those encapsulating these curing agents with polyurethane-based or polyester-based polymeric substances and the like and microencapsulated are preferable because the pot life is extended.

  The curing agent preferably contains a radical polymerization initiator (radical polymerization initiator) that generates free radicals by heating or light.

  The radical polymerization initiator is one that decomposes by heating a peroxide compound, an azo compound or the like to generate free radicals, and is appropriately selected depending on the target connection temperature, connection time, pot life, etc. From the standpoint of properties and pot life, an organic peroxide 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 is preferred. In this case, the blending amount of the radical polymerization initiator is preferably 0.05 to 10% by mass and more preferably 0.1 to 5% by mass with respect to the entire solid content of the adhesive component.

  Specifically, the radical polymerization initiator can be selected from diacyl peroxide, peroxydicarbonate, peroxyester, peroxyketal, dialkyl peroxide, hydroperoxide, and the like. In order to suppress corrosion of connection terminals (circuit electrodes) of circuit members, it is preferable to select from peroxyesters, dialkyl peroxides, and hydroperoxides, and to select from peroxyesters that provide high reactivity. More preferred.

  Examples of the diacyl peroxide include isobutyl peroxide, 2,4-dichlorobenzoyl peroxide, 3,5,5-trimethylhexanoyl peroxide, octanoyl peroxide, lauroyl peroxide, stearoyl peroxide, and succinic peroxide. Benzoylperoxytoluene, benzoyl peroxide, etc.

  Examples of peroxydicarbonate include di-n-propyl peroxydicarbonate, diisopropyl peroxydicarbonate, bis (4-tert-butylcyclohexyl) peroxydicarbonate, di-2-ethoxymethoxyperoxydicarbonate, Examples include di (2-ethylhexylperoxy) dicarbonate, dimethoxybutylperoxydicarbonate, di (3-methyl-3-methoxybutylperoxy) dicarbonate, and the like.

  Examples of peroxyesters include cumylperoxyneodecanoate, 1,1,3,3-tetramethylbutylperoxyneodecanoate, 1-cyclohexyl-1-methylethylperoxynoedecanoate, tert -Hexylperoxyneodecanoate, tert-butylperoxypivalate, 1,1,3,3-tetramethylbutylperoxy-2-ethylhexanoate, 2,5-dimethyl-2,5-bis ( 2-ethylhexanoylperoxy) hexane, 1-cyclohexyl-1-methylethylperoxy-2-ethylhexanoate, tert-hexylperoxy-2-ethylhexanoate, tert-butylperoxy-2-ethyl Hexanonate, tert-butyl peroxyisobutyrate, 1,1-bis tert-butylperoxy) cyclohexane, tert-hexylperoxyisopropyl monocarbonate, tert-butylperoxy-3,5,5-trimethylhexanonate, tert-butylperoxylaurate, 2,5-dimethyl-2, 5-bis (m-toluoylperoxy) hexane, tert-butylperoxyisopropyl monocarbonate, tert-butylperoxy-2-ethylhexyl monocarbonate, tert-hexylperoxybenzoate, tert-butylperoxyacetate, di- Examples include tert-butyl peroxyhexahydroterephthalate.

  Examples of the peroxyketal include 1,1-bis (t-hexylperoxy) -3,5,5-trimethylcyclohexane, 1,1-bis (t-hexylperoxy) cyclohexane, 1,1-bis ( tert-Butylperoxy) -3,5,5-trimethylcyclohexane, 1,1- (tert-butylperoxy) cyclododecane, 2,2-bis (tert-butylperoxy) decane and the like.

  Examples of the dialkyl peroxide include α, α′-bis (tert-butylperoxy) diisopropylbenzene, dicumyl peroxide, 2,5-dimethyl-2,5-di (tert-butylperoxy) hexane, tert -Butyl cumyl peroxide

  Examples of the hydroperoxide include diisopropylbenzene hydroperoxide and cumene hydroperoxide.

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

  The adhesive component may appropriately contain a polymerization inhibitor such as hydroquinone or methyl ether hydroquinone as necessary.

  The adhesive film of the present invention is preferably used in the form of a film because of its excellent handleability. In that case, the adhesive film may contain a film-forming polymer. As film-forming polymers, polystyrene, polyethylene, polyvinyl butyral, polyvinyl formal, polyimide, polyamide, polyester, polyvinyl chloride, polyphenylene oxide, urea resin, melamine resin, phenol resin, xylene resin, epoxy resin, polyisocyanate resin, Phenoxy resin, polyimide resin, polyester urethane resin or the like is used. Among these, a resin having a functional group such as a hydroxyl group is more preferable because adhesiveness can be improved. Also, those obtained by modifying these polymers with radically polymerizable functional groups can be used. These polymers preferably have a weight average molecular weight of 10,000 or more. Moreover, since mixing property will fall when a weight average molecular weight becomes 1000000 or more, it is preferable in it being less than 1 million.

  Furthermore, the adhesive component may contain fillers, softeners, accelerators, anti-aging agents, colorants, flame retardants, thixotropic agents, coupling agents, phenol resins, melamine resins, isocyanates, and the like. it can.

  When the filler is contained, it is preferable because connection reliability and the like can be improved. The filler can be used if its maximum diameter is less than the particle diameter of the conductive particles, and is preferably used in the range of 5 to 60% by volume with respect to the adhesive component. If it exceeds 60% by volume, the effect of improving reliability is saturated.

  As the coupling agent, a compound containing one or more groups selected from the group consisting of a vinyl group, an acrylic group, an amino group, an epoxy group, and an isocyanate group is preferable from the viewpoint of improving adhesiveness.

  The conductive adhesive layer and the insulating adhesive layer can include the above-described adhesive component, but it is preferable that at least some of the components of each layer are different.

  In addition, when separated into a layer containing a reactive resin and a layer containing a latent curing agent, or separated into a layer containing a curing agent that generates free radicals and a layer containing conductive particles, In addition to the effect of refinement, an effect of improving pot life can be obtained.

  The adhesive film of the present invention is useful, for example, as a material for bonding an IC chip and a substrate or bonding electric circuits.

  When obtaining a circuit connection pair using the adhesive film of the present invention, for example, the circuit connection adhesive film of the present invention is interposed between a pair of circuit members arranged opposite to each other, and the whole is heated and pressurized. Thus, the circuit members can be bonded to each other so that the circuit electrodes of the respective circuit members are electrically connected to each other, thereby obtaining a circuit connection body.

  The circuit connection body is interposed between the pair of circuit members opposed to each other and the pair of circuit members, and the circuit members are connected to each other so that the circuit electrodes of each circuit member are electrically connected to each other. A connecting portion to be bonded, and the connecting portion is made of a cured product of the adhesive film for circuit connection of the present invention.

  Examples of the circuit member include a chip component such as a semiconductor chip, a resistor chip, and a capacitor chip, and a substrate such as a printed board. These circuit members are usually provided with a large number of connection terminals (circuit electrodes).

  In the adhesive film, the adhesive melts and flows at the time of connection to obtain a connection between circuit electrodes facing each other, and then cures to maintain the connection. The fluidity of the adhesive is an important factor. When an adhesive film having a thickness of 35 μm and 5 mm × 5 mm is sandwiched between a glass plate having a thickness of 0.7 mm and 15 mm × 15 mm, and heating and pressing are performed at 170 ° C., 2 MPa, 10 seconds, the initial adhesive film The value of the fluidity (B) / (A) expressed using the area (A) of the main surface and the area (B) of the main surface after heating and pressing is 1.3 to 3.0. Preferably, it is 1.5 to 2.5. If it is less than 1.3, the fluidity is poor and there is a tendency that good connection cannot be obtained. If it exceeds 3.0, bubbles tend to be generated and the reliability tends to be poor.

  The elastic modulus at 40 ° C. after curing of the adhesive film is preferably 100 to 3000 MPa, and more preferably 500 to 2000 MPa.

  Hereinafter, the present invention will be described more specifically with reference to examples. However, the present invention is not limited to the following examples.

(Preparation of adhesive film)
As thermoplastic resins, 27 parts by mass of polyester urethane 1 (manufactured by Toyobo Co., Ltd., UR4125 (trade name)), 10 parts by mass of polyester urethane 2 (manufactured by Toyobo Co., Ltd., UR3500 (trade name)), and ethylene-acetic acid 7.5 parts by mass of vinyl copolymer (Mitsui / DuPont Polychemical Co., Ltd., EV40W (trade name)), radical polymerizable compound, acrylate (manufactured by Toagosei Co., Ltd., M-215 (trade name)) ) 16 parts by mass and 24 parts by mass of urethane acrylate (manufactured by Shin-Nakamura Chemical Co., Ltd., UA5500T (trade name)) were mixed to obtain a base resin.

  To the above base resin, perhexa 250 (2,5-dimethyl-2,5-bis (2-ethylhexanoylperoxy) hexane, Nippon Oil & Fats Co., Ltd., trade name) and HTP-65W as radical polymerization initiators. (Di-tert-butylperoxyhexahydroterephthalate, Kayaku Akzo Co., Ltd., trade name) were mixed at a mass ratio shown in Table 1 to adjust the adhesive component. 100 parts by volume of the obtained adhesive component was mixed with 8.3 parts by volume of Ni-plated polystyrene particles (average particle size: 3 μm) as conductive particles, coated on a 75 μm-thick PET film, and at 70 ° C. for 5 minutes. By drying, the film adhesive 1 in which the conductive adhesive layer with a film thickness of 4 μm was formed on the PET film was obtained.

  On the other hand, the above two types of radical polymerization initiators were mixed with the base resin at a mass ratio shown in Table 1, and the obtained adhesive component was applied onto a PET film having a thickness of 50 μm. By making it dry partially, the film adhesive 2 in which the 10-micrometer-thick insulating adhesive layer was formed on PET film was obtained.

  The film-like adhesives 1 and 2 are laminated so that the conductive adhesive layer and the insulating adhesive layer face each other and laminated using a laminator (50 ° C., 50 cm / min). Example 1 and Comparative Example 1 And 2 adhesive films were obtained.

(Preparation of evaluation connector)
Each of these adhesive films was cut out to a size of 1.5 mm in width, and while being peeled off one separator (PET film), it was affixed to a glass substrate having an ITO electrode and an Al electrode at 70 ° C., 1 MPa, and 2 s. Then, after peeling off the other separator, COF (interelectrode pitch: 25 μm, electrode width: 12.2 μm, 12.8 μm) was applied, and pressure bonding was performed under conditions of 150 ° C. or 190 ° C., 3 MPa, 4 seconds, A connection body for evaluation was produced.

(Evaluation of connection resistance)
About each obtained connection body, the resistance value between adjacent electrodes is measured using a digital multimeter (manufactured by ADVANTEST, trade name), and when the average value is less than 3Ω, “A” and when it is 3Ω or more, “B ".

(Evaluation of indentation strength)
About each obtained connection body, the case where intensity | strength was sufficient and there was no nonuniformity was evaluated as "A", and the case where intensity | strength was weak or nonuniformity was evaluated as "B". The evaluation results are shown in Table 2.

  As shown in Table 2, in Comparative Examples 1 and 2 in which the masses of the radical polymerization initiators contained in the conductive adhesive layer and the insulating adhesive layer are equal, the connection resistance is obtained when pressure bonding is performed at 150 ° C. or 190 ° C. The indentation strength became insufficient. On the other hand, in Example 1 where the mass of the radical polymerization initiator contained in the conductive adhesive layer is less than the mass of the radical polymerization initiator contained in the insulating adhesive layer, either 150 ° C. or 190 ° C. Even when crimped, sufficiently low connection resistance and sufficient indentation strength were obtained.

  The adhesive film for circuit connection of the present invention is suitably used as a circuit connection material for connecting high-definition circuit members such as TCP, COF, and printed wiring boards.

  3a ... insulating adhesive layer, 3b ... conductive adhesive layer, 4a, 4b ... adhesive component, 5 ... conductive particles, 10 ... adhesive film for circuit connection.

Claims (4)

An adhesive film for circuit connection comprising: an adhesive component containing a curing agent and a conductive adhesive layer containing conductive particles; and an insulating adhesive layer containing an adhesive component containing a curing agent and no conductive particles Because
The thickness of the conductive adhesive layer is not more than twice the average particle size of the conductive particles,
The mass ratio of the curing agent contained in the adhesive component contained in the conductive adhesive layer to the adhesive component is relative to the adhesive component of the curing agent contained in the adhesive component contained in the insulating adhesive layer. An adhesive film for circuit connection, which is less than the mass ratio.   The adhesive film for circuit connection according to claim 1, wherein the adhesive component further contains a thermoplastic resin and a radical polymerizable compound, and the curing agent is a radical polymerization initiator. A pair of circuit members disposed opposite to each other;
A circuit connection body comprising a connection part interposed between the pair of circuit members and bonding the circuit members so that circuit electrodes of the respective circuit members are electrically connected to each other;
The circuit connection body which the said connection part consists of the hardened | cured material of the adhesive film for circuit connections of Claim 1 or 2. A pair of circuit members disposed opposite to each other, and a connection portion that is interposed between the pair of circuit members and bonds the circuit members to each other so that circuit electrodes of the respective circuit members are electrically connected; A method of manufacturing a circuit connection body comprising:
The connection made of a cured product of the adhesive film for circuit connection by interposing the adhesive film for circuit connection according to claim 1 or 2 between the pair of circuit members, and heating and pressurizing the whole. A method for manufacturing the circuit connection body, wherein a portion is provided.

Images