WO2016088664A1 - Electroconductive paste, connection structure, and method for manufacturing connection structure - Google Patents

Electroconductive paste, connection structure, and method for manufacturing connection structure Download PDF

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Publication number
WO2016088664A1
WO2016088664A1 PCT/JP2015/083349 JP2015083349W WO2016088664A1 WO 2016088664 A1 WO2016088664 A1 WO 2016088664A1 JP 2015083349 W JP2015083349 W JP 2015083349W WO 2016088664 A1 WO2016088664 A1 WO 2016088664A1
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WIPO (PCT)
Prior art keywords
electrode
solder
conductive paste
connection
target member
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PCT/JP2015/083349
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French (fr)
Japanese (ja)
Inventor
石澤　英亮
伸也 上野山
Original Assignee
積水化学工業株式会社
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Application filed by 積水化学工業株式会社 filed Critical 積水化学工業株式会社
Priority to CN201580057986.9A priority Critical patent/CN107148653B/en
Priority to KR1020167031969A priority patent/KR102431084B1/en
Priority to JP2015558297A priority patent/JP6067149B2/en
Publication of WO2016088664A1 publication Critical patent/WO2016088664A1/en

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    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01B—CABLES; CONDUCTORS; INSULATORS; SELECTION OF MATERIALS FOR THEIR CONDUCTIVE, INSULATING OR DIELECTRIC PROPERTIES
    • H01B1/00—Conductors or conductive bodies characterised by the conductive materials; Selection of materials as conductors
    • H01B1/20—Conductive material dispersed in non-conductive organic material
    • H01B1/22—Conductive material dispersed in non-conductive organic material the conductive material comprising metals or alloys
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01B—CABLES; CONDUCTORS; INSULATORS; SELECTION OF MATERIALS FOR THEIR CONDUCTIVE, INSULATING OR DIELECTRIC PROPERTIES
    • H01B5/00—Non-insulated conductors or conductive bodies characterised by their form
    • H01B5/16—Non-insulated conductors or conductive bodies characterised by their form comprising conductive material in insulating or poorly conductive material, e.g. conductive rubber
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
    • H01L24/00—Arrangements for connecting or disconnecting semiconductor or solid-state bodies; Methods or apparatus related thereto
    • H01L24/01—Means for bonding being attached to, or being formed on, the surface to be connected, e.g. chip-to-package, die-attach, "first-level" interconnects; Manufacturing methods related thereto
    • H01L24/10—Bump connectors ; Manufacturing methods related thereto
    • H01L24/11—Manufacturing methods
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01R—ELECTRICALLY-CONDUCTIVE CONNECTIONS; STRUCTURAL ASSOCIATIONS OF A PLURALITY OF MUTUALLY-INSULATED ELECTRICAL CONNECTING ELEMENTS; COUPLING DEVICES; CURRENT COLLECTORS
    • H01R4/00—Electrically-conductive connections between two or more conductive members in direct contact, i.e. touching one another; Means for effecting or maintaining such contact; Electrically-conductive connections having two or more spaced connecting locations for conductors and using contact members penetrating insulation
    • H01R4/04—Electrically-conductive connections between two or more conductive members in direct contact, i.e. touching one another; Means for effecting or maintaining such contact; Electrically-conductive connections having two or more spaced connecting locations for conductors and using contact members penetrating insulation using electrically conductive adhesives
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01R—ELECTRICALLY-CONDUCTIVE CONNECTIONS; STRUCTURAL ASSOCIATIONS OF A PLURALITY OF MUTUALLY-INSULATED ELECTRICAL CONNECTING ELEMENTS; COUPLING DEVICES; CURRENT COLLECTORS
    • H01R43/00—Apparatus or processes specially adapted for manufacturing, assembling, maintaining, or repairing of line connectors or current collectors or for joining electric conductors
    • H—ELECTRICITY
    • H05—ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR
    • H05K—PRINTED CIRCUITS; CASINGS OR CONSTRUCTIONAL DETAILS OF ELECTRIC APPARATUS; MANUFACTURE OF ASSEMBLAGES OF ELECTRICAL COMPONENTS
    • H05K3/00—Apparatus or processes for manufacturing printed circuits
    • H05K3/30—Assembling printed circuits with electric components, e.g. with resistor
    • H05K3/32—Assembling printed circuits with electric components, e.g. with resistor electrically connecting electric components or wires to printed circuits
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
    • H01L2224/00—Indexing scheme for arrangements for connecting or disconnecting semiconductor or solid-state bodies and methods related thereto as covered by H01L24/00
    • H01L2224/01—Means for bonding being attached to, or being formed on, the surface to be connected, e.g. chip-to-package, die-attach, "first-level" interconnects; Manufacturing methods related thereto
    • H01L2224/10—Bump connectors; Manufacturing methods related thereto
    • H01L2224/11—Manufacturing methods
    • H01L2224/115—Manufacturing methods by chemical or physical modification of a pre-existing or pre-deposited material
    • H01L2224/1152—Self-assembly, e.g. self-agglomeration of the bump material in a fluid

Definitions

  • the present invention relates to a conductive paste containing solder particles.
  • the present invention also relates to a connection structure using the conductive paste and a method for manufacturing the connection structure.
  • Anisotropic conductive materials such as anisotropic conductive paste and anisotropic conductive film are widely known.
  • anisotropic conductive material conductive particles are dispersed in a binder resin.
  • the anisotropic conductive material may be connected between a flexible printed circuit board and a glass substrate (FOG (Film on Glass)), or connected between a semiconductor chip and a flexible printed circuit board (COF ( (Chip on Film)), connection between a semiconductor chip and a glass substrate (COG (Chip on Glass)), connection between a flexible printed circuit board and a glass epoxy substrate (FOB (Film on Board)), and the like.
  • FOG Glass
  • COF Chip on Film
  • an anisotropic conductive material containing conductive particles is disposed on the glass epoxy substrate. To do.
  • a flexible printed circuit board is laminated, and heated and pressurized. As a result, the anisotropic conductive material is cured, and the electrodes are electrically connected via the conductive particles to obtain a connection structure.
  • Patent Document 1 includes a resin layer containing a thermosetting resin, solder powder, and a curing agent, and the solder powder and the curing agent include the resin layer.
  • An adhesive tape present therein is disclosed. This adhesive tape is in the form of a film, not a paste.
  • Patent Document 1 discloses a bonding method using the above-mentioned adhesive tape. Specifically, a first substrate, an adhesive tape, a second substrate, an adhesive tape, and a third substrate are laminated in this order from the bottom to obtain a laminate. At this time, the first electrode provided on the surface of the first substrate is opposed to the second electrode provided on the surface of the second substrate. Moreover, the 2nd electrode provided in the surface of the 2nd board
  • Patent Document 2 discloses anisotropy that electrically connects a first electrode that is an electrode of a connection portion of a first electronic component and a second electrode that is an electrode of a connection portion of a second electronic component.
  • a conductive adhesive is disclosed.
  • the anisotropic conductive adhesive includes an insulating polymer resin, bonding particles, and spacer particles. The joining particles are melted by heat generated by ultrasonic waves applied to the anisotropic conductive adhesive.
  • the spacer particles have a higher melting point than the bonding particles. Examples of the bonding particles include solder particles.
  • the adhesive tape described in Patent Document 1 is a film, not a paste. For this reason, it is difficult to efficiently arrange the solder powder on the electrodes (lines). For example, in the adhesive tape described in Patent Document 1, a part of the solder powder is easily placed in a region (space) where no electrode is formed. Solder powder disposed in a region where no electrode is formed does not contribute to conduction between the electrodes.
  • the solder powder may not be efficiently disposed on the electrodes (lines). Furthermore, when an anisotropic conductive paste containing solder powder is used, the gap between the electrodes tends to vary after the conductive connection. Further, even with the adhesive described in Patent Document 2, bonding particles such as solder particles may not be efficiently arranged on the electrodes (lines). Further, as described in Patent Document 2, even when spacer particles are used separately from bonding particles such as solder particles, the bonding particles may not be efficiently arranged on the electrodes (lines).
  • An object of the present invention is to provide a conductive paste that can control the interval between the electrodes with high accuracy, can further efficiently arrange the solder particles on the electrodes, and can improve the conduction reliability between the electrodes. Is to provide. Moreover, this invention is providing the manufacturing method of the connection structure and connection structure using the said electrically conductive paste.
  • the first connection target member having the first electrode on the surface and the second connection target member having the second electrode on the surface are connected, and the first electrode and the A conductive paste used to electrically connect a second electrode, comprising a thermosetting component, a plurality of solder particles, and a plurality of spacers having a melting point of 250 ° C. or higher, A conductive paste having an average particle size larger than the average particle size of the solder particles is provided.
  • the spacer is an insulating particle.
  • the conductive paste is used so that the spacer is in contact with both the first connection target member and the second connection target member.
  • the conductive paste has a temperature equal to or higher than the melting point of the solder particles and the thermosetting property when electrically connecting the first electrode and the second electrode. It is used by heating above the curing temperature of the components to aggregate and integrate the plurality of solder particles.
  • the ratio of the average particle diameter of the spacer to the average particle diameter of the solder particles is 1.1 or more and 15 or less.
  • the content of the spacer is 0.1 wt% or more and 10 wt% or less.
  • the solder particles have an average particle diameter of 1 ⁇ m or more and 40 ⁇ m or less.
  • the content of the solder particles is 10% by weight or more and 80% by weight or less.
  • the ratio of the content of the solder particles in wt% to the content of the spacer in wt% is 2 or more and 100 or less.
  • a first connection target member having at least one first electrode on the surface
  • a second connection target member having at least one second electrode on the surface
  • the first connection target member and the connection part connecting the second connection target member, and the material of the connection part is the conductive paste described above
  • the first electrode and the second electrode Are electrically connected by a solder portion in the connection portion, and the spacer is in contact with both the first connection target member and the second connection target member.
  • the first connection target member and the second connection target member are disposed so as to face each other, and by heating the conductive paste to a temperature equal to or higher than the melting point of the solder particles and equal to or higher than the curing temperature of the thermosetting component.
  • connection object member and the second And a step of contacting the spacers to both the connection target member, the manufacturing method of the connecting structure is provided.
  • thermosetting component is equal to or higher than the melting point of the solder particles. Is heated to a temperature equal to or higher than the curing temperature, and a plurality of the solder particles are aggregated and integrated.
  • connection portion in the step of arranging the second connection target member and the step of forming the connection portion, no pressure is applied, and the conductive paste includes The weight of the second connection target member is added.
  • the second connection target member is a resin film, a flexible printed board, a flexible flat cable, or a rigid flexible board.
  • the conductive paste according to the present invention includes a thermosetting component, a plurality of solder particles, and a plurality of spacers having a melting point of 250 ° C. or higher, the first connection target member having the first electrode on the surface thereof, When the second connection target member having the second electrode on the surface is connected and the first electrode and the second electrode are electrically connected, the interval between the electrodes is controlled with high accuracy.
  • the solder particles can be efficiently disposed on the electrodes, and the conduction reliability between the electrodes can be improved.
  • FIG. 1 is a cross-sectional view schematically showing a connection structure obtained using a conductive paste according to an embodiment of the present invention.
  • 2A to 2C are cross-sectional views for explaining each step of an example of a method for manufacturing a connection structure using the conductive paste according to the embodiment of the present invention.
  • FIG. 3 is a cross-sectional view showing a modification of the connection structure.
  • FIG. 4 is a cross-sectional view showing a modification of the connection structure.
  • the conductive paste according to the present invention connects the first connection target member having the first electrode on the surface and the second connection target member having the second electrode on the surface, and the first electrode and the first electrode Used to electrically connect the two electrodes.
  • the conductive paste according to the present invention includes a thermosetting component, a plurality of solder particles, and a plurality of spacers having a melting point of 250 ° C. or higher.
  • the average particle size of the spacer is larger than the average particle size of the solder particles.
  • the distance between the electrodes can be controlled with high accuracy when the electrodes are electrically connected. Furthermore, since the space between the upper and lower electrodes is sufficiently secured by the spacer when the solder particles gather between the electrodes, the plurality of solder particles are likely to gather between the upper and lower opposing electrodes, and the plurality of solder particles are separated into electrodes (lines). Can be efficiently placed on top. Moreover, it is difficult for some of the plurality of solder particles to be disposed in a region (space) where no electrode is formed, and the amount of solder particles disposed in a region where no electrode is formed can be considerably reduced. Therefore, the conduction reliability between the electrodes can be improved.
  • a solder particle can be efficiently arrange
  • the use of a spacer having a specific average particle size greatly contributes to improvement in the amount of solder and the placement accuracy between the upper and lower electrodes to be connected.
  • the solder particles move between the first connection target member and the second connection target member when the solder particles move on the electrode.
  • interval which can move is ensured and the movement of a solder particle is accelerated
  • the conduction reliability between the electrodes increases.
  • the use of a spacer not only regulates the distance between the upper and lower electrodes, but also contributes to increasing the cohesiveness of the solder particles.
  • the present invention it is possible to prevent displacement between the electrodes.
  • the alignment of the electrode of the first connection target member and the electrode of the second connection target member is performed. Even when the first connection target member and the second connection target member are overlapped in a shifted state, the shift is corrected and the electrodes of the first connection target member and the second connection target member are corrected. Can be connected (self-alignment effect).
  • the conductive particles are not formed on the electrodes. Since it becomes difficult to gather and the solder bonding property between the conductive particles is low, the conductive particles that have moved onto the electrode are likely to move out of the electrode. For this reason, the effect of suppressing the displacement between the electrodes is also reduced.
  • the viscosity ( ⁇ 25) at 25 ° C. of the conductive paste is preferably 10 Pa ⁇ s or more, more preferably 50 Pa ⁇ s or more, and further preferably 100 Pa ⁇ s or more. , Preferably 800 Pa ⁇ s or less, more preferably 600 Pa ⁇ s or less, and even more preferably 500 Pa ⁇ s or less.
  • the viscosity ( ⁇ 25) can be adjusted as appropriate to the type and amount of the compounding ingredients. Further, the use of a filler can make the viscosity relatively high.
  • the viscosity ( ⁇ 25) can be measured using, for example, an E-type viscometer (manufactured by Toki Sangyo Co., Ltd.) and the like at 25 ° C. and 5 rpm.
  • the conductive paste according to the present invention can be suitably used for a connection structure according to the present invention described later and a method for manufacturing the connection structure.
  • the conductive paste has a temperature equal to or higher than the melting point of the solder particles and the thermosetting component when electrically connecting the first electrode and the second electrode. It is preferable that the plurality of solder particles are aggregated and integrated by heating to a temperature higher than the curing temperature. By integrating the plurality of solder particles, a solder area with a larger area is formed. In one solder part, two or more solder particles in the conductive paste are preferably integrated, more preferably three or more solder particles in the conductive paste are integrated, and five or more in the conductive paste More preferably, the solder particles are integrated.
  • the conductive paste is preferably used for electrical connection of electrodes.
  • the conductive paste is preferably a circuit connection material.
  • solder particles have solder on a conductive outer surface. As for the said solder particle, both a center part and an electroconductive outer surface are formed with the solder.
  • the solder particles are particles in which both the central portion of the solder particles and the conductive outer surface are solder.
  • the zeta potential on the surface of the solder particles is positive.
  • the zeta potential of the surface of the solder particle may not be positive.
  • Zeta potential measurement method 0.05 g of solder particles are put in 10 g of methanol and subjected to ultrasonic treatment or the like to uniformly disperse to obtain a dispersion. Using this dispersion and using “Delsamax PRO” manufactured by Beckman Coulter, the zeta potential can be measured at 23 ° C. by electrophoretic measurement.
  • the zeta potential of the solder particles is preferably 0 mV or more, more preferably more than 0 mV, preferably 10 mV or less, more preferably 5 mV or less, even more preferably 1 mV or less, still more preferably 0.7 mV or less, particularly preferably 0.5 mV. It is as follows. When the zeta potential is less than or equal to the above upper limit, the solder particles hardly aggregate in the conductive paste before use. When the zeta potential is 0 mV or more, the solder particles efficiently aggregate on the electrode during mounting.
  • the solder particles preferably have a solder particle body and an anionic polymer disposed on the surface of the solder particle body.
  • the solder particles are preferably obtained by surface-treating the solder particle body with an anionic polymer or a compound that becomes an anionic polymer.
  • the solder particles are preferably a surface treated product of an anion polymer or a compound that becomes an anion polymer.
  • the said anion polymer and the compound used as the said anion polymer only 1 type may respectively be used and 2 or more types may be used together.
  • an anionic polymer for example, a (meth) acrylic polymer copolymerized with (meth) acrylic acid, synthesized from a dicarboxylic acid and a diol and having carboxyl groups at both ends
  • Polyester polymer polymer obtained by intermolecular dehydration condensation reaction of dicarboxylic acid and having carboxyl groups at both ends, polyester polymer synthesized from dicarboxylic acid and diamine and having carboxyl groups at both ends, and modified poval having carboxyl groups ( A method of reacting a carboxyl group of an anionic polymer with a hydroxyl group on the surface of a solder particle body using “GOHSEX T” manufactured by Nippon Synthetic Chemical Co., Ltd., etc.
  • anion portion of the anionic polymer examples include the carboxyl group, and other than that, a tosyl group (p—H 3 CC 6 H 4 S ( ⁇ O) 2 —), a sulfonate ion group (—SO 3 —) ), And phosphate ion groups (—PO 4 ⁇ ) and the like.
  • a compound having a functional group that reacts with a hydroxyl group on the surface of the solder particle body and having a functional group that can be polymerized by addition or condensation reaction is used.
  • the method of polymerizing on the surface is mentioned.
  • the functional group that reacts with the hydroxyl group on the surface of the solder particle body include a carboxyl group and an isocyanate group.
  • the functional group that polymerizes by addition and condensation reactions include a hydroxyl group, a carboxyl group, an amino group, and (meth).
  • An acryloyl group is mentioned.
  • the weight average molecular weight of the anionic polymer is preferably 2000 or more, more preferably 3000 or more, preferably 10,000 or less, more preferably 8000 or less.
  • the weight average molecular weight is not less than the above lower limit and not more than the above upper limit, it is easy to dispose an anionic polymer on the surface of the solder particle body, and it is easy to make the zeta potential on the surface of the solder particle positive.
  • the solder particles can be arranged on the electrodes even more efficiently.
  • the weight average molecular weight indicates a weight average molecular weight in terms of polystyrene measured by gel permeation chromatography (GPC).
  • the weight average molecular weight of the polymer obtained by surface-treating the solder particle body with a compound that becomes an anionic polymer is obtained by dissolving the solder in the solder particles and removing the solder particles with dilute hydrochloric acid or the like that does not cause decomposition of the polymer. It can be determined by measuring the weight average molecular weight of the remaining polymer.
  • the solder is preferably a metal (low melting point metal) having a melting point of 450 ° C. or lower.
  • the solder particles are preferably metal particles (low melting point metal particles) having a melting point of 450 ° C. or lower.
  • the low melting point metal particles are particles containing a low melting point metal.
  • the low melting point metal is a metal having a melting point of 450 ° C. or lower.
  • the melting point of the low melting point metal is preferably 300 ° C. or lower, more preferably 160 ° C. or lower.
  • the solder particles include tin.
  • the content of tin is preferably 30% by weight or more, more preferably 40% by weight or more, still more preferably 70% by weight or more, and particularly preferably 90% by weight or more.
  • the content of tin in the solder particles is equal to or higher than the lower limit, the connection reliability between the solder portion and the electrode is further enhanced.
  • the tin content is determined using a high-frequency inductively coupled plasma emission spectrometer (“ICP-AES” manufactured by Horiba, Ltd.) or a fluorescent X-ray analyzer (“EDX-800HS” manufactured by Shimadzu). It can be measured.
  • ICP-AES high-frequency inductively coupled plasma emission spectrometer
  • EDX-800HS fluorescent X-ray analyzer
  • solder particles By using the above solder particles, the solder is melted and joined to the electrodes, and the solder portion conducts between the electrodes. For example, since the solder portion and the electrode are not in point contact but in surface contact, the connection resistance is lowered. In addition, the use of solder particles increases the bonding strength between the solder portion and the electrode. As a result, peeling between the solder portion and the electrode is further less likely to occur, and the conduction reliability and the connection reliability are effectively increased.
  • the metal (low melting point metal) constituting the solder particles is not particularly limited.
  • the low melting point metal is preferably tin or an alloy containing tin.
  • the alloy include a tin-silver alloy, a tin-copper alloy, a tin-silver-copper alloy, a tin-bismuth alloy, a tin-zinc alloy, and a tin-indium alloy.
  • the low melting point metal is preferably tin, tin-silver alloy, tin-silver-copper alloy, tin-bismuth alloy, or tin-indium alloy because of its excellent wettability to the electrode. More preferred are a tin-bismuth alloy and a tin-indium alloy.
  • the solder particles are preferably a filler material having a liquidus line of 450 ° C. or lower based on JIS Z3001: Welding terms.
  • the composition of the solder particles include metal compositions containing zinc, gold, silver, lead, copper, tin, bismuth, indium and the like.
  • the solder particles include nickel, copper, antimony, aluminum, zinc, iron, gold, titanium, phosphorus, germanium, tellurium, cobalt, bismuth, manganese, chromium. Further, it may contain a metal such as molybdenum and palladium. Moreover, from the viewpoint of further increasing the bonding strength between the solder portion and the electrode, the solder particles preferably contain nickel, copper, antimony, aluminum, or zinc. From the viewpoint of further increasing the bonding strength between the solder part and the electrode, the content of these metals for increasing the bonding strength is preferably 0.0001% by weight or more, preferably 1% by weight in 100% by weight of the solder particles. % Or less.
  • the average particle size of the solder particles is preferably 0.5 ⁇ m or more, more preferably 1 ⁇ m or more, still more preferably 3 ⁇ m or more, particularly preferably 5 ⁇ m or more, preferably 100 ⁇ m or less, more preferably less than 80 ⁇ m, still more preferably 75 ⁇ m.
  • it is more preferably 60 ⁇ m or less, even more preferably 40 ⁇ m or less, still more preferably 30 ⁇ m or less, still more preferably 20 ⁇ m or less, particularly preferably 15 ⁇ m or less, and most preferably 10 ⁇ m or less.
  • the average particle diameter of the solder particles is particularly preferably 3 ⁇ m or more and 30 ⁇ m or less.
  • the average particle diameter” of the solder particles indicates the number average particle diameter.
  • the average particle diameter of the solder particles is obtained, for example, by observing 50 arbitrary solder particles with an electron microscope or an optical microscope, calculating an average value, or performing laser diffraction particle size distribution measurement.
  • the coefficient of variation of the particle diameter of the solder particles is preferably 5% or more, more preferably 10% or more, preferably 40% or less, more preferably 30% or less.
  • the variation coefficient of the particle diameter is not less than the above lower limit and not more than the above upper limit, the solder particles can be more efficiently arranged on the electrode.
  • the coefficient of variation of the particle diameter of the solder particles may be less than 5%.
  • CV value (%) ( ⁇ / Dn) ⁇ 100 ⁇ : Standard deviation of particle diameter of solder particles Dn: Average value of particle diameter of solder particles
  • the shape of the solder particles is not particularly limited.
  • the solder particles may have a spherical shape or a shape other than a spherical shape such as a flat shape.
  • the content of the solder particles in 100% by weight of the conductive paste is preferably 1% by weight or more, more preferably 2% by weight or more, still more preferably 10% by weight or more, particularly preferably 20% by weight or more, and most preferably 30%. % By weight or more, preferably 80% by weight or less, more preferably 60% by weight or less, and still more preferably 50% by weight or less.
  • the content of the solder particles is not less than the above lower limit and not more than the above upper limit, it is possible to more efficiently arrange the solder particles on the electrodes, and it is easy to arrange many solder particles between the electrodes, The conduction reliability is further increased. From the viewpoint of further improving the conduction reliability, it is preferable that the content of the solder particles is large.
  • the content of the solder particles is preferably 100% by weight of the conductive paste from the viewpoint of further improving the conduction reliability. Is 20% by weight or more, more preferably 30% by weight or more, preferably 55% by weight or less, more preferably 45% by weight or less.
  • the content of the solder particles is preferably 100% by weight of the conductive paste. Is 30% by weight or more, more preferably 40% by weight or more, preferably 70% by weight or less, more preferably 60% by weight or less.
  • the content of the solder particles is preferably 100% by weight of the conductive paste from the viewpoint of further improving the conduction reliability. Is 30% by weight or more, more preferably 40% by weight or more, preferably 70% by weight or less, more preferably 60% by weight or less.
  • the content of the solder particles is preferably 100% by weight of the conductive paste. Is 30% by weight or more, more preferably 40% by weight or more, preferably 70% by weight or less, more preferably 60% by weight or less.
  • the spacer is preferably used so as to contact both the first connection target member and the second connection target member. Therefore, the conductive paste according to the present invention is suitably used so that the spacer contacts both the first connection target member and the second connection target member.
  • the spacer includes the first electrode (region where the first electrode is provided) of the first connection target member and the second electrode (second electrode of the second connection target member). It is preferably used so as to be in contact with both the region and the region provided with.
  • the spacer is in contact with both a region where the first electrode of the first connection target member is not provided and a region where the second electrode of the second connection target member is not provided.
  • the spacer tends to move to a region where no electrode is provided due to the action of the solder trying to gather between the electrodes during the conductive connection.
  • the spacer may be disposed between the electrodes.
  • the melting point of the spacer is 250 ° C. or higher.
  • the melting point is set high so that the spacer does not melt when the first electrode and the second electrode are electrically connected.
  • the upper limit of the melting point of the spacer is not particularly limited.
  • the melting point of the spacer may be 400 ° C. or less.
  • the melting point of the spacer is preferably 300 ° C. or higher, more preferably 350 ° C. or higher.
  • the spacer may be resin particles.
  • the resin particle material include polyolefin resin, acrylic resin, phenol resin, melamine resin, benzoguanamine resin, urea resin, epoxy resin, unsaturated polyester resin, saturated polyester resin, polyethylene terephthalate, polysulfone, polyphenylene oxide, polyacetal, polyimide , Polyamideimide, polyetheretherketone, polyethersulfone, divinylbenzene polymer, and divinylbenzene copolymers such as vinylbenzene-styrene copolymer and divinylbenzene- (meth) acrylate copolymer It is done.
  • the material of the resin particles is a polymer obtained by polymerizing one or more polymerizable monomers having an ethylenically unsaturated group. Is preferred. In particular, divinylbenzene polymer, polyimide or polyamideimide is preferable.
  • examples of the material for the spacer include silica, glass, quartz, silicone, metal, and metal oxide.
  • the material of the spacer need not be a metal.
  • the material of the spacer is preferably a resin, and more preferably a divinylbenzene copolymer.
  • the divinylbenzene copolymer includes, for example, divinylbenzene as a copolymerization component.
  • the spacer is preferably an insulating particle from the viewpoint of further improving the insulation reliability.
  • the average particle size of the spacer is preferably 10 ⁇ m or more, more preferably 20 ⁇ m or more, still more preferably 25 ⁇ m or more, preferably 100 ⁇ m or less, more preferably 75 ⁇ m or less, and even more preferably 50 ⁇ m or less.
  • the average particle diameter of the spacer is not less than the above lower limit and not more than the above upper limit, the distance between the electrodes can be controlled with higher accuracy, and the solder particles can be arranged more efficiently on the electrodes.
  • the average particle diameter of the spacer indicates the number average particle diameter.
  • the average particle diameter of the spacers can be obtained, for example, by observing 50 arbitrary spacers with an electron microscope or an optical microscope, calculating an average value, or performing laser diffraction particle size distribution measurement.
  • the average particle diameter of the spacer is larger than the average particle diameter of the solder particles from the viewpoint of controlling between the electrodes with high accuracy and efficiently arranging the solder on the electrodes.
  • the ratio of the average particle diameter of the spacer to the average particle diameter of the solder particles is preferably 1.1 or more, more preferably 1.5 or more, still more preferably 2 or more, preferably 15 or less, more preferably 10 or less, still more preferably 8 or less.
  • the ratio of the average particle diameter of the spacer to the average particle diameter of the solder particles (average particle diameter of the spacer) / (Average particle diameter of solder particles) is preferably 1.0 or more, more preferably 1.5 or more, preferably 15 or less, more preferably 10 or less.
  • the coefficient of variation of the particle diameter of the spacer is preferably 3% or more, more preferably 5% or more, preferably 30% or less, more preferably 20% or less.
  • the variation coefficient of the particle diameter is not less than the lower limit and not more than the upper limit, the distance between the electrodes can be controlled with higher accuracy.
  • CV value (%) ( ⁇ / Dn) ⁇ 100 ⁇ : Standard deviation of the particle diameter of the spacer Dn: Average value of the particle diameter of the spacer
  • the content of the solder particles in units of% by weight (in 100% by weight of the conductive paste) of the spacer is preferably 2 or more, more preferably 5 or more, More preferably, it is 10 or more, preferably 100 or less, more preferably 80 or less, and still more preferably 70.
  • the 10% K value (compression elastic modulus when compressed to 10%) of the spacer is preferably 2000 N / mm 2 or more, more preferably 3500 N / mm 2 or more, preferably 8000 N / mm 2 or less, and more preferably not more than 6000 N / mm 2.
  • the 10% K value of the spacer is not less than the above lower limit and not more than the above upper limit, excessive movement of the spacer can be prevented after the spacer contacts both the first electrode and the second electrode. Aggregation of the solder particles is promoted, displacement between the first electrode and the second electrode can be prevented, and conduction reliability can be improved.
  • the 10% K value of the spacer can be measured as follows.
  • the spacer is compressed with a smooth indenter end face of a cylinder (diameter 50 ⁇ m, made of diamond) under conditions where a maximum test load of 90 mN is applied for 30 seconds.
  • the load value (N) and compression displacement (mm) at this time are measured. From the measured value obtained, the compression modulus can be obtained by the following formula.
  • the micro compression tester for example, “Fischer Scope H-100” manufactured by Fischer is used.
  • the compression recovery rate of the spacer is preferably 30% or more, more preferably 40% or more, preferably 80 % Or less, more preferably 70% or less. Moreover, after the spacer is in contact with both the first electrode and the second electrode, the spacer can be prevented from excessively moving after the compression recovery rate of the spacer is not less than the lower limit and not more than the upper limit. Aggregation of the solder particles is promoted, misalignment between the first electrode and the second electrode can be prevented, and conduction reliability can be improved.
  • the compression recovery rate can be measured as follows.
  • Compression recovery rate (%) [(L1-L2) / L1] ⁇ 100
  • L1 Compressive displacement from the origin load value to the reverse load value when applying a load
  • L2 Unloading displacement from the reverse load value to the origin load value when releasing the load
  • the content of the spacer is preferably 0.1% by weight or more, more preferably 0.5% by weight or more, still more preferably 1% by weight or more, preferably 10% by weight or less, more preferably. Is 5% by weight or less, more preferably 4% by weight or less, and particularly preferably 3% by weight or less.
  • the content of the spacer is not less than the above lower limit and not more than the above upper limit, the distance between the electrodes can be controlled with higher accuracy, and the solder particles can be arranged more efficiently on the electrodes. It is easy to arrange many solder particles, and the conduction reliability is further enhanced.
  • thermosetting compound thermosetting component
  • the thermosetting compound is a compound that can be cured by heating.
  • examples of the thermosetting compound include oxetane compounds, epoxy compounds, episulfide compounds, (meth) acrylic compounds, phenolic compounds, amino compounds, unsaturated polyester compounds, polyurethane compounds, silicone compounds, and polyimide compounds. From the viewpoint of further improving the curability and viscosity of the conductive paste and further improving the connection reliability, an epoxy compound is preferable.
  • the content of the thermosetting compound is preferably 20% by weight or more, more preferably 40% by weight or more, still more preferably 50% by weight or more, and preferably 99% by weight or less. Is 98% by weight or less, more preferably 90% by weight or less, and particularly preferably 80% by weight or less. From the viewpoint of further improving the impact resistance, it is preferable that the content of the thermosetting component is large.
  • thermosetting agent thermosetting component
  • the thermosetting agent thermosets the thermosetting compound.
  • examples of the thermosetting agent include imidazole curing agents, amine curing agents, phenol curing agents, polythiol curing agents and other thiol curing agents, acid anhydrides, thermal cation initiators (thermal cation curing agents), and thermal radical generators. It is done. As for the said thermosetting agent, only 1 type may be used and 2 or more types may be used together.
  • An imidazole curing agent, a thiol curing agent, or an amine curing agent is preferable because the conductive paste can be cured more rapidly at a low temperature. Moreover, since a storage stability becomes high when the curable compound curable by heating and the thermosetting agent are mixed, a latent curing agent is preferable.
  • the latent curing agent is preferably a latent imidazole curing agent, a latent thiol curing agent, or a latent amine curing agent.
  • the said thermosetting agent may be coat
  • the imidazole curing agent is not particularly limited, and 2-methylimidazole, 2-ethyl-4-methylimidazole, 1-cyanoethyl-2-phenylimidazole, 1-cyanoethyl-2-phenylimidazolium trimellitate, 2, 4-Diamino-6- [2'-methylimidazolyl- (1 ')]-ethyl-s-triazine and 2,4-diamino-6- [2'-methylimidazolyl- (1')]-ethyl-s- Examples include triazine isocyanuric acid adducts.
  • the thiol curing agent is not particularly limited, and examples thereof include trimethylolpropane tris-3-mercaptopropionate, pentaerythritol tetrakis-3-mercaptopropionate, and dipentaerythritol hexa-3-mercaptopropionate. .
  • the amine curing agent is not particularly limited, and hexamethylenediamine, octamethylenediamine, decamethylenediamine, 3,9-bis (3-aminopropyl) -2,4,8,10-tetraspiro [5.5].
  • examples include undecane, bis (4-aminocyclohexyl) methane, metaphenylenediamine, and diaminodiphenylsulfone.
  • thermal cation initiator examples include iodonium cation curing agents, oxonium cation curing agents, and sulfonium cation curing agents.
  • examples of the iodonium-based cationic curing agent include bis (4-tert-butylphenyl) iodonium hexafluorophosphate.
  • examples of the oxonium-based cationic curing agent include trimethyloxonium tetrafluoroborate.
  • sulfonium-based cationic curing agent examples include tri-p-tolylsulfonium hexafluorophosphate.
  • the thermal radical generator is not particularly limited, and examples thereof include azo compounds and organic peroxides.
  • examples of the azo compound include azobisisobutyronitrile (AIBN).
  • examples of the organic peroxide include di-tert-butyl peroxide and methyl ethyl ketone peroxide.
  • the reaction initiation temperature of the thermosetting agent is preferably 50 ° C or higher, more preferably 70 ° C or higher, still more preferably 80 ° C or higher, preferably 250 ° C or lower, more preferably 200 ° C or lower, still more preferably 150 ° C or lower, Especially preferably, it is 140 degrees C or less.
  • the reaction start temperature of the thermosetting agent is not less than the above lower limit and not more than the above upper limit, the solder particles are more efficiently arranged on the electrode.
  • the reaction initiation temperature of the thermosetting agent is particularly preferably 80 ° C. or higher and 140 ° C. or lower.
  • the reaction initiation temperature of the thermosetting agent is preferably higher than the melting point of the solder in the solder particles, more preferably 5 ° C. or more, more preferably 10 It is more preferable that the temperature is higher than ° C.
  • the reaction start temperature of the thermosetting agent means the temperature at which the exothermic peak of DSC starts to rise.
  • the content of the thermosetting agent is not particularly limited.
  • the content of the thermosetting agent is preferably 0.01 parts by weight or more, more preferably 1 part by weight or more, preferably 200 parts by weight or less, more preferably 100 parts by weight with respect to 100 parts by weight of the thermosetting compound. Part or less, more preferably 75 parts by weight or less.
  • the content of the thermosetting agent is at least the above lower limit, it is easy to sufficiently cure the conductive paste.
  • the content of the thermosetting agent is not more than the above upper limit, it is difficult for an excess thermosetting agent that did not participate in curing after curing to remain, and the heat resistance of the cured product is further enhanced.
  • the conductive paste preferably contains a flux.
  • the flux is not particularly limited.
  • a flux generally used for soldering or the like can be used.
  • the flux include zinc chloride, a mixture of zinc chloride and an inorganic halide, a mixture of zinc chloride and an inorganic acid, a molten salt, phosphoric acid, a derivative of phosphoric acid, an organic halide, hydrazine, an organic acid, and pine resin.
  • Etc As for the said flux, only 1 type may be used and 2 or more types may be used together.
  • Examples of the molten salt include ammonium chloride.
  • Examples of the organic acid include lactic acid, citric acid, stearic acid, glutamic acid, and glutaric acid.
  • Examples of the pine resin include activated pine resin and non-activated pine resin.
  • the flux is preferably an organic acid having two or more carboxyl groups, pine resin.
  • the flux may be an organic acid having two or more carboxyl groups, or pine resin.
  • the above rosins are rosins whose main component is abietic acid.
  • the flux is preferably rosins, and more preferably abietic acid. By using this preferable flux, the conduction reliability between the electrodes is further enhanced.
  • the active temperature (melting point) of the flux is preferably 50 ° C. or higher, more preferably 70 ° C. or higher, further preferably 80 ° C. or higher, preferably 200 ° C. or lower, more preferably 190 ° C. or lower, even more preferably 160 ° C. or lower. More preferably, it is 150 ° C. or less, and still more preferably 140 ° C. or less.
  • the activation temperature of the flux is preferably 80 ° C. or higher and 190 ° C. or lower.
  • the active temperature of the flux is particularly preferably 80 ° C. or higher and 140 ° C. or lower.
  • Examples of the flux having a melting point of 80 ° C. or higher and 190 ° C. or lower include succinic acid (melting point 186 ° C.), glutaric acid (melting point 96 ° C.), adipic acid (melting point 152 ° C.), pimelic acid (melting point 104 ° C.), suberic acid
  • Examples thereof include dicarboxylic acids such as (melting point 142 ° C.), benzoic acid (melting point 122 ° C.), and malic acid (melting point 130 ° C.).
  • the boiling point of the flux is preferably 200 ° C. or lower.
  • the melting point of the flux is preferably higher than the melting point of the solder in the solder particles, preferably 5 ° C or higher, more preferably 10 ° C or higher. Is more preferable.
  • the melting point of the flux is preferably higher than the reaction start temperature of the thermosetting agent, more preferably 5 ° C or higher, more preferably 10 ° C or higher. More preferably.
  • the solder particles can be efficiently aggregated on the electrode portion. This is because, when heat is applied at the time of joining, when the electrode formed on the connection target member is compared with the portion of the connection target member around the electrode, the thermal conductivity of the electrode portion is that of the connection target member portion around the electrode. Due to the fact that it is higher than the thermal conductivity, the temperature rise of the electrode portion is fast. At the stage where the melting point of the solder particles is exceeded, the inside of the solder particles dissolves, but the oxide film formed on the surface does not reach the melting point (activation temperature) of the flux and is not removed.
  • the flux may be dispersed in the conductive paste or may be adhered on the surface of the solder particles.
  • the flux is preferably a flux that releases cations by heating.
  • a flux that releases cations upon heating the solder particles can be arranged more efficiently on the electrode.
  • the content of the flux is preferably 0.5% by weight or more, preferably 30% by weight or less, more preferably 25% by weight or less.
  • the conductive paste may not contain a flux.
  • the flux content is not less than the above lower limit and not more than the above upper limit, it becomes more difficult to form an oxide film on the surface of the solder and the electrode, and the oxide film formed on the surface of the solder and the electrode is more effective. Can be removed.
  • a filler may be added to the conductive paste.
  • the filler may be an organic filler or an inorganic filler. By adding the filler, the distance at which the solder particles aggregate can be suppressed, and the solder particles can be uniformly aggregated on all the electrodes of the substrate.
  • the filler content is preferably 0% by weight or more, preferably 5% by weight or less, more preferably 2% by weight or less, and further preferably 1% by weight or less.
  • the content of the filler is not less than the above lower limit and not more than the above upper limit, the solder particles are more efficiently arranged on the electrode.
  • the conductive paste is, for example, a filler, an extender, a softener, a plasticizer, a polymerization catalyst, a curing catalyst, a colorant, an antioxidant, a heat stabilizer, a light stabilizer, an ultraviolet absorber, and a lubricant.
  • various additives such as an antistatic agent and a flame retardant may be included.
  • connection structure includes a first connection target member having at least one first electrode on the surface, a second connection target member having at least one second electrode on the surface, and the first The connection object member and the connection part which has connected the said 2nd connection object member are provided.
  • the connection portion is formed of the conductive paste described above, and is a cured product of the conductive paste described above.
  • the material of the connection portion is the conductive paste described above.
  • the first electrode and the second electrode are electrically connected by a solder portion in the connection portion. It is preferable that the spacer is in contact with both the first connection target member and the second connection target member.
  • the manufacturing method of the connection structure according to the present invention includes the step of disposing the conductive paste on the surface of the first connection target member having at least one first electrode on the surface using the conductive paste described above.
  • the second connection target member having at least one second electrode on the surface of the conductive paste opposite to the first connection target member side is provided with the first electrode and the second connection target.
  • the spacer is preferably brought into contact with both the first connection target member and the second connection target member.
  • connection structure according to the present invention since a specific conductive paste is used, a plurality of solder particles are likely to gather between the first electrode and the second electrode.
  • a plurality of solder particles can be efficiently arranged on the electrode (line).
  • thermosetting component when electrically connecting the first electrode and the second electrode, heating is performed at a temperature higher than the melting point of the solder particles and higher than the curing temperature of the thermosetting component. It is preferable that the plurality of solder particles are aggregated and integrated.
  • another method for efficiently collecting a plurality of solder particles between the electrodes may be further employed.
  • a method for efficiently collecting a plurality of solder particles between electrodes when heat is applied to the conductive paste between the first connection target member and the second connection target member, the viscosity of the conductive paste by heat is applied.
  • the method of generating the convection of the electrically conductive paste between a 1st connection object member and a 2nd connection object member etc. is mentioned because it falls.
  • a method of generating convection due to a difference in heat capacity between the electrode on the surface of the connection target member and the other surface member, a method of generating convection as water vapor from the heat of the connection target member, and the first Examples include a method of generating convection due to a temperature difference between the connection target member and the second connection target member.
  • a method of selectively aggregating solder particles on the surface of the electrode may be further employed.
  • a method of selectively agglomerating solder particles on the surface of the electrode there is a connection target member formed of an electrode material having good wettability of molten solder particles and another surface material having poor wettability of molten solder particles.
  • a method of selectively adhering molten solder particles that have reached the surface of the electrode to the electrode and then melting and adhering another solder particle to the molten solder particles, and an electrode material with good thermal conductivity And other surface materials with poor thermal conductivity are selected, and when heat is applied, the temperature of the electrode is raised relative to the other surface members to selectively
  • the solder particles are selectively agglomerated on the electrodes by using solder particles that have been treated so as to have a positive charge with respect to the negative charges existing on the electrode formed of metal.
  • the thickness of the solder part between the electrodes is preferably 10 ⁇ m or more, more preferably 20 ⁇ m or more, preferably 100 ⁇ m or less, more preferably 80 ⁇ m or less.
  • the solder wetted area on the surface of the electrode is preferably 50% or more, more preferably 60% or more, still more preferably 70% or more, preferably 100. % Or less.
  • the step of arranging the second connection target member and the step of forming the connection portion no pressure is applied, and the second connection is applied to the conductive paste.
  • the weight of the target member is added, or pressure is applied in at least one of the step of arranging the second connection target member and the step of forming the connection portion, and the second connection target member It is preferable that the pressure of pressurization is less than 1 MPa in both the step of disposing and the step of forming the connecting portion. By not applying a pressure of 1 MPa or more, the aggregation of solder particles is considerably promoted.
  • the pressure of pressurization may be less than 1 MPa in both the step of performing pressure and arranging the second connection target member and the step of forming the connection portion.
  • the pressurization may be performed only in the step of arranging the second connection target member, or the pressurization may be performed only in the step of forming the connection portion.
  • Pressurization may be performed in both the step of arranging the connection target member and the step of forming the connection portion.
  • the case where the pressure is less than 1 MPa includes the case where no pressure is applied.
  • the pressure of pressurization is preferably 0.9 MPa or less, more preferably 0.8 MPa or less.
  • the pressure of the pressurization is 0.8 MPa or less, the aggregation of the solder particles is further promoted more remarkably than when the pressure of the pressurization exceeds 0.8 MPa.
  • connection structure in the step of arranging the second connection target member and the step of forming the connection portion, no pressure is applied, and the second connection is applied to the conductive paste.
  • the weight of the target member is preferably added, and in the step of arranging the second connection target member and the step of forming the connection portion, the conductive paste exceeds the weight force of the second connection target member. It is preferable that no pressure is applied.
  • the uniformity of the amount of solder can be further enhanced in the plurality of solder portions.
  • the thickness of the solder portion can be increased more effectively, and a plurality of solder particles can be easily collected between the electrodes, and the plurality of solder particles can be arranged more efficiently on the electrodes (lines).
  • the conduction reliability between the electrodes can be further enhanced.
  • the electrical connection between the laterally adjacent electrodes that should not be connected can be further prevented, and the insulation reliability can be further improved.
  • connection portion if no weight is applied and the weight of the second connection target member is added to the conductive paste, the connection portion
  • the solder particles arranged in the region (space) where the electrode is not formed before the electrode is formed are more easily collected between the first electrode and the second electrode, so that the plurality of solder particles are separated from the electrode (line).
  • the present inventor has also found that the above can be arranged more efficiently.
  • a configuration in which a conductive paste is used instead of a conductive film and a configuration in which the weight of the second connection target member is added to the conductive paste without applying pressure are used in combination. This has a great meaning in order to obtain the effects of the present invention at a higher level.
  • WO2008 / 023452A1 describes that it is preferable to pressurize with a predetermined pressure at the time of bonding from the viewpoint of efficiently moving the solder powder to the electrode surface, and the pressurizing pressure further ensures the solder area.
  • the pressure is set to 0 MPa or more, preferably 1 MPa or more.
  • a predetermined pressure may be applied to the adhesive tape by its own weight.
  • WO2008 / 023452A1 it is described that the pressure applied intentionally to the adhesive tape may be 0 MPa, but there is no difference between the effect when the pressure exceeding 0 MPa is applied and when the pressure is set to 0 MPa. Not listed.
  • WO2008 / 023452A1 recognizes nothing about the importance of using a paste-like conductive paste instead of a film.
  • the conductive film in order to change or adjust the thickness of the connection portion, it is necessary to prepare a conductive film having a different thickness or to prepare a conductive film having a predetermined thickness. There is.
  • the conductive film has a problem that the melt viscosity of the conductive film cannot be sufficiently lowered at the melting temperature of the solder, and the aggregation of the solder particles is hindered.
  • FIG. 1 is a cross-sectional view schematically showing a connection structure obtained using a conductive paste according to an embodiment of the present invention.
  • connection structure 1 shown in FIG. 1 is a connection that connects a first connection target member 2, a second connection target member 3, and the first connection target member 2 and the second connection target member 3.
  • Part 4 The connection portion 4 is formed of a conductive paste including a thermosetting compound, a thermosetting agent, a plurality of solder particles, and a plurality of spacers 5.
  • the thermosetting compound and the thermosetting agent are thermosetting components.
  • the connecting portion 4 includes a solder portion 4A in which a plurality of solder particles are gathered and joined to each other, a cured portion 4B in which a thermosetting component is thermally cured, and a spacer 5.
  • the first connection object member 2 has a plurality of first electrodes 2a on the surface (upper surface).
  • the second connection target member 3 has a plurality of second electrodes 3a on the surface (lower surface).
  • the first electrode 2a and the second electrode 3a are electrically connected by the solder portion 4A. Therefore, the first connection target member 2 and the second connection target member 3 are electrically connected by the solder portion 4A.
  • no solder exists in a region (cured product portion 4B portion) different from the solder portion 4A gathered between the first electrode 2a and the second electrode 3a.
  • the spacer 5 is in contact with both the first electrode 2 a of the first connection target member 2 and the second electrode 3 a of the second connection target member 3.
  • the distance between the first connection target member 2 and the second connection target member 3 is regulated by the spacer 5, and the distance between the first electrode 2 a and the second electrode 3 a is regulated. Even if the spacer 5 is in contact with both the region where the first electrode 2a of the first connection target member 2 is not provided and the region where the second electrode 3a of the second connection target member 3 is not provided. Good.
  • connection structure 1 a plurality of solder particles gather between the first electrode 2 a and the second electrode 3 a, and after the plurality of solder particles melt, After the electrode surface wets and spreads, it solidifies to form the solder portion 4A. For this reason, the connection area of 4 A of solder parts and the 1st electrode 2a, and 4 A of solder parts, and the 2nd electrode 3a becomes large. That is, by using the solder particles, the solder portion 4A, the first electrode 2a, and the solder portion are compared with the case where the conductive outer surface is made of a metal such as nickel, gold or copper. The contact area between 4A and the second electrode 3a increases. For this reason, the conduction
  • the conductive paste may contain a flux. When the flux is used, the flux is generally deactivated gradually by heating.
  • connection structure 1 shown in FIG. 1 all of the solder portions 4A are located in the facing region between the first and second electrodes 2a and 3a.
  • the connection structure 1X of the modification shown in FIG. 3 is different from the connection structure 1 shown in FIG. 1 only in the connection portion 4X.
  • the connection portion 4X includes a solder portion 4XA, a cured product portion 4XB, and a spacer 5X.
  • most of the solder portions 4XA are located in regions where the first and second electrodes 2a and 3a are opposed to each other, and a part of the solder portion 4XA is first and second. You may protrude to the side from the area
  • the solder part 4XA protruding laterally from the region where the first and second electrodes 2a and 3a are opposed is a part of the solder part 4XA and is not a solder separated from the solder part 4XA.
  • the amount of solder away from the solder portion can be reduced, but the solder away from the solder portion may exist in the cured product portion.
  • connection structure 1 If the amount of solder particles used is reduced, the connection structure 1 can be easily obtained. If the amount of the solder particles used is increased, it becomes easy to obtain the connection structure 1X. Note that it is sufficient that the solder wets and spreads on the surface of the electrode, and the solder does not necessarily have to be gathered between the upper and lower electrodes.
  • the first electrode 2a is provided on the surface, and the first convex portion 2y is provided in a region where the first electrode 2a on the first electrode 2a side is absent.
  • the second connection target having the first connection target member 2Y and the second electrode 3a on the surface and the second protrusion 3y in the region where the second electrode 3a on the second electrode 3a side is not present.
  • the member 3Y may be used.
  • the first convex part 2y protrudes from the first electrode 2a.
  • the 2nd convex part 3y protrudes rather than the 2nd electrode 3a.
  • the distance between the first protrusion 2y and the second protrusion 3y is narrower than the distance between the first electrode 2a and the second electrode 3a.
  • connection portion 4Y includes a solder portion 4YA, a cured product portion 4YB, and a spacer 5Y.
  • the spacer 5Y is in contact with both the first protrusion 2y and the second protrusion 3y. As a result, the distance between the first electrode 2a and the second electrode 3a is regulated by the spacer 5Y.
  • the portion where the first electrode and the second electrode face each other in the stacking direction of the first electrode, the connection portion, and the second electrode is seen.
  • the solder portion in the connection portion is disposed at 90% or more.
  • the first electrode and the second electrode are opposed to each other in a direction orthogonal to the stacking direction of the first electrode, the connection portion, and the second electrode. It is preferable that 70% or more of the solder portion in the connection portion is disposed in a portion where the first electrode and the second electrode face each other when the matching portion is viewed.
  • connection structure 1 using the conductive paste according to the embodiment of the present invention will be described.
  • the first connection target member 2 having the first electrode 2a on the surface (upper surface) is prepared.
  • the conductive paste 11 including the thermosetting component 11 ⁇ / b> B, the plurality of solder particles 11 ⁇ / b> A, and the spacer 5 is disposed on the surface of the first connection target member 2.
  • the conductive paste 11 is disposed on the surface of the first connection target member 2 on which the first electrode 2a is provided.
  • the solder particles 11A are disposed both on the first electrode 2a (line) and on a region (space) where the first electrode 2a is not formed.
  • the arrangement method of the conductive paste 11 is not particularly limited, and examples thereof include application with a dispenser, screen printing, and ejection with an inkjet device.
  • the 2nd connection object member 3 which has the 2nd electrode 3a on the surface (lower surface) is prepared.
  • the 2nd connection object member 3 is arrange
  • the second connection target member 3 is disposed from the second electrode 3a side. At this time, the first electrode 2a and the second electrode 3a are opposed to each other.
  • the conductive paste 11 is heated above the melting point of the solder particles 11A and above the curing temperature of the thermosetting component 11B (third step). That is, the conductive paste 11 is heated to a temperature lower than the melting point of the solder particles 11A and the curing temperature of the thermosetting component 11B. At the time of this heating, the solder particles 11A that existed in the region where no electrode is formed gather between the first electrode 2a and the second electrode 3a (self-aggregation effect).
  • the conductive paste since the conductive paste is used instead of the conductive film, the conductive paste further has a specific composition, so that the solder particles 11A are disposed between the first electrode 2a and the second electrode 3a. To gather effectively. Also, the solder particles 11A are melted and joined together.
  • thermosetting component 11B is thermoset.
  • the connection portion 4 connecting the first connection target member 2 and the second connection target member 3 is formed with the conductive paste 11.
  • the connection part 4 is formed by the conductive paste 11
  • the solder part 4A is formed by joining a plurality of solder particles 11A
  • the cured part 4B is formed by thermosetting the thermosetting component 11B. If the solder particles 11A are sufficiently moved, the first electrode 2a and the second electrode are moved after the movement of the solder particles 11A not located between the first electrode 2a and the second electrode 3a starts. It is not necessary to keep the temperature constant until the movement of the solder particles 11A is completed.
  • connection portion 4X includes a solder portion 4XA, a cured product portion 4XB, and a spacer 5.
  • the spacers 5 are easily pushed out by the gathering of the solder particles 11A.
  • the spacer 5 can be brought into contact with both the first connection target member 2 and the second connection target member 3.
  • the spacer 5 can be brought into contact with both the first electrode 2a and the second electrode 3a.
  • pressure is applied in at least one of the second step and the third step, the action of the solder particles trying to collect between the first electrode and the second electrode is hindered. The tendency to become higher. This has been found by the inventor.
  • the electrode of the first connection target member Even when the first connection target member and the second connection target member are overlapped in a state where the alignment with the electrode of the second connection target member is shifted, the shift is corrected and the first connection target is corrected.
  • the electrode of the member can be connected to the electrode of the second connection target member (self-alignment effect). This is because the molten solder self-aggregated between the electrode of the first connection target member and the electrode of the second connection target member is the electrode of the first connection target member and the electrode of the second connection target member.
  • the area where the solder and the other components of the conductive paste are in contact with each other is minimized, the area becomes more stable in terms of energy. Because. At this time, it is desirable that the conductive paste is not cured and that the viscosity of components other than the solder particles of the conductive paste is sufficiently low at that temperature and time.
  • the spacer exists between the first connection target member and the second connection target member, the distance between the electrode of the first connection target member and the electrode of the second connection target member is sufficient. Can be secured. Thereby, the space where the solder particles aggregate can be secured, and the aggregation property of the solder particles can be improved. Furthermore, since a sufficient amount of solder can be secured between the electrode of the first connection target member and the electrode of the second connection target member, the self-alignment effect can be obtained even when the opposing electrodes are shifted and overlapped. It becomes easy to express.
  • the preferred amount of electrode displacement after the conductive connection is preferably 0 L or more (0 or more), preferably 0.9 L or less, more preferably 0.75 L or less, where L is the electrode width.
  • the preferable deviation amount X after the electric connection is preferably 0R or more (0 or more), preferably 3R or less, more preferably 2R or less when the particle diameter of the spacer is R.
  • the viscosity of the conductive paste at the melting point temperature of the solder is preferably 50 Pa ⁇ s or less, more preferably 10 Pa ⁇ s or less, still more preferably 1 Pa ⁇ s or less, preferably 0.1 Pa ⁇ s or more, more preferably 0.2 Pa. -It is more than s. If the viscosity is lower than the predetermined viscosity, the solder particles can be efficiently aggregated. If the viscosity is higher than the predetermined viscosity, the void at the connection portion is suppressed, and the protrusion of the conductive paste to other than the connection portion is suppressed. Can do.
  • connection structure 1 shown in FIG. 1 is obtained.
  • the second step and the third step may be performed continuously.
  • the laminated body of the obtained 1st connection object member 2, the electrically conductive paste 11, and the 2nd connection object member 3 is moved to a heating part, and said 3rd said You may perform a process.
  • the laminate In order to perform the heating, the laminate may be disposed on a heating member, or the laminate may be disposed in a heated space.
  • the heating temperature in the third step is not particularly limited as long as it is higher than the melting point of the solder particles and higher than the curing temperature of the thermosetting component.
  • the heating temperature is preferably 140 ° C. or higher, more preferably 160 ° C. or higher, preferably 450 ° C. or lower, more preferably 250 ° C. or lower, and still more preferably 200 ° C. or lower.
  • a heating step may be provided in order to uniformize the aggregation of the solder particles before melting.
  • the heating temperature in the heating step is preferably 60 ° C. or higher, more preferably 80 ° C. or higher, preferably 130 ° C. or lower, more preferably 120 ° C. or lower, preferably 5 seconds or longer, preferably 120 seconds or shorter. Hold.
  • the thermosetting component is reduced in viscosity by heat, and the solder particles before melting are aggregated to form a network structure. When the solder particles are melted and aggregated in the third step, they do not aggregate. Solder particles can be reduced.
  • the melting point of the solder (° C.) or more preferably the melting point of the solder (° C.) + 5 ° C. or more, preferably the melting point of the solder (° C.) + 20 ° C. or less, more preferably the melting point of the solder (° C.).
  • the temperature may be raised to the curing temperature of the thermosetting component.
  • the rate of temperature increase in the third step is preferably 50 ° C./second or less, more preferably 20 ° C./second or less, further preferably 10 ° C./second or less, with respect to the temperature increase from 30 ° C. to the melting point of the solder particles. Is 1 ° C./second or more, more preferably 5 ° C./second or more.
  • the rate of temperature rise is equal to or higher than the above lower limit, the aggregation of solder particles becomes even more uniform.
  • the rate of temperature increase is equal to or less than the above upper limit, an excessive increase in viscosity due to the progress of curing of the thermosetting component is suppressed, and aggregation of solder particles is hardly inhibited.
  • a 1st connection object member or a 2nd connection object member can be peeled from a connection part for the purpose of correction of a position, or re-production.
  • the heating temperature for performing this peeling is preferably not lower than the melting point of the solder particles, more preferably not lower than the melting point (° C.) of the solder particles + 10 ° C.
  • the heating temperature for performing this peeling may be the melting point (° C.) of the solder particles + 100 ° C. or less.
  • connection structure As the heating method in the third step, a method of heating the entire connection structure using a reflow furnace or an oven above the melting point of the solder particles and the curing temperature of the thermosetting component, or a connection structure The method of heating only the connection part of a body locally is mentioned.
  • instruments used in the method of locally heating include a hot plate, a heat gun that applies hot air, a soldering iron, and an infrared heater.
  • the metal directly under the connection is made of a metal with high thermal conductivity, and other places where heating is not preferred are made of a material with low thermal conductivity such as a fluororesin.
  • the upper surface of the hot plate is preferably formed.
  • the first and second connection target members are not particularly limited. Specifically as said 1st, 2nd connection object member, electronic components, such as a semiconductor chip, a semiconductor package, LED chip, LED package, a capacitor
  • the first and second connection target members are preferably electronic components.
  • At least one of the first connection target member and the second connection target member is a resin film, a flexible printed board, a flexible flat cable, or a rigid flexible board.
  • the second connection target member is preferably a resin film, a flexible printed board, a flexible flat cable, or a rigid flexible board. Resin films, flexible printed boards, flexible flat cables, and rigid flexible boards have the property of being highly flexible and relatively lightweight. When a conductive film is used for connection of such a connection object member, there exists a tendency for a solder particle not to gather on an electrode.
  • the electrode provided on the connection target member examples include metal electrodes such as a gold electrode, a nickel electrode, a tin electrode, an aluminum electrode, a copper electrode, a molybdenum electrode, a silver electrode, a SUS electrode, and a tungsten electrode.
  • the electrode is preferably a gold electrode, a nickel electrode, a tin electrode, a silver electrode, or a copper electrode.
  • the electrode is preferably an aluminum electrode, a copper electrode, a molybdenum electrode, a silver electrode, or a tungsten electrode.
  • the electrode formed only with aluminum may be sufficient and the electrode by which the aluminum layer was laminated
  • the material for the metal oxide layer include indium oxide doped with a trivalent metal element and zinc oxide doped with a trivalent metal element.
  • the trivalent metal element include Sn, Al, and Ga.
  • the first electrode and the second electrode are arranged in an area array or a peripheral.
  • the effect of the present invention is more effectively exhibited when the electrodes are arranged on the surface of an area array or a peripheral.
  • the area array is a structure in which electrodes are arranged in a grid pattern on the surface where the electrodes of the connection target members are arranged.
  • the peripheral is a structure in which electrodes are arranged on the outer periphery of a connection target member.
  • the solder particles only have to be aggregated along the direction perpendicular to the comb, whereas in the above structure, the surface on which the electrodes are arranged is uniform over the entire surface. Since it is necessary for the solder particles to agglomerate, the amount of solder tends to be non-uniform in the conventional method, whereas in the method of the present invention, the effects of the present invention are more effectively exhibited.
  • Polymer A Synthesis of reaction product (polymer A) of bisphenol F with 1,6-hexanediol diglycidyl ether and bisphenol F type epoxy resin: 100 parts by weight of bisphenol F (containing 4,4′-methylene bisphenol, 2,4′-methylene bisphenol and 2,2′-methylene bisphenol in a weight ratio of 2: 3: 1), 1,6-hexanediol Three parts: 130 parts by weight of glycidyl ether, 5 parts by weight of bisphenol F type epoxy resin (“EPICLON EXA-830CRP” manufactured by DIC) and 10 parts by weight of resorcinol type epoxy compound (“EX-201” manufactured by Nagase ChemteX) It put into the neck flask and it was made to melt
  • bisphenol F containing 4,4′-methylene bisphenol, 2,4′-methylene bisphenol and 2,2′-methylene bisphenol in a weight ratio of 2: 3: 1
  • the reaction product (Polymer A) contains a hydroxyl group derived from bisphenol F, 1,6-hexanediol diglycidyl ether, and an epoxy group of bisphenol F type epoxy resin. It was confirmed that it has a structural unit bonded to the main chain and has an epoxy group at both ends.
  • the weight average molecular weight of the reaction product (polymer A) obtained by GPC was 28,000, and the number average molecular weight was 8,000.
  • Polymer B both ends epoxy group rigid skeleton phenoxy resin, “YX6900BH45” manufactured by Mitsubishi Chemical Corporation, weight average molecular weight 16000
  • Thermosetting compound 1 Resorcinol type epoxy compound, “EX-201” manufactured by Nagase ChemteX Corporation
  • Thermosetting compound 2 Epoxy compound, “EXA-4850-150” manufactured by DIC, molecular weight 900, epoxy equivalent 450 g / eq
  • Thermosetting agent 1 Trimethylolpropane tris (3-mercaptopropinate), “TMMP” manufactured by SC Organic Chemical Co., Ltd.
  • Latent epoxy thermosetting agent 1 T & K TOKA's “Fujicure 7000”
  • Flux 1 Glutaric acid, manufactured by Wako Pure Chemical Industries, Ltd., melting point (activation temperature) 96 ° C.
  • solder particles having anionic polymer 1 200 g of solder particle main body, 40 g of adipic acid, and 70 g of acetone are weighed in a three-necked flask, and then dehydration condensation between the hydroxyl group on the surface of the solder particle main body and the carboxyl group of adipic acid 0.3 g of dibutyltin oxide as a catalyst was added and reacted at 60 ° C. for 4 hours. Thereafter, the solder particles were collected by filtration.
  • the collected solder particles, 50 g of adipic acid, 200 g of toluene, and 0.3 g of paratoluenesulfonic acid were weighed in a three-necked flask and reacted at 120 ° C. for 3 hours while evacuating and refluxing. . At this time, the reaction was carried out while removing water produced by dehydration condensation using a Dean-Stark extraction device.
  • solder particles were collected by filtration, washed with hexane, and dried. Thereafter, the obtained solder particles were crushed with a ball mill, and then a sieve was selected so as to obtain a predetermined CV value.
  • solder particles having the anion polymer 1 were put in 10 g of methanol and the resulting solder particles were uniformly dispersed by ultrasonic treatment to obtain a dispersion.
  • the zeta potential was measured by electrophoretic measurement using this dispersion and “Delsamax PRO” manufactured by Beckman Coulter.
  • the weight average molecular weight of the anionic polymer 1 on the surface of the solder particles was obtained by dissolving the solder using 0.1N hydrochloric acid, collecting the polymer by filtration, and determining by GPC.
  • CV value of solder particles The CV value was measured with a laser diffraction particle size distribution analyzer (“LA-920” manufactured by Horiba, Ltd.).
  • conductive particles 1 Production method of conductive particles 1: Divinylbenzene resin particles having an average particle diameter of 10 ⁇ m (“Micropearl SP-210” manufactured by Sekisui Chemical Co., Ltd.) were subjected to electroless nickel plating to form a base nickel plating layer having a thickness of 0.1 ⁇ m on the surface of the resin particles. Next, the resin particles on which the base nickel plating layer was formed were subjected to electrolytic copper plating to form a 1 ⁇ m thick copper layer. Furthermore, electrolytic plating was performed using an electrolytic plating solution containing tin and bismuth to form a solder layer having a thickness of 3 ⁇ m.
  • Conductive particles 1 were prepared.
  • Spacer 1 (average particle diameter 20 ⁇ m, CV value 5%, softening point 330 ° C., manufactured by Sekisui Chemical Co., Ltd., divinylbenzene crosslinked particles, 10% K value 4400 N / mm 2 , compression recovery rate 55%)
  • Spacer 2 (average particle diameter 30 ⁇ m, CV value 5%, softening point 330 ° C., Sekisui Chemical Co., Ltd., divinylbenzene crosslinked particles, 10% K value 4200 N / mm 2 , compression recovery rate 54%)
  • Spacer 3 (average particle diameter 50 ⁇ m, CV value 5%, softening point 330 ° C., manufactured by Sekisui Chemical Co., Ltd., divinylbenzene crosslinked particles, 10% K value 4100 N / mm 2 , compression recovery rate 54%)
  • Phenoxy resin (“YP-50S” manufactured by Nippon Steel & Sumikin Chemical Co., Ltd.)
  • Glass epoxy substrate having a copper electrode pattern (copper electrode thickness 12 ⁇ m) having an L / S of 50 ⁇ m / 50 ⁇ m and an electrode length of 3 mm on the upper surface (FR-4 substrate) (first connection target member) was prepared.
  • the flexible printed circuit board (2nd connection object member) which has a copper electrode pattern (thickness of a copper electrode 12 micrometers) of L / S 50 micrometers / 50 micrometers and electrode length 3mm on the lower surface was prepared.
  • the overlapping area of the glass epoxy substrate and the flexible printed circuit board was 1.5 cm ⁇ 3 mm, and the number of connected electrodes was 75 pairs.
  • the anisotropic conductive paste immediately after production is applied by screen printing using a metal mask so that the thickness is 100 ⁇ m on the electrode of the glass epoxy substrate, and anisotropic conductive A paste layer was formed.
  • the flexible printed circuit board was laminated on the upper surface of the anisotropic conductive paste layer so that the electrodes face each other. At this time, no pressure was applied. The weight of the flexible printed board is added to the anisotropic conductive paste layer. Then, while heating the anisotropic conductive paste layer to 190 ° C., the solder is melted and the anisotropic conductive paste layer is cured at 190 ° C. for 10 seconds to obtain a first connection structure. It was.
  • a flexible printed circuit board (second connection target member) having a L / S of 75 ⁇ m / 75 ⁇ m and an electrode length of 3 mm on the lower surface of a copper electrode pattern (copper electrode thickness 12 ⁇ m) was prepared.
  • 2nd connection structure was obtained like manufacture of the 1st connection structure except having used the above-mentioned glass epoxy board and flexible printed circuit board from which L / S differs.
  • Glass epoxy substrate having a copper electrode pattern (copper electrode thickness 12 ⁇ m) with L / S of 100 ⁇ m / 100 ⁇ m and electrode length of 3 mm on the upper surface (FR-4 substrate) (first connection target member) was prepared.
  • the flexible printed circuit board (2nd connection object member) which has a copper electrode pattern (thickness of copper electrode 12 micrometers) of L / S of 100 micrometers / 100 micrometers and electrode length 3mm on the lower surface was prepared.
  • 3rd connection structure was obtained like manufacture of the 1st connection structure except having used the above-mentioned glass epoxy board and flexible printed circuit board from which L / S differs.
  • Example 1 The components shown in Table 1 below were blended in the blending amounts shown in Table 1 below to obtain anisotropic conductive paste.
  • First, second, and third connection structures were obtained in the same manner as in Example 1 except that the obtained anisotropic conductive paste was used.
  • Example 2 The components shown in Table 1 below were blended in the blending amounts shown in Table 1 below to obtain anisotropic conductive paste.
  • First, second, and third connection structures were obtained in the same manner as in Example 1 except that the obtained anisotropic conductive paste was used and a pressure of 1 MPa was applied during heating.
  • the 1st, 2nd, 3rd connection structure was obtained like Example 1 except having used an anisotropic conductive film.
  • Viscosity The viscosity ( ⁇ 25) at 25 ° C. of the anisotropic conductive paste was measured under the conditions of 25 ° C. and 5 rpm using an E-type viscometer (manufactured by Toki Sangyo Co., Ltd.).
  • the shift amount between the electrode of the glass epoxy substrate and the electrode of the flexible printed board is set to 25 ⁇ m (for the fourth connection structure), 50 ⁇ m (for the fifth connection structure).
  • connection structure 75 ⁇ m (for the sixth connection structure), and 90 ⁇ m (for the seventh connection structure)
  • the fourth to seventh connection structures are obtained in the same manner except for superposition. It was.
  • the amount of deviation between the electrodes of the glass epoxy substrate and the electrodes of the flexible printed circuit board of the obtained fourth to seventh connection structures was measured. Twenty-five fourth to seventh connection structures were produced, and the amount of displacement between the upper and lower electrodes was measured at the electrodes located at both ends of each connection structure, and the average value of the measured values was obtained. Self-alignment was determined according to the following criteria.
  • Average deviation amount is less than 10 ⁇ m ⁇ : Average deviation amount is 10 ⁇ m or more and less than 25 ⁇ m ⁇ : Average deviation amount is 25 ⁇ m or more and less than 50 ⁇ m ⁇ : Average deviation amount is 50 ⁇ m or more
  • solder placement accuracy on electrode 1 In the obtained first, second, and third connection structures, a portion where the first electrode and the second electrode face each other in the stacking direction of the first electrode, the connection portion, and the second electrode is provided. When viewed, the ratio X of the area where the solder portion in the connection portion is arranged in the area of 100% of the portion where the first electrode and the second electrode face each other was evaluated.
  • the solder placement accuracy 1 on the electrode was determined according to the following criteria.
  • Ratio X is 70% or more ⁇ : Ratio X is 60% or more and less than 70% ⁇ : Ratio X is 50% or more and less than 60% X: Ratio X is less than 50%
  • solder placement accuracy on electrode 2 In the obtained first, second, and third connection structures, the first electrode and the second electrode are opposed to each other in a direction orthogonal to the stacking direction of the first electrode, the connection portion, and the second electrode.
  • the ratio Y of the solder part in the connecting part arranged in the part where the first electrode and the second electrode face each other in 100% of the solder part in the connecting part was evaluated. .
  • the solder placement accuracy 2 on the electrode was determined according to the following criteria.
  • Ratio Y is 99% or more ⁇ : Ratio Y is 90% or more and less than 99% ⁇ : Ratio Y is 70% or more and less than 90% X: Ratio Y is less than 70%
  • ⁇ Average value of connection resistance is 10 7 ⁇ or more ⁇ : Average value of connection resistance is 10 6 ⁇ or more, less than 10 7 ⁇ ⁇ : Average value of connection resistance is 10 5 ⁇ or more, less than 10 6 ⁇ ⁇ : Connection The average resistance is less than 10 5 ⁇
  • first electrode and the second electrode are stacked in the stacking direction of the first electrode, the connection portion, and the second electrode. Whether the center line of the first electrode and the center line of the second electrode were aligned when the portion facing the two electrodes was viewed, and the distance of the positional deviation were evaluated.
  • the positional deviation between the upper and lower electrodes was determined according to the following criteria.
  • Misalignment is less than 15 ⁇ m ⁇ : Misalignment is 15 ⁇ m or more and less than 25 ⁇ m ⁇ : Misalignment is 25 ⁇ m or more and less than 40 ⁇ m ⁇ : Misalignment is 40 ⁇ m or more

Abstract

Provided is an electroconductive paste with which it is possible to control with high precision gaps between electrodes, and with which it is further possible to efficiently dispose solder particles on the electrodes, and to increase conduction reliability between electrodes. The electroconductive paste according to the present invention is used for connecting a first member to be connected having a first electrode on the surface thereof and a second member to be connected having a second electrode on the surface thereof, and electrically connecting the first electrode and the second electrode. The electroconductive paste includes a thermosetting component, a plurality of solder particles, and a plurality of spacers having a melting point of 250°C or higher, the average particle diameter of the spacers being greater than the average particle diameter of the solder particles.

Description

導電ペースト、接続構造体及び接続構造体の製造方法Conductive paste, connection structure, and manufacturing method of connection structure
　本発明は、はんだ粒子を含む導電ペーストに関する。また、本発明は、上記導電ペーストを用いた接続構造体及び接続構造体の製造方法に関する。 The present invention relates to a conductive paste containing solder particles. The present invention also relates to a connection structure using the conductive paste and a method for manufacturing the connection structure.
　異方性導電ペースト及び異方性導電フィルム等の異方性導電材料が広く知られている。上記異方性導電材料では、バインダー樹脂中に導電性粒子が分散されている。 Anisotropic conductive materials such as anisotropic conductive paste and anisotropic conductive film are widely known. In the anisotropic conductive material, conductive particles are dispersed in a binder resin.
　上記異方性導電材料は、各種の接続構造体を得るために、例えば、フレキシブルプリント基板とガラス基板との接続（ＦＯＧ（Ｆｉｌｍ　ｏｎ　Ｇｌａｓｓ））、半導体チップとフレキシブルプリント基板との接続（ＣＯＦ（Ｃｈｉｐ　ｏｎ　Ｆｉｌｍ））、半導体チップとガラス基板との接続（ＣＯＧ（Ｃｈｉｐ　ｏｎ　Ｇｌａｓｓ））、並びにフレキシブルプリント基板とガラスエポキシ基板との接続（ＦＯＢ（Ｆｉｌｍ　ｏｎ　Ｂｏａｒｄ））等に使用されている。 In order to obtain various connection structures, for example, the anisotropic conductive material may be connected between a flexible printed circuit board and a glass substrate (FOG (Film on Glass)), or connected between a semiconductor chip and a flexible printed circuit board (COF ( (Chip on Film)), connection between a semiconductor chip and a glass substrate (COG (Chip on Glass)), connection between a flexible printed circuit board and a glass epoxy substrate (FOB (Film on Board)), and the like.
　上記異方性導電材料により、例えば、フレキシブルプリント基板の電極とガラスエポキシ基板の電極とを電気的に接続する際には、ガラスエポキシ基板上に、導電性粒子を含む異方性導電材料を配置する。次に、フレキシブルプリント基板を積層して、加熱及び加圧する。これにより、異方性導電材料を硬化させて、導電性粒子を介して電極間を電気的に接続して、接続構造体を得る。 For example, when electrically connecting the electrode of the flexible printed circuit board and the electrode of the glass epoxy substrate by the anisotropic conductive material, an anisotropic conductive material containing conductive particles is disposed on the glass epoxy substrate. To do. Next, a flexible printed circuit board is laminated, and heated and pressurized. As a result, the anisotropic conductive material is cured, and the electrodes are electrically connected via the conductive particles to obtain a connection structure.
　上記異方性導電材料の一例として、下記の特許文献１には、熱硬化性樹脂を含む樹脂層と、はんだ粉と、硬化剤とを含み、上記はんだ粉と上記硬化剤とが上記樹脂層中に存在する接着テープが開示されている。この接着テープは、フィルム状であり、ペースト状ではない。 As an example of the anisotropic conductive material, the following Patent Document 1 includes a resin layer containing a thermosetting resin, solder powder, and a curing agent, and the solder powder and the curing agent include the resin layer. An adhesive tape present therein is disclosed. This adhesive tape is in the form of a film, not a paste.
　また、特許文献１では、上記接着テープを用いた接着方法が開示されている。具体的には、第一基板、接着テープ、第二基板、接着テープ、及び第三基板を下からこの順に積層して、積層体を得る。このとき、第一基板の表面に設けられた第一電極と、第二基板の表面に設けられた第二電極とを対向させる。また、第二基板の表面に設けられた第二電極と第三基板の表面に設けられた第三電極とを対向させる。そして、積層体を所定の温度で加熱して接着する。これにより、接続構造体を得る。 Further, Patent Document 1 discloses a bonding method using the above-mentioned adhesive tape. Specifically, a first substrate, an adhesive tape, a second substrate, an adhesive tape, and a third substrate are laminated in this order from the bottom to obtain a laminate. At this time, the first electrode provided on the surface of the first substrate is opposed to the second electrode provided on the surface of the second substrate. Moreover, the 2nd electrode provided in the surface of the 2nd board | substrate and the 3rd electrode provided in the surface of the 3rd board | substrate are made to oppose. Then, the laminate is heated and bonded at a predetermined temperature. Thereby, a connection structure is obtained.
　また、下記の特許文献２には、第１電子部品の接続部の電極である第１電極と、第２電子部品の接続部の電極である第２電極とを電気的に接続させる異方性導電性の接着剤が開示されている。上記異方性導電性の接着剤は、絶縁性ポリマー樹脂と、接合粒子と、スペーサ粒子とを含む。上記接合粒子は、上記異方性導電性の接着剤に印加される超音波によって発生する熱によって溶融される。上記スペーサ粒子は、上記接合粒子より高い融点を有する。上記接合粒子としては、はんだ粒子が挙げられている。 Patent Document 2 below discloses anisotropy that electrically connects a first electrode that is an electrode of a connection portion of a first electronic component and a second electrode that is an electrode of a connection portion of a second electronic component. A conductive adhesive is disclosed. The anisotropic conductive adhesive includes an insulating polymer resin, bonding particles, and spacer particles. The joining particles are melted by heat generated by ultrasonic waves applied to the anisotropic conductive adhesive. The spacer particles have a higher melting point than the bonding particles. Examples of the bonding particles include solder particles.
ＷＯ２００８／０２３４５２Ａ１WO2008 / 023452A1 特表２０１２－５３２９７９号公報Special table 2012-532979 gazette
　特許文献１に記載の接着テープは、フィルム状であり、ペースト状ではない。このため、はんだ粉を電極（ライン）上に効率的に配置することは困難である。例えば、特許文献１に記載の接着テープでは、はんだ粉の一部が、電極が形成されていない領域（スペース）にも配置されやすい。電極が形成されていない領域に配置されたはんだ粉は、電極間の導通に寄与しない。 The adhesive tape described in Patent Document 1 is a film, not a paste. For this reason, it is difficult to efficiently arrange the solder powder on the electrodes (lines). For example, in the adhesive tape described in Patent Document 1, a part of the solder powder is easily placed in a region (space) where no electrode is formed. Solder powder disposed in a region where no electrode is formed does not contribute to conduction between the electrodes.
　また、はんだ粉を含む異方性導電ペーストであっても、はんだ粉が電極（ライン）上に効率的に配置されないことがある。さらに、はんだ粉を含む異方性導電ペーストを用いた場合には、導電接続後に、電極間の間隔にばらつきが生じやすい。また、特許文献２に記載の接着剤でも、はんだ粒子などの接合粒子が電極（ライン）上に効率的に配置されないことがある。また、特許文献２に記載のように、はんだ粒子などの接合粒子とは別に、スペーサ粒子を用いたとしても、接合粒子が電極（ライン）上に効率的に配置されないことがある。 Also, even if the anisotropic conductive paste contains solder powder, the solder powder may not be efficiently disposed on the electrodes (lines). Furthermore, when an anisotropic conductive paste containing solder powder is used, the gap between the electrodes tends to vary after the conductive connection. Further, even with the adhesive described in Patent Document 2, bonding particles such as solder particles may not be efficiently arranged on the electrodes (lines). Further, as described in Patent Document 2, even when spacer particles are used separately from bonding particles such as solder particles, the bonding particles may not be efficiently arranged on the electrodes (lines).
　本発明の目的は、電極間の間隔を高精度に制御することができ、更にはんだ粒子を電極上に効率的に配置することができ、電極間の導通信頼性を高めることができる導電ペーストを提供することである。また、本発明は、上記導電ペーストを用いた接続構造体及び接続構造体の製造方法を提供することである。 An object of the present invention is to provide a conductive paste that can control the interval between the electrodes with high accuracy, can further efficiently arrange the solder particles on the electrodes, and can improve the conduction reliability between the electrodes. Is to provide. Moreover, this invention is providing the manufacturing method of the connection structure and connection structure using the said electrically conductive paste.
　本発明の広い局面によれば、第１の電極を表面に有する第１の接続対象部材と第２の電極を表面に有する第２の接続対象部材とを接続し、前記第１の電極と前記第２の電極とを電気的に接続するために用いられる導電ペーストであって、熱硬化性成分と、複数のはんだ粒子と、融点が２５０℃以上である複数のスペーサとを含み、前記スペーサの平均粒子径は、前記はんだ粒子の平均粒子径よりも大きい、導電ペーストが提供される。 According to a wide aspect of the present invention, the first connection target member having the first electrode on the surface and the second connection target member having the second electrode on the surface are connected, and the first electrode and the A conductive paste used to electrically connect a second electrode, comprising a thermosetting component, a plurality of solder particles, and a plurality of spacers having a melting point of 250 ° C. or higher, A conductive paste having an average particle size larger than the average particle size of the solder particles is provided.
　本発明に係る導電ペーストのある特定の局面では、前記スペーサが絶縁性粒子である。 In a specific aspect of the conductive paste according to the present invention, the spacer is an insulating particle.
　本発明に係る導電ペーストのある特定の局面では、前記導電ペーストは、前記スペーサが、前記第１の接続対象部材と前記第２の接続対象部材との双方に接するように用いられる。 In a specific aspect of the conductive paste according to the present invention, the conductive paste is used so that the spacer is in contact with both the first connection target member and the second connection target member.
　本発明に係る導電ペーストのある特定の局面では、前記導電ペーストは、前記第１の電極と前記第２の電極とを電気的に接続する際に、前記はんだ粒子の融点以上かつ前記熱硬化性成分の硬化温度以上に加熱し、複数の前記はんだ粒子を凝集させ、一体化させて用いられる。 In a specific aspect of the conductive paste according to the present invention, the conductive paste has a temperature equal to or higher than the melting point of the solder particles and the thermosetting property when electrically connecting the first electrode and the second electrode. It is used by heating above the curing temperature of the components to aggregate and integrate the plurality of solder particles.
　本発明に係る導電ペーストのある特定の局面では、前記スペーサの平均粒子径の、前記はんだ粒子の平均粒子径に対する比が１．１以上、１５以下である。 In a specific aspect of the conductive paste according to the present invention, the ratio of the average particle diameter of the spacer to the average particle diameter of the solder particles is 1.1 or more and 15 or less.
　本発明に係る導電ペーストのある特定の局面では、前記スペーサの含有量が０．１重量％以上、１０重量％以下である。 In a specific aspect of the conductive paste according to the present invention, the content of the spacer is 0.1 wt% or more and 10 wt% or less.
　本発明に係る導電ペーストのある特定の局面では、前記はんだ粒子の平均粒子径が１μｍ以上、４０μｍ以下である。 In a specific aspect of the conductive paste according to the present invention, the solder particles have an average particle diameter of 1 μm or more and 40 μm or less.
　本発明に係る導電ペーストのある特定の局面では、前記はんだ粒子の含有量が１０重量％以上、８０重量％以下である。 In a specific aspect of the conductive paste according to the present invention, the content of the solder particles is 10% by weight or more and 80% by weight or less.
　本発明に係る導電ペーストのある特定の局面では、前記はんだ粒子の重量％単位での含有量の、前記スペーサの重量％単位での含有量に対する比が、２以上、１００以下である。 In a specific aspect of the conductive paste according to the present invention, the ratio of the content of the solder particles in wt% to the content of the spacer in wt% is 2 or more and 100 or less.
　本発明の広い局面によれば、少なくとも１つの第１の電極を表面に有する第１の接続対象部材と、少なくとも１つの第２の電極を表面に有する第２の接続対象部材と、前記第１の接続対象部材と、前記第２の接続対象部材とを接続している接続部とを備え、前記接続部の材料が、上述した導電ペーストであり、前記第１の電極と前記第２の電極とが、前記接続部中のはんだ部により電気的に接続されており、前記スペーサが、前記第１の接続対象部材と前記第２の接続対象部材との双方に接触している、接続構造体が提供される。 According to a wide aspect of the present invention, a first connection target member having at least one first electrode on the surface, a second connection target member having at least one second electrode on the surface, and the first The connection target member and the connection part connecting the second connection target member, and the material of the connection part is the conductive paste described above, and the first electrode and the second electrode Are electrically connected by a solder portion in the connection portion, and the spacer is in contact with both the first connection target member and the second connection target member. Is provided.
　本発明の広い局面によれば、上述した導電ペーストを用いて、少なくとも１つの第１の電極を表面に有する第１の接続対象部材の表面上に、前記導電ペーストを配置する工程と、前記導電ペーストの前記第１の接続対象部材側とは反対の表面上に、少なくとも１つの第２の電極を表面に有する第２の接続対象部材を、前記第１の電極と前記第２の電極とが対向するように配置する工程と、前記はんだ粒子の融点以上かつ前記熱硬化性成分の硬化温度以上に前記導電ペーストを加熱することで、前記第１の接続対象部材と前記第２の接続対象部材とを接続している接続部を、前記導電ペーストにより形成し、かつ、前記第１の電極と前記第２の電極とを、前記接続部中のはんだ部により電気的に接続し、前記第１の接続対象部材と前記第２の接続対象部材との双方に前記スペーサを接触させる工程とを備える、接続構造体の製造方法が提供される。 According to a wide aspect of the present invention, using the conductive paste described above, the step of disposing the conductive paste on the surface of the first connection target member having at least one first electrode on the surface; On the surface opposite to the first connection target member side of the paste, the second connection target member having at least one second electrode on the surface is formed by the first electrode and the second electrode. The first connection target member and the second connection target member are disposed so as to face each other, and by heating the conductive paste to a temperature equal to or higher than the melting point of the solder particles and equal to or higher than the curing temperature of the thermosetting component. Are formed by the conductive paste, and the first electrode and the second electrode are electrically connected by a solder portion in the connection portion, and the first electrode The connection object member and the second And a step of contacting the spacers to both the connection target member, the manufacturing method of the connecting structure is provided.
　本発明に係る接続構造体の製造方法のある特定の局面では、前記第１の電極と前記第２の電極とを電気的に接続する際に、前記はんだ粒子の融点以上かつ前記熱硬化性成分の硬化温度以上に加熱し、複数の前記はんだ粒子を凝集させ、一体化させる。 In a specific aspect of the manufacturing method of the connection structure according to the present invention, when the first electrode and the second electrode are electrically connected, the thermosetting component is equal to or higher than the melting point of the solder particles. Is heated to a temperature equal to or higher than the curing temperature, and a plurality of the solder particles are aggregated and integrated.
　本発明に係る接続構造体の製造方法のある特定の局面では、前記第２の接続対象部材を配置する工程及び前記接続部を形成する工程において、加圧を行わず、前記導電ペーストには、前記第２の接続対象部材の重量が加わる。 In a specific aspect of the method for manufacturing a connection structure according to the present invention, in the step of arranging the second connection target member and the step of forming the connection portion, no pressure is applied, and the conductive paste includes The weight of the second connection target member is added.
　前記第２の接続対象部材が、樹脂フィルム、フレキシブルプリント基板、フレキシブルフラットケーブル、又はリジッドフレキシブル基板であることが好ましい。 It is preferable that the second connection target member is a resin film, a flexible printed board, a flexible flat cable, or a rigid flexible board.
　本発明に係る導電ペーストは、熱硬化性成分と、複数のはんだ粒子と、融点が２５０℃以上である複数のスペーサとを含むので、第１の電極を表面に有する第１の接続対象部材と第２の電極を表面に有する第２の接続対象部材とを接続し、上記第１の電極と上記第２の電極とを電気的に接続した場合に、電極間の間隔を高精度に制御することができ、更にはんだ粒子を電極上に効率的に配置することができ、電極間の導通信頼性を高めることができる。 Since the conductive paste according to the present invention includes a thermosetting component, a plurality of solder particles, and a plurality of spacers having a melting point of 250 ° C. or higher, the first connection target member having the first electrode on the surface thereof, When the second connection target member having the second electrode on the surface is connected and the first electrode and the second electrode are electrically connected, the interval between the electrodes is controlled with high accuracy. In addition, the solder particles can be efficiently disposed on the electrodes, and the conduction reliability between the electrodes can be improved.
図１は、本発明の一実施形態に係る導電ペーストを用いて得られる接続構造体を模式的に示す断面図である。FIG. 1 is a cross-sectional view schematically showing a connection structure obtained using a conductive paste according to an embodiment of the present invention. 図２（ａ）～（ｃ）は、本発明の一実施形態に係る導電ペーストを用いて、接続構造体を製造する方法の一例の各工程を説明するための断面図である。2A to 2C are cross-sectional views for explaining each step of an example of a method for manufacturing a connection structure using the conductive paste according to the embodiment of the present invention. 図３は、接続構造体の変形例を示す断面図である。FIG. 3 is a cross-sectional view showing a modification of the connection structure. 図４は、接続構造体の変形例を示す断面図である。FIG. 4 is a cross-sectional view showing a modification of the connection structure.
　以下、本発明の詳細を説明する。 Hereinafter, the details of the present invention will be described.
　（導電ペースト）
　本発明に係る導電ペーストは、第１の電極を表面に有する第１の接続対象部材と第２の電極を表面に有する第２の接続対象部材とを接続し、上記第１の電極と上記第２の電極とを電気的に接続するために用いられる。本発明に係る導電ペーストは、熱硬化性成分と、複数のはんだ粒子と、融点が２５０℃以上である複数のスペーサとを含む。 (Conductive paste)
The conductive paste according to the present invention connects the first connection target member having the first electrode on the surface and the second connection target member having the second electrode on the surface, and the first electrode and the first electrode Used to electrically connect the two electrodes. The conductive paste according to the present invention includes a thermosetting component, a plurality of solder particles, and a plurality of spacers having a melting point of 250 ° C. or higher.
　本発明に係る導電ペーストでは、上記スペーサの平均粒子径は、上記はんだ粒子の平均粒子径よりも大きい。 In the conductive paste according to the present invention, the average particle size of the spacer is larger than the average particle size of the solder particles.
　本発明に係る導電ペーストでは、上記の構成が採用されているので、電極間を電気的に接続した場合に、電極間の間隔を高精度に制御することができる。さらに、はんだ粒子が電極間に集まるときにスペーサによって上下の電極の間隔が十分に確保されるので、複数のはんだ粒子が上下の対向した電極間に集まりやすく、複数のはんだ粒子を電極（ライン）上に効率的に配置することができる。また、複数のはんだ粒子の一部が、電極が形成されていない領域（スペース）に配置され難く、電極が形成されていない領域に配置されるはんだ粒子の量をかなり少なくすることができる。従って、電極間の導通信頼性を高めることができる。しかも、接続されてはならない横方向に隣接する電極間の電気的な接続を防ぐことができ、絶縁信頼性を高めることができる。本発明では、スペーサを配合することで、はんだ粒子を電極上に効率的に配置することができる。さらに、本発明では、スペーサを単に配合しているだけでなく、スペーサとはんだ粒子との平均粒子径を特定の範囲に設定しているため、はんだ粒子を電極上に効率的に配置することができる。特定の平均粒子径を有するスペーサの使用は、接続されるべき上下の電極間におけるはんだの量及び配置精度の向上に大きく寄与する。 Since the conductive paste according to the present invention employs the above-described configuration, the distance between the electrodes can be controlled with high accuracy when the electrodes are electrically connected. Furthermore, since the space between the upper and lower electrodes is sufficiently secured by the spacer when the solder particles gather between the electrodes, the plurality of solder particles are likely to gather between the upper and lower opposing electrodes, and the plurality of solder particles are separated into electrodes (lines). Can be efficiently placed on top. Moreover, it is difficult for some of the plurality of solder particles to be disposed in a region (space) where no electrode is formed, and the amount of solder particles disposed in a region where no electrode is formed can be considerably reduced. Therefore, the conduction reliability between the electrodes can be improved. In addition, it is possible to prevent electrical connection between laterally adjacent electrodes that should not be connected, and to improve insulation reliability. In this invention, a solder particle can be efficiently arrange | positioned on an electrode by mix | blending a spacer. Furthermore, in the present invention, since the average particle diameter of the spacer and the solder particles is set within a specific range, not only the spacer is simply blended, the solder particles can be efficiently arranged on the electrode. it can. The use of a spacer having a specific average particle size greatly contributes to improvement in the amount of solder and the placement accuracy between the upper and lower electrodes to be connected.
　上記スペーサの平均粒子径が上記はんだ粒子の平均粒子径よりも大きいことで、はんだ粒子が電極上に移動する際に、第１の接続対象部材と第２の接続対象部材との間にはんだ粒子が移動できる間隔が確保され、はんだ粒子の移動が促進される。結果として、上下の電極間に配置されるはんだ量が多くなるので、電極間の導通信頼性が高くなる。 When the average particle diameter of the spacer is larger than the average particle diameter of the solder particles, the solder particles move between the first connection target member and the second connection target member when the solder particles move on the electrode. The space | interval which can move is ensured and the movement of a solder particle is accelerated | stimulated. As a result, since the amount of solder disposed between the upper and lower electrodes increases, the conduction reliability between the electrodes increases.
　また、本発明では、スペーサの使用によって、スペーサが上下の電極の間隔を規制するだけでなく、スペーサがはんだ粒子の凝集性を高めることに寄与することが見出された。 Also, in the present invention, it has been found that the use of a spacer not only regulates the distance between the upper and lower electrodes, but also contributes to increasing the cohesiveness of the solder particles.
　さらに、本発明では、電極間の位置ずれを防ぐことができる。本発明では、導電ペーストを塗布した第１の接続対象部材に、第２の接続対象部材を重ね合わせた際に、第１の接続対象部材の電極と第２の接続対象部材の電極のアライメントがずれた状態で、第１の接続対象部材と第２の接続対象部材とが重ね合わされた場合でも、そのずれを補正して、第１の接続対象部材の電極と第２の接続対象部材の電極とを接続させることができる（セルフアライメント効果）。 Furthermore, in the present invention, it is possible to prevent displacement between the electrodes. In the present invention, when the second connection target member is superimposed on the first connection target member to which the conductive paste is applied, the alignment of the electrode of the first connection target member and the electrode of the second connection target member is performed. Even when the first connection target member and the second connection target member are overlapped in a shifted state, the shift is corrected and the electrodes of the first connection target member and the second connection target member are corrected. Can be connected (self-alignment effect).
　なお、上記はんだ粒子ではなく、はんだにより形成されていない基材粒子と基材粒子の表面上に配置されたはんだ層とを備える導電性粒子を用いた場合には、電極上に導電性粒子が集まりにくくなり、導電性粒子同士のはんだ接合性が低いために、電極上に移動した導電性粒子が電極外に移動しやすくなる。このため、電極間の位置ずれの抑制効果も低くなる。 In addition, when using conductive particles including base particles not formed of solder and a solder layer disposed on the surface of the base particles, the conductive particles are not formed on the electrodes. Since it becomes difficult to gather and the solder bonding property between the conductive particles is low, the conductive particles that have moved onto the electrode are likely to move out of the electrode. For this reason, the effect of suppressing the displacement between the electrodes is also reduced.
　はんだ粒子を電極上により一層効率的に配置するために、上記導電ペーストの２５℃での粘度（η２５）は好ましくは１０Ｐａ・ｓ以上、より好ましくは５０Ｐａ・ｓ以上、更に好ましくは１００Ｐａ・ｓ以上、好ましくは８００Ｐａ・ｓ以下、より好ましくは６００Ｐａ・ｓ以下、更に好ましくは５００Ｐａ・ｓ以下である。 In order to more efficiently arrange the solder particles on the electrode, the viscosity (η25) at 25 ° C. of the conductive paste is preferably 10 Pa · s or more, more preferably 50 Pa · s or more, and further preferably 100 Pa · s or more. , Preferably 800 Pa · s or less, more preferably 600 Pa · s or less, and even more preferably 500 Pa · s or less.
　上記粘度（η２５）は、配合成分の種類及び配合量に適宜調整可能である。また、フィラーの使用により、粘度を比較的高くすることができる。 The viscosity (η25) can be adjusted as appropriate to the type and amount of the compounding ingredients. Further, the use of a filler can make the viscosity relatively high.
　上記粘度（η２５）は、例えば、Ｅ型粘度計（東機産業社製）等を用いて、２５℃及び５ｒｐｍの条件で測定可能である。 The viscosity (η25) can be measured using, for example, an E-type viscometer (manufactured by Toki Sangyo Co., Ltd.) and the like at 25 ° C. and 5 rpm.
　本発明に係る導電ペーストは、後述する本発明に係る接続構造体及び接続構造体の製造方法に好適に用いることができる。 The conductive paste according to the present invention can be suitably used for a connection structure according to the present invention described later and a method for manufacturing the connection structure.
　導通信頼性をより一層高める観点からは、上記導電ペーストは、上記第１の電極と上記第２の電極とを電気的に接続する際に、上記はんだ粒子の融点以上かつ上記熱硬化性成分の硬化温度以上に加熱し、複数の上記はんだ粒子を凝集させ、一体化させて用いられることが好ましい。複数のはんだ粒子の一体化により、より大面積のはんだ部が形成される。１つのはんだ部において、導電ペースト中の２以上のはんだ粒子が一体化していることが好ましく、導電ペースト中の３以上のはんだ粒子が一体化していることがより好ましく、導電ペースト中の５以上のはんだ粒子が一体化していることが更に好ましい。 From the viewpoint of further improving the conduction reliability, the conductive paste has a temperature equal to or higher than the melting point of the solder particles and the thermosetting component when electrically connecting the first electrode and the second electrode. It is preferable that the plurality of solder particles are aggregated and integrated by heating to a temperature higher than the curing temperature. By integrating the plurality of solder particles, a solder area with a larger area is formed. In one solder part, two or more solder particles in the conductive paste are preferably integrated, more preferably three or more solder particles in the conductive paste are integrated, and five or more in the conductive paste More preferably, the solder particles are integrated.
　上記導電ペーストは、電極の電気的な接続に好適に用いられる。上記導電ペーストは、回路接続材料であることが好ましい。 The conductive paste is preferably used for electrical connection of electrodes. The conductive paste is preferably a circuit connection material.
　以下、上記導電ペーストに含まれる各成分を説明する。 Hereinafter, each component contained in the conductive paste will be described.
　（はんだ粒子）
　上記はんだ粒子は、はんだを導電性の外表面に有する。上記はんだ粒子は、中心部分及び導電性の外表面とのいずれもがはんだにより形成されている。上記はんだ粒子は、上記はんだ粒子の中心部分及び導電性の外表面とのいずれもがはんだである粒子である。 (Solder particles)
The solder particles have solder on a conductive outer surface. As for the said solder particle, both a center part and an electroconductive outer surface are formed with the solder. The solder particles are particles in which both the central portion of the solder particles and the conductive outer surface are solder.
　電極上にはんだ粒子を効率的に集める観点からは、上記はんだ粒子の表面のゼータ電位がプラスであることが好ましい。但し、本発明では、上記はんだ粒子の表面のゼータ電位がプラスでなくてもよい。 From the viewpoint of efficiently collecting solder particles on the electrode, it is preferable that the zeta potential on the surface of the solder particles is positive. However, in the present invention, the zeta potential of the surface of the solder particle may not be positive.
　ゼータ電位は以下のようにして測定される。 Zeta potential is measured as follows.
　ゼータ電位の測定方法：
　はんだ粒子０．０５ｇを、メタノール１０ｇに入れ、超音波処理等をすることで、均一に分散させて、分散液を得る。この分散液を用いて、かつＢｅｃｋｍａｎ　Ｃｏｕｌｔｅｒ社製「Ｄｅｌｓａｍａｘ　ＰＲＯ」を用いて、電気泳動測定法にて、２３℃でゼータ電位を測定することができる。 Zeta potential measurement method:
0.05 g of solder particles are put in 10 g of methanol and subjected to ultrasonic treatment or the like to uniformly disperse to obtain a dispersion. Using this dispersion and using “Delsamax PRO” manufactured by Beckman Coulter, the zeta potential can be measured at 23 ° C. by electrophoretic measurement.
　はんだ粒子のゼータ電位は好ましくは０ｍＶ以上、より好ましくは０ｍＶを超え、好ましくは１０ｍＶ以下、より好ましくは５ｍＶ以下、より一層好ましくは１ｍＶ以下、更に好ましくは０．７ｍＶ以下、特に好ましくは０．５ｍＶ以下である。ゼータ電位が上記上限以下であると、使用前の導電ペースト中にて、はんだ粒子が凝集しにくくなる。ゼータ電位が０ｍＶ以上であると、実装時に電極上にはんだ粒子が効率的に凝集する。 The zeta potential of the solder particles is preferably 0 mV or more, more preferably more than 0 mV, preferably 10 mV or less, more preferably 5 mV or less, even more preferably 1 mV or less, still more preferably 0.7 mV or less, particularly preferably 0.5 mV. It is as follows. When the zeta potential is less than or equal to the above upper limit, the solder particles hardly aggregate in the conductive paste before use. When the zeta potential is 0 mV or more, the solder particles efficiently aggregate on the electrode during mounting.
　表面のゼータ電位をプラスにすることが容易であることから、上記はんだ粒子は、はんだ粒子本体と、上記はんだ粒子本体の表面上に配置されたアニオンポリマーとを有することが好ましい。上記はんだ粒子は、はんだ粒子本体をアニオンポリマー又はアニオンポリマーとなる化合物で表面処理することにより得られることが好ましい。上記はんだ粒子は、アニオンポリマー又はアニオンポリマーとなる化合物による表面処理物であることが好ましい。上記アニオンポリマー及び上記アニオンポリマーとなる化合物はそれぞれ、１種のみが用いられてもよく、２種以上が併用されてもよい。 Since it is easy to make the zeta potential of the surface positive, the solder particles preferably have a solder particle body and an anionic polymer disposed on the surface of the solder particle body. The solder particles are preferably obtained by surface-treating the solder particle body with an anionic polymer or a compound that becomes an anionic polymer. The solder particles are preferably a surface treated product of an anion polymer or a compound that becomes an anion polymer. As for the said anion polymer and the compound used as the said anion polymer, only 1 type may respectively be used and 2 or more types may be used together.
　はんだ粒子本体をアニオンポリマーで表面処理する方法としては、アニオンポリマーとして、例えば（メタ）アクリル酸を共重合した（メタ）アクリルポリマー、ジカルボン酸とジオールとから合成されかつ両末端にカルボキシル基を有するポリエステルポリマー、ジカルボン酸の分子間脱水縮合反応により得られかつ両末端にカルボキシル基を有するポリマー、ジカルボン酸とジアミンから合成されかつ両末端にカルボキシル基を有するポリエステルポリマー、並びにカルボキシル基を有する変性ポバール（日本合成化学社製「ゴーセネックスＴ」）等を用いて、アニオンポリマーのカルボキシル基と、はんだ粒子本体の表面の水酸基とを反応させる方法が挙げられる。 As a method of surface-treating the solder particle body with an anionic polymer, as an anionic polymer, for example, a (meth) acrylic polymer copolymerized with (meth) acrylic acid, synthesized from a dicarboxylic acid and a diol and having carboxyl groups at both ends Polyester polymer, polymer obtained by intermolecular dehydration condensation reaction of dicarboxylic acid and having carboxyl groups at both ends, polyester polymer synthesized from dicarboxylic acid and diamine and having carboxyl groups at both ends, and modified poval having carboxyl groups ( A method of reacting a carboxyl group of an anionic polymer with a hydroxyl group on the surface of a solder particle body using “GOHSEX T” manufactured by Nippon Synthetic Chemical Co., Ltd., etc.
　上記アニオンポリマーのアニオン部分としては、上記カルボキシル基が挙げられ、それ以外には、トシル基（ｐ－Ｈ３ＣＣ６Ｈ４Ｓ（＝Ｏ）２－）、スルホン酸イオン基（－ＳＯ３ －）、及びリン酸イオン基（－ＰＯ４ －）等が挙げられる。 Examples of the anion portion of the anionic polymer include the carboxyl group, and other than that, a tosyl group (p—H 3 CC 6 H 4 S (═O) 2 —), a sulfonate ion group (—SO 3 —) ), And phosphate ion groups (—PO 4 − ) and the like.
　また、他の方法としては、はんだ粒子本体の表面の水酸基と反応する官能基を有し、さらに、付加、縮合反応により重合可能な官能基を有する化合物を用いて、この化合物をはんだ粒子本体の表面上にてポリマー化する方法が挙げられる。はんだ粒子本体の表面の水酸基と反応する官能基としては、カルボキシル基、及びイソシアネート基等が挙げられ、付加、縮合反応により重合する官能基としては、水酸基、カルボキシル基、アミノ基、及び（メタ）アクリロイル基が挙げられる。 As another method, a compound having a functional group that reacts with a hydroxyl group on the surface of the solder particle body and having a functional group that can be polymerized by addition or condensation reaction is used. The method of polymerizing on the surface is mentioned. Examples of the functional group that reacts with the hydroxyl group on the surface of the solder particle body include a carboxyl group and an isocyanate group. Examples of the functional group that polymerizes by addition and condensation reactions include a hydroxyl group, a carboxyl group, an amino group, and (meth). An acryloyl group is mentioned.
　上記アニオンポリマーの重量平均分子量は好ましくは２０００以上、より好ましくは３０００以上、好ましくは１００００以下、より好ましくは８０００以下である。 The weight average molecular weight of the anionic polymer is preferably 2000 or more, more preferably 3000 or more, preferably 10,000 or less, more preferably 8000 or less.
　上記重量平均分子量が上記下限以上及び上記上限以下であると、はんだ粒子本体の表面上にアニオンポリマーを配置することが容易であり、はんだ粒子の表面のゼータ電位をプラスにすることが容易であり、電極上にはんだ粒子をより一層効率的に配置することができる。 When the weight average molecular weight is not less than the above lower limit and not more than the above upper limit, it is easy to dispose an anionic polymer on the surface of the solder particle body, and it is easy to make the zeta potential on the surface of the solder particle positive. The solder particles can be arranged on the electrodes even more efficiently.
　上記重量平均分子量は、ゲルパーミエーションクロマトグラフィー（ＧＰＣ）により測定されたポリスチレン換算での重量平均分子量を示す。 The weight average molecular weight indicates a weight average molecular weight in terms of polystyrene measured by gel permeation chromatography (GPC).
　はんだ粒子本体をアニオンポリマーとなる化合物で表面処理することにより得られたポリマーの重量平均分子量は、はんだ粒子中のはんだを溶解し、ポリマーの分解を起こさない希塩酸等により、はんだ粒子を除去した後、残存しているポリマーの重量平均分子量を測定することで求めることができる。 The weight average molecular weight of the polymer obtained by surface-treating the solder particle body with a compound that becomes an anionic polymer is obtained by dissolving the solder in the solder particles and removing the solder particles with dilute hydrochloric acid or the like that does not cause decomposition of the polymer. It can be determined by measuring the weight average molecular weight of the remaining polymer.
　上記はんだは、融点が４５０℃以下である金属（低融点金属）であることが好ましい。上記はんだ粒子は、融点が４５０℃以下である金属粒子（低融点金属粒子）であることが好ましい。上記低融点金属粒子は、低融点金属を含む粒子である。該低融点金属とは、融点が４５０℃以下の金属を示す。低融点金属の融点は好ましくは３００℃以下、より好ましくは１６０℃以下である。また、上記はんだ粒子は錫を含む。上記はんだ粒子に含まれる金属１００重量％中、錫の含有量は好ましくは３０重量％以上、より好ましくは４０重量％以上、更に好ましくは７０重量％以上、特に好ましくは９０重量％以上である。上記はんだ粒子における錫の含有量が上記下限以上であると、はんだ部と電極との接続信頼性がより一層高くなる。 The solder is preferably a metal (low melting point metal) having a melting point of 450 ° C. or lower. The solder particles are preferably metal particles (low melting point metal particles) having a melting point of 450 ° C. or lower. The low melting point metal particles are particles containing a low melting point metal. The low melting point metal is a metal having a melting point of 450 ° C. or lower. The melting point of the low melting point metal is preferably 300 ° C. or lower, more preferably 160 ° C. or lower. The solder particles include tin. In 100% by weight of the metal contained in the solder particles, the content of tin is preferably 30% by weight or more, more preferably 40% by weight or more, still more preferably 70% by weight or more, and particularly preferably 90% by weight or more. When the content of tin in the solder particles is equal to or higher than the lower limit, the connection reliability between the solder portion and the electrode is further enhanced.
　なお、上記錫の含有量は、高周波誘導結合プラズマ発光分光分析装置（堀場製作所社製「ＩＣＰ－ＡＥＳ」）、又は蛍光Ｘ線分析装置（島津製作所社製「ＥＤＸ－８００ＨＳ」）等を用いて測定可能である。 The tin content is determined using a high-frequency inductively coupled plasma emission spectrometer (“ICP-AES” manufactured by Horiba, Ltd.) or a fluorescent X-ray analyzer (“EDX-800HS” manufactured by Shimadzu). It can be measured.
　上記はんだ粒子を用いることで、はんだが溶融して電極に接合し、はんだ部が電極間を導通させる。例えば、はんだ部と電極とが点接触ではなく面接触しやすいため、接続抵抗が低くなる。また、はんだ粒子の使用により、はんだ部と電極との接合強度が高くなる結果、はんだ部と電極との剥離がより一層生じ難くなり、導通信頼性及び接続信頼性が効果的に高くなる。 By using the above solder particles, the solder is melted and joined to the electrodes, and the solder portion conducts between the electrodes. For example, since the solder portion and the electrode are not in point contact but in surface contact, the connection resistance is lowered. In addition, the use of solder particles increases the bonding strength between the solder portion and the electrode. As a result, peeling between the solder portion and the electrode is further less likely to occur, and the conduction reliability and the connection reliability are effectively increased.
　上記はんだ粒子を構成する金属（低融点金属）は特に限定されない。該低融点金属は、錫、又は錫を含む合金であることが好ましい。該合金は、錫－銀合金、錫－銅合金、錫－銀－銅合金、錫－ビスマス合金、錫－亜鉛合金、錫－インジウム合金等が挙げられる。電極に対する濡れ性に優れることから、上記低融点金属は、錫、錫－銀合金、錫－銀－銅合金、錫－ビスマス合金、錫－インジウム合金であることが好ましい。錫－ビスマス合金、錫－インジウム合金であることがより好ましい。 The metal (low melting point metal) constituting the solder particles is not particularly limited. The low melting point metal is preferably tin or an alloy containing tin. Examples of the alloy include a tin-silver alloy, a tin-copper alloy, a tin-silver-copper alloy, a tin-bismuth alloy, a tin-zinc alloy, and a tin-indium alloy. The low melting point metal is preferably tin, tin-silver alloy, tin-silver-copper alloy, tin-bismuth alloy, or tin-indium alloy because of its excellent wettability to the electrode. More preferred are a tin-bismuth alloy and a tin-indium alloy.
　上記はんだ粒子は、ＪＩＳ　Ｚ３００１：溶接用語に基づき、液相線が４５０℃以下である溶加材であることが好ましい。上記はんだ粒子の組成としては、例えば亜鉛、金、銀、鉛、銅、錫、ビスマス、インジウムなどを含む金属組成が挙げられる。低融点で鉛フリーである錫－インジウム系（１１７℃共晶）、又は錫－ビスマス系（１３９℃共晶）が好ましい。すなわち、上記はんだ粒子は、鉛を含まないことが好ましく、錫とインジウムとを含むか、又は錫とビスマスとを含むことが好ましい。 The solder particles are preferably a filler material having a liquidus line of 450 ° C. or lower based on JIS Z3001: Welding terms. Examples of the composition of the solder particles include metal compositions containing zinc, gold, silver, lead, copper, tin, bismuth, indium and the like. A tin-indium system (117 ° C. eutectic) or a tin-bismuth system (139 ° C. eutectic), which has a low melting point and is free of lead, is preferred. That is, the solder particles preferably do not contain lead, and preferably contain tin and indium, or contain tin and bismuth.
　上記はんだ部と電極との接合強度をより一層高めるために、上記はんだ粒子は、ニッケル、銅、アンチモン、アルミニウム、亜鉛、鉄、金、チタン、リン、ゲルマニウム、テルル、コバルト、ビスマス、マンガン、クロム、モリブデン、パラジウム等の金属を含んでいてもよい。また、はんだ部と電極との接合強度をさらに一層高める観点からは、上記はんだ粒子は、ニッケル、銅、アンチモン、アルミニウム又は亜鉛を含むことが好ましい。はんだ部と電極との接合強度をより一層高める観点からは、接合強度を高めるためのこれらの金属の含有量は、はんだ粒子１００重量％中、好ましくは０．０００１重量％以上、好ましくは１重量％以下である。 In order to further increase the bonding strength between the solder part and the electrode, the solder particles include nickel, copper, antimony, aluminum, zinc, iron, gold, titanium, phosphorus, germanium, tellurium, cobalt, bismuth, manganese, chromium. Further, it may contain a metal such as molybdenum and palladium. Moreover, from the viewpoint of further increasing the bonding strength between the solder portion and the electrode, the solder particles preferably contain nickel, copper, antimony, aluminum, or zinc. From the viewpoint of further increasing the bonding strength between the solder part and the electrode, the content of these metals for increasing the bonding strength is preferably 0.0001% by weight or more, preferably 1% by weight in 100% by weight of the solder particles. % Or less.
　上記はんだ粒子の平均粒子径は、好ましくは０．５μｍ以上、より好ましくは１μｍ以上、更に好ましくは３μｍ以上、特に好ましくは５μｍ以上、好ましくは１００μｍ以下、より好ましくは８０μｍ未満、より一層好ましくは７５μｍ以下、より一層好ましくは６０μｍ以下、より一層好ましくは４０μｍ以下、より一層好ましくは３０μｍ以下、更に好ましくは２０μｍ以下、特に好ましくは１５μｍ以下、最も好ましくは１０μｍ以下である。上記はんだ粒子の平均粒子径が上記下限以上及び上記上限以下であると、はんだ粒子を電極上により一層効率的に配置することができる。上記はんだ粒子の平均粒子径は、３μｍ以上、３０μｍ以下であることが特に好ましい。 The average particle size of the solder particles is preferably 0.5 μm or more, more preferably 1 μm or more, still more preferably 3 μm or more, particularly preferably 5 μm or more, preferably 100 μm or less, more preferably less than 80 μm, still more preferably 75 μm. Hereinafter, it is more preferably 60 μm or less, even more preferably 40 μm or less, still more preferably 30 μm or less, still more preferably 20 μm or less, particularly preferably 15 μm or less, and most preferably 10 μm or less. When the average particle diameter of the solder particles is not less than the above lower limit and not more than the above upper limit, the solder particles can be more efficiently arranged on the electrode. The average particle diameter of the solder particles is particularly preferably 3 μm or more and 30 μm or less.
　上記はんだ粒子の「平均粒子径」は、数平均粒子径を示す。はんだ粒子の平均粒子径は、例えば、任意のはんだ粒子５０個を電子顕微鏡又は光学顕微鏡にて観察し、平均値を算出することや、レーザー回折式粒度分布測定を行うことにより求められる。 “The average particle diameter” of the solder particles indicates the number average particle diameter. The average particle diameter of the solder particles is obtained, for example, by observing 50 arbitrary solder particles with an electron microscope or an optical microscope, calculating an average value, or performing laser diffraction particle size distribution measurement.
　上記はんだ粒子の粒子径の変動係数は、好ましくは５％以上、より好ましくは１０％以上、好ましくは４０％以下、より好ましくは３０％以下である。上記粒子径の変動係数が上記下限以上及び上記上限以下であると、電極上にはんだ粒子をより一層効率的に配置することができる。但し、上記はんだ粒子の粒子径の変動係数は、５％未満であってもよい。 The coefficient of variation of the particle diameter of the solder particles is preferably 5% or more, more preferably 10% or more, preferably 40% or less, more preferably 30% or less. When the variation coefficient of the particle diameter is not less than the above lower limit and not more than the above upper limit, the solder particles can be more efficiently arranged on the electrode. However, the coefficient of variation of the particle diameter of the solder particles may be less than 5%.
　上記変動係数（ＣＶ値）は下記式で表される。 The above coefficient of variation (CV value) is expressed by the following equation.
　ＣＶ値（％）＝（ρ／Ｄｎ）×１００
　ρ：はんだ粒子の粒子径の標準偏差
　Ｄｎ：はんだ粒子の粒子径の平均値 CV value (%) = (ρ / Dn) × 100
ρ: Standard deviation of particle diameter of solder particles Dn: Average value of particle diameter of solder particles
　上記はんだ粒子の形状は特に限定されない。上記はんだ粒子の形状は、球状であってもよく、扁平状などの球形状以外の形状であってもよい。 The shape of the solder particles is not particularly limited. The solder particles may have a spherical shape or a shape other than a spherical shape such as a flat shape.
　上記導電ペースト１００重量％中、上記はんだ粒子の含有量は好ましくは１重量％以上、より好ましくは２重量％以上、更に好ましくは１０重量％以上、特に好ましくは２０重量％以上、最も好ましくは３０重量％以上、好ましくは８０重量％以下、より好ましくは６０重量％以下、更に好ましくは５０重量％以下である。上記はんだ粒子の含有量が上記下限以上及び上記上限以下であると、電極上にはんだ粒子をより一層効率的に配置することができ、電極間にはんだ粒子を多く配置することが容易であり、導通信頼性がより一層高くなる。導通信頼性をより一層高める観点からは、上記はんだ粒子の含有量は多い方が好ましい。 The content of the solder particles in 100% by weight of the conductive paste is preferably 1% by weight or more, more preferably 2% by weight or more, still more preferably 10% by weight or more, particularly preferably 20% by weight or more, and most preferably 30%. % By weight or more, preferably 80% by weight or less, more preferably 60% by weight or less, and still more preferably 50% by weight or less. When the content of the solder particles is not less than the above lower limit and not more than the above upper limit, it is possible to more efficiently arrange the solder particles on the electrodes, and it is easy to arrange many solder particles between the electrodes, The conduction reliability is further increased. From the viewpoint of further improving the conduction reliability, it is preferable that the content of the solder particles is large.
　電極が形成されている部分のライン（Ｌ）が５０μｍ以上、１５０μｍ未満である場合に、導通信頼性をより一層高める観点からは、上記導電ペースト１００重量％中、上記はんだ粒子の含有量は好ましくは２０重量％以上、より好ましくは３０重量％以上、好ましくは５５重量％以下、より好ましくは４５重量％以下である。 When the line (L) where the electrode is formed is 50 μm or more and less than 150 μm, the content of the solder particles is preferably 100% by weight of the conductive paste from the viewpoint of further improving the conduction reliability. Is 20% by weight or more, more preferably 30% by weight or more, preferably 55% by weight or less, more preferably 45% by weight or less.
　電極が形成されていない部分のスペース（Ｓ）が５０μｍ以上、１５０μｍ未満である場合に、導通信頼性をより一層高める観点からは、上記導電ペースト１００重量％中、上記はんだ粒子の含有量は好ましくは３０重量％以上、より好ましくは４０重量％以上、好ましくは７０重量％以下、より好ましくは６０重量％以下である。 From the viewpoint of further improving the conduction reliability when the space (S) where the electrode is not formed is 50 μm or more and less than 150 μm, the content of the solder particles is preferably 100% by weight of the conductive paste. Is 30% by weight or more, more preferably 40% by weight or more, preferably 70% by weight or less, more preferably 60% by weight or less.
　電極が形成されている部分のライン（Ｌ）が１５０μｍ以上、１０００μｍ未満である場合に、導通信頼性をより一層高める観点からは、上記導電ペースト１００重量％中、上記はんだ粒子の含有量は好ましくは３０重量％以上、より好ましくは４０重量％以上、好ましくは７０重量％以下、より好ましくは６０重量％以下である。 In the case where the line (L) where the electrode is formed is 150 μm or more and less than 1000 μm, the content of the solder particles is preferably 100% by weight of the conductive paste from the viewpoint of further improving the conduction reliability. Is 30% by weight or more, more preferably 40% by weight or more, preferably 70% by weight or less, more preferably 60% by weight or less.
　電極が形成されていない部分のスペース（Ｓ）が１５０μｍ以上、１０００μｍ未満である場合に、導通信頼性をより一層高める観点からは、上記導電ペースト１００重量％中、上記はんだ粒子の含有量は好ましくは３０重量％以上、より好ましくは４０重量％以上、好ましくは７０重量％以下、より好ましくは６０重量％以下である。 In the case where the space (S) where the electrode is not formed is 150 μm or more and less than 1000 μm, from the viewpoint of further improving the conduction reliability, the content of the solder particles is preferably 100% by weight of the conductive paste. Is 30% by weight or more, more preferably 40% by weight or more, preferably 70% by weight or less, more preferably 60% by weight or less.
　（スペーサ）
　上記スペーサは、上記第１の接続対象部材と上記第２の接続対象部材との双方に接するように好適に用いられる。従って、本発明に係る導電ペーストは、上記スペーサが上記第１の接続対象部材と上記第２の接続対象部材との双方に接するように好適に用いられる。上記スペーサは、上記第１の接続対象部材の上記第１の電極（上記第１の電極が設けられている領域）と上記第２の接続対象部材の上記第２の電極（上記第２の電極が設けられている領域）との双方に接するように好適に用いられる。上記スペーサは、上記第１の接続対象部材の上記第１の電極が設けられていない領域と上記第２の接続対象部材の上記第２の電極が設けられていない領域との双方に接するようにも好適に用いられる。導電接続時にはんだが電極間に集まろうとする作用によって、スペーサは電極が設けられていない領域に移動しやすい。一方で、上記スペーサは電極間に配置されることがある。 (Spacer)
The spacer is preferably used so as to contact both the first connection target member and the second connection target member. Therefore, the conductive paste according to the present invention is suitably used so that the spacer contacts both the first connection target member and the second connection target member. The spacer includes the first electrode (region where the first electrode is provided) of the first connection target member and the second electrode (second electrode of the second connection target member). It is preferably used so as to be in contact with both the region and the region provided with. The spacer is in contact with both a region where the first electrode of the first connection target member is not provided and a region where the second electrode of the second connection target member is not provided. Are also preferably used. The spacer tends to move to a region where no electrode is provided due to the action of the solder trying to gather between the electrodes during the conductive connection. On the other hand, the spacer may be disposed between the electrodes.
　上記スペーサの融点は２５０℃以上である。第１の電極と第２の電極との電気的な接続時に、上記スペーサが溶融しないように、融点が高めに設定されている。上記スペーサの融点の上限は特に限定されない。上記スペーサの融点は４００℃以下であってもよい。 The melting point of the spacer is 250 ° C. or higher. The melting point is set high so that the spacer does not melt when the first electrode and the second electrode are electrically connected. The upper limit of the melting point of the spacer is not particularly limited. The melting point of the spacer may be 400 ° C. or less.
　スペーサの溶融をより一層防ぐ観点からは、上記スペーサの融点は好ましくは３００℃以上、より好ましくは３５０℃以上である。 From the viewpoint of further preventing melting of the spacer, the melting point of the spacer is preferably 300 ° C. or higher, more preferably 350 ° C. or higher.
　上記スペーサは樹脂粒子であってもよい。樹脂粒子の材料としては、例えば、ポリオレフィン樹脂、アクリル樹脂、フェノール樹脂、メラミン樹脂、ベンゾグアナミン樹脂、尿素樹脂、エポキシ樹脂、不飽和ポリエステル樹脂、飽和ポリエステル樹脂、ポリエチレンテレフタレート、ポリスルホン、ポリフェニレンオキサイド、ポリアセタール、ポリイミド、ポリアミドイミド、ポリエーテルエーテルケトン、ポリエーテルスルホン、ジビニルベンゼン重合体、及びビニルベンゼン－スチレン共重合体やジビニルベンゼン－（メタ）アクリル酸エステル共重合体等のジビニルベンゼン系共重合体等が挙げられる。上記樹脂粒子の硬度を好適な範囲に容易に制御できるので、上記樹脂粒子の材料は、エチレン性不飽和基を有する重合性単量体を１種又は２種以上重合させた重合体であることが好ましい。特に、ジビニルベンゼン重合体、ポリイミド又はポリアミドイミドが好ましい。 The spacer may be resin particles. Examples of the resin particle material include polyolefin resin, acrylic resin, phenol resin, melamine resin, benzoguanamine resin, urea resin, epoxy resin, unsaturated polyester resin, saturated polyester resin, polyethylene terephthalate, polysulfone, polyphenylene oxide, polyacetal, polyimide , Polyamideimide, polyetheretherketone, polyethersulfone, divinylbenzene polymer, and divinylbenzene copolymers such as vinylbenzene-styrene copolymer and divinylbenzene- (meth) acrylate copolymer It is done. Since the hardness of the resin particles can be easily controlled within a suitable range, the material of the resin particles is a polymer obtained by polymerizing one or more polymerizable monomers having an ethylenically unsaturated group. Is preferred. In particular, divinylbenzene polymer, polyimide or polyamideimide is preferable.
　また、上記スペーサの材料としては、樹脂の他に、シリカ、ガラス、石英、シリコーン、金属、及び金属酸化物等が挙げられる。上記スペーサの材料は金属でなくてもよい。上記スペーサの材料は、樹脂であることが好ましく、ジビニルベンゼン系共重合体であることがより好ましい。上記ジビニルベンゼン系共重合体は、例えば、共重合成分としてジビニルベンゼンを含む。 In addition to the resin, examples of the material for the spacer include silica, glass, quartz, silicone, metal, and metal oxide. The material of the spacer need not be a metal. The material of the spacer is preferably a resin, and more preferably a divinylbenzene copolymer. The divinylbenzene copolymer includes, for example, divinylbenzene as a copolymerization component.
　横方向に隣接する電極間にスペーサが配置されることがあるので、絶縁信頼性をより一層高める観点からは、上記スペーサは、絶縁性粒子であることが好ましい。 Since a spacer may be disposed between the electrodes adjacent in the lateral direction, the spacer is preferably an insulating particle from the viewpoint of further improving the insulation reliability.
　上記スペーサの平均粒子径は、好ましくは１０μｍ以上、より好ましくは２０μｍ以上、更に好ましくは２５μｍ以上、好ましくは１００μｍ以下、より好ましくは７５μｍ以下、より一層好ましくは５０μｍ以下である。上記スペーサの平均粒子径が上記下限以上及び上記上限以下であると、電極間の間隔をより一層高精度に制御でき、はんだ粒子を電極上により一層効率的に配置することができる。 The average particle size of the spacer is preferably 10 μm or more, more preferably 20 μm or more, still more preferably 25 μm or more, preferably 100 μm or less, more preferably 75 μm or less, and even more preferably 50 μm or less. When the average particle diameter of the spacer is not less than the above lower limit and not more than the above upper limit, the distance between the electrodes can be controlled with higher accuracy, and the solder particles can be arranged more efficiently on the electrodes.
　上記スペーサの「平均粒子径」は、数平均粒子径を示す。スペーサの平均粒子径は、例えば、任意のスペーサ５０個を電子顕微鏡又は光学顕微鏡にて観察し、平均値を算出することや、レーザー回折式粒度分布測定を行うことにより求められる。 “The average particle diameter” of the spacer indicates the number average particle diameter. The average particle diameter of the spacers can be obtained, for example, by observing 50 arbitrary spacers with an electron microscope or an optical microscope, calculating an average value, or performing laser diffraction particle size distribution measurement.
　電極間を高精度に制御し、はんだを電極上に効率的に配置する観点から、上記スペーサの平均粒子径は、上記はんだ粒子の平均粒子径よりも大きい。 The average particle diameter of the spacer is larger than the average particle diameter of the solder particles from the viewpoint of controlling between the electrodes with high accuracy and efficiently arranging the solder on the electrodes.
　電極間をより一層高精度に制御し、はんだを電極上により一層効率的に配置する観点からは、上記スペーサの平均粒子径の、上記はんだ粒子の平均粒子径に対する比（スペーサの平均粒子径／はんだ粒子の平均粒子径）は好ましくは１．１以上、より好ましくは１．５以上、更に好ましくは２以上、好ましくは１５以下、より好ましくは１０以下、更に好ましくは８以下である。電極間を更に一層高精度に制御し、はんだを電極上に更に一層効率的に配置する観点からは、上記スペーサの平均粒子径の、上記はんだ粒子の平均粒子径に対する比（スペーサの平均粒子径／はんだ粒子の平均粒子径）は好ましくは１．０以上、より好ましくは１．５以上、好ましくは１５以下、より好ましくは１０以下である。 From the viewpoint of controlling the distance between the electrodes with higher accuracy and more efficiently arranging the solder on the electrodes, the ratio of the average particle diameter of the spacer to the average particle diameter of the solder particles (average particle diameter of the spacer / The average particle diameter of the solder particles is preferably 1.1 or more, more preferably 1.5 or more, still more preferably 2 or more, preferably 15 or less, more preferably 10 or less, still more preferably 8 or less. From the viewpoint of controlling the distance between the electrodes with higher accuracy and more efficiently arranging the solder on the electrodes, the ratio of the average particle diameter of the spacer to the average particle diameter of the solder particles (average particle diameter of the spacer) / (Average particle diameter of solder particles) is preferably 1.0 or more, more preferably 1.5 or more, preferably 15 or less, more preferably 10 or less.
　上記スペーサの粒子径の変動係数は、好ましくは３％以上、より好ましくは５％以上、好ましくは３０％以下、より好ましくは２０％以下である。上記粒子径の変動係数が上記下限以上及び上記上限以下であると、電極間の間隔をより一層高精度に制御できる。 The coefficient of variation of the particle diameter of the spacer is preferably 3% or more, more preferably 5% or more, preferably 30% or less, more preferably 20% or less. When the variation coefficient of the particle diameter is not less than the lower limit and not more than the upper limit, the distance between the electrodes can be controlled with higher accuracy.
　上記変動係数（ＣＶ値）は下記式で表される。 The above coefficient of variation (CV value) is expressed by the following equation.
　ＣＶ値（％）＝（ρ／Ｄｎ）×１００
　ρ：スペーサの粒子径の標準偏差
　Ｄｎ：スペーサの粒子径の平均値 CV value (%) = (ρ / Dn) × 100
ρ: Standard deviation of the particle diameter of the spacer Dn: Average value of the particle diameter of the spacer
　電極間をより一層高精度に制御し、はんだを電極上により一層効率的に配置する観点からは、上記はんだ粒子の重量％単位での含有量（導電ペースト１００重量％中）の、上記スペーサの重量％単位での含有量（導電ペースト１００重量％中）に対する比（はんだ粒子の含有量（重量％）／スペーサの含有量（重量％））は、好ましくは２以上、より好ましくは５以上、更に好ましくは１０以上、好ましくは１００以下、より好ましくは８０以下、更に好ましくは７０である。 From the viewpoint of controlling the distance between the electrodes with higher accuracy and more efficiently arranging the solder on the electrodes, the content of the solder particles in units of% by weight (in 100% by weight of the conductive paste) of the spacer The ratio (content of solder particles (wt%) / content of spacer (wt%)) with respect to the content in wt% (in 100 wt% of conductive paste) is preferably 2 or more, more preferably 5 or more, More preferably, it is 10 or more, preferably 100 or less, more preferably 80 or less, and still more preferably 70.
　電極間をより一層高精度に制御し、はんだを電極上により一層効率的に配置する観点からは、上記スペーサの１０％Ｋ値（１０％圧縮した時の圧縮弾性率）は、好ましくは２０００Ｎ／ｍｍ２以上より好ましくは３５００Ｎ／ｍｍ２以上、好ましくは８０００Ｎ／ｍｍ２以下、より好ましくは６０００Ｎ／ｍｍ２以下である。また、上記スペーサの１０％Ｋ値が上記下限以上及び上記上限以下であると、スペーサが第１の電極と第２の電極との双方に接した後に、スペーサの過度の移動を防ぐことができ、はんだ粒子の凝集が促進され、第１の電極と第２の電極との位置ずれも防ぐことができ、導通信頼性を高めることができる。 From the viewpoint of controlling the distance between the electrodes with higher accuracy and arranging the solder more efficiently on the electrodes, the 10% K value (compression elastic modulus when compressed to 10%) of the spacer is preferably 2000 N / mm 2 or more, more preferably 3500 N / mm 2 or more, preferably 8000 N / mm 2 or less, and more preferably not more than 6000 N / mm 2. In addition, if the 10% K value of the spacer is not less than the above lower limit and not more than the above upper limit, excessive movement of the spacer can be prevented after the spacer contacts both the first electrode and the second electrode. Aggregation of the solder particles is promoted, displacement between the first electrode and the second electrode can be prevented, and conduction reliability can be improved.
　上記スペーサの１０％Ｋ値は、以下のようにして測定できる。 The 10% K value of the spacer can be measured as follows.
　微小圧縮試験機を用いて、円柱（直径５０μｍ、ダイヤモンド製）の平滑圧子端面で、２５℃、最大試験荷重９０ｍＮを３０秒かけて負荷する条件下でスペーサを圧縮する。このときの荷重値（Ｎ）及び圧縮変位（ｍｍ）を測定する。得られた測定値から、圧縮弾性率を下記式により求めることができる。上記微小圧縮試験機として、例えば、フィッシャー社製「フィッシャースコープＨ－１００」等が用いられる。 Using a micro-compression tester, the spacer is compressed with a smooth indenter end face of a cylinder (diameter 50 μm, made of diamond) under conditions where a maximum test load of 90 mN is applied for 30 seconds. The load value (N) and compression displacement (mm) at this time are measured. From the measured value obtained, the compression modulus can be obtained by the following formula. As the micro compression tester, for example, “Fischer Scope H-100” manufactured by Fischer is used.
　Ｋ値（Ｎ／ｍｍ２）＝（３／２１／２）・Ｆ・Ｓ－３／２・Ｒ－１／２
　Ｆ：スペーサが１０％圧縮変形したときの荷重値（Ｎ）
　Ｓ：スペーサが１０％圧縮変形したときの圧縮変位（ｍｍ）
　Ｒ：スペーサの半径（ｍｍ） K value (N / mm 2 ) = (3/2 1/2 ) · F · S −3 / 2 · R −1/2
F: Load value when the spacer is 10% compressively deformed (N)
S: Compression displacement (mm) when the spacer is 10% compressively deformed
R: Spacer radius (mm)
　電極間をより一層高精度に制御し、はんだを電極上により一層効率的に配置する観点からは、上記スペーサの圧縮回復率は、好ましくは３０％以上、より好ましくは４０％以上、好ましくは８０％以下、より好ましくは７０％以下である。また、上記スペーサの圧縮回復率が上記下限以上及び上記上限以下であると、スペーサが第１の電極と第２の電極との双方に接した後に、スペーサの過度の移動を防ぐことができ、はんだ粒子の凝集が促進され、第１の電極と第２の電極との位置ずれも防ぐことができ、導通信頼性を高めることができる。 From the viewpoint of controlling the distance between the electrodes with higher accuracy and more efficiently arranging the solder on the electrodes, the compression recovery rate of the spacer is preferably 30% or more, more preferably 40% or more, preferably 80 % Or less, more preferably 70% or less. Moreover, after the spacer is in contact with both the first electrode and the second electrode, the spacer can be prevented from excessively moving after the compression recovery rate of the spacer is not less than the lower limit and not more than the upper limit. Aggregation of the solder particles is promoted, misalignment between the first electrode and the second electrode can be prevented, and conduction reliability can be improved.
　上記圧縮回復率は、以下のようにして測定できる。 The compression recovery rate can be measured as follows.
　試料台上にスペーサを散布する。散布されたスペーサ１個について、微小圧縮試験機を用いて、円柱（直径１００μｍ、ダイヤモンド製）の平滑圧子端面で、２５℃で、スペーサの中心方向に、スペーサが４０％圧縮変形するまで負荷（反転荷重値）を与える。その後、原点用荷重値（０．４０ｍＮ）まで除荷を行う。この間の荷重－圧縮変位を測定し、下記式から圧縮回復率を求めることができる。なお、負荷速度は０．３３ｍＮ／秒とする。上記微小圧縮試験機として、例えば、フィッシャー社製「フィッシャースコープＨ－１００」等が用いられる。 ¡Spray the spacer on the sample table. Using a small compression tester, load one dispersed spacer on a smooth indenter end face of a cylinder (diameter 100 μm, made of diamond) at 25 ° C. until the spacer is 40% compressed and deformed in the center direction of the spacer ( Reverse load value). Thereafter, unloading is performed up to the origin load value (0.40 mN). The load-compression displacement during this period is measured, and the compression recovery rate can be obtained from the following equation. The load speed is 0.33 mN / sec. As the micro compression tester, for example, “Fischer Scope H-100” manufactured by Fischer is used.
　圧縮回復率（％）＝［（Ｌ１－Ｌ２）／Ｌ１］×１００
　Ｌ１：負荷を与えるときの原点用荷重値から反転荷重値に至るまでの圧縮変位
　Ｌ２：負荷を解放するときの反転荷重値から原点用荷重値に至るまでの除荷変位 Compression recovery rate (%) = [(L1-L2) / L1] × 100
L1: Compressive displacement from the origin load value to the reverse load value when applying a load L2: Unloading displacement from the reverse load value to the origin load value when releasing the load
　上記導電ペースト１００重量％中、上記スペーサの含有量は好ましくは０．１重量％以上、より好ましくは０．５重量％以上、更に好ましくは１重量％以上、好ましくは１０重量％以下、より好ましくは５重量％以下、更に好ましくは４重量％以下、特に好ましくは３重量％以下である。上記スペーサの含有量が上記下限以上及び上記上限以下であると、電極間の間隔をより一層高精度に制御でき、電極上にはんだ粒子をより一層効率的に配置することができ、電極間にはんだ粒子を多く配置することが容易であり、導通信頼性がより一層高くなる。 In 100% by weight of the conductive paste, the content of the spacer is preferably 0.1% by weight or more, more preferably 0.5% by weight or more, still more preferably 1% by weight or more, preferably 10% by weight or less, more preferably. Is 5% by weight or less, more preferably 4% by weight or less, and particularly preferably 3% by weight or less. When the content of the spacer is not less than the above lower limit and not more than the above upper limit, the distance between the electrodes can be controlled with higher accuracy, and the solder particles can be arranged more efficiently on the electrodes. It is easy to arrange many solder particles, and the conduction reliability is further enhanced.
　（熱硬化性化合物：熱硬化性成分）
　上記熱硬化性化合物は、加熱により硬化可能な化合物である。上記熱硬化性化合物としては、オキセタン化合物、エポキシ化合物、エピスルフィド化合物、（メタ）アクリル化合物、フェノール化合物、アミノ化合物、不飽和ポリエステル化合物、ポリウレタン化合物、シリコーン化合物及びポリイミド化合物等が挙げられる。導電ペーストの硬化性及び粘度をより一層良好にし、接続信頼性をより一層高める観点から、エポキシ化合物が好ましい。 (Thermosetting compound: thermosetting component)
The thermosetting compound is a compound that can be cured by heating. Examples of the thermosetting compound include oxetane compounds, epoxy compounds, episulfide compounds, (meth) acrylic compounds, phenolic compounds, amino compounds, unsaturated polyester compounds, polyurethane compounds, silicone compounds, and polyimide compounds. From the viewpoint of further improving the curability and viscosity of the conductive paste and further improving the connection reliability, an epoxy compound is preferable.
　上記導電ペースト１００重量％中、上記熱硬化性化合物の含有量は、好ましくは２０重量％以上、より好ましくは４０重量％以上、更に好ましくは５０重量％以上、好ましくは９９重量％以下、より好ましくは９８重量％以下、更に好ましくは９０重量％以下、特に好ましくは８０重量％以下である。耐衝撃性をより一層高める観点からは、上記熱硬化性成分の含有量は多い方が好ましい。 In 100% by weight of the conductive paste, the content of the thermosetting compound is preferably 20% by weight or more, more preferably 40% by weight or more, still more preferably 50% by weight or more, and preferably 99% by weight or less. Is 98% by weight or less, more preferably 90% by weight or less, and particularly preferably 80% by weight or less. From the viewpoint of further improving the impact resistance, it is preferable that the content of the thermosetting component is large.
　（熱硬化剤：熱硬化性成分）
　上記熱硬化剤は、上記熱硬化性化合物を熱硬化させる。上記熱硬化剤としては、イミダゾール硬化剤、アミン硬化剤、フェノール硬化剤、ポリチオール硬化剤などのチオール硬化剤、酸無水物、熱カチオン開始剤（熱カチオン硬化剤）及び熱ラジカル発生剤等が挙げられる。上記熱硬化剤は、１種のみが用いられてもよく、２種以上が併用されてもよい。 (Thermosetting agent: thermosetting component)
The thermosetting agent thermosets the thermosetting compound. Examples of the thermosetting agent include imidazole curing agents, amine curing agents, phenol curing agents, polythiol curing agents and other thiol curing agents, acid anhydrides, thermal cation initiators (thermal cation curing agents), and thermal radical generators. It is done. As for the said thermosetting agent, only 1 type may be used and 2 or more types may be used together.
　導電ペーストを低温でより一層速やかに硬化可能であるので、イミダゾール硬化剤、チオール硬化剤又はアミン硬化剤が好ましい。また、加熱により硬化可能な硬化性化合物と上記熱硬化剤とを混合したときに保存安定性が高くなるので、潜在性の硬化剤が好ましい。潜在性の硬化剤は、潜在性イミダゾール硬化剤、潜在性チオール硬化剤又は潜在性アミン硬化剤であることが好ましい。なお、上記熱硬化剤は、ポリウレタン樹脂又はポリエステル樹脂等の高分子物質で被覆されていてもよい。 An imidazole curing agent, a thiol curing agent, or an amine curing agent is preferable because the conductive paste can be cured more rapidly at a low temperature. Moreover, since a storage stability becomes high when the curable compound curable by heating and the thermosetting agent are mixed, a latent curing agent is preferable. The latent curing agent is preferably a latent imidazole curing agent, a latent thiol curing agent, or a latent amine curing agent. In addition, the said thermosetting agent may be coat | covered with polymeric substances, such as a polyurethane resin or a polyester resin.
　上記イミダゾール硬化剤としては、特に限定されず、２－メチルイミダゾール、２－エチル－４－メチルイミダゾール、１－シアノエチル－２－フェニルイミダゾール、１－シアノエチル－２－フェニルイミダゾリウムトリメリテート、２，４－ジアミノ－６－［２’－メチルイミダゾリル－（１’）］－エチル－ｓ－トリアジン及び２，４－ジアミノ－６－［２’－メチルイミダゾリル－（１’）］－エチル－ｓ－トリアジンイソシアヌル酸付加物等が挙げられる。 The imidazole curing agent is not particularly limited, and 2-methylimidazole, 2-ethyl-4-methylimidazole, 1-cyanoethyl-2-phenylimidazole, 1-cyanoethyl-2-phenylimidazolium trimellitate, 2, 4-Diamino-6- [2'-methylimidazolyl- (1 ')]-ethyl-s-triazine and 2,4-diamino-6- [2'-methylimidazolyl- (1')]-ethyl-s- Examples include triazine isocyanuric acid adducts.
　上記チオール硬化剤としては、特に限定されず、トリメチロールプロパントリス－３－メルカプトプロピオネート、ペンタエリスリトールテトラキス－３－メルカプトプロピオネート及びジペンタエリスリトールヘキサ－３－メルカプトプロピオネート等が挙げられる。 The thiol curing agent is not particularly limited, and examples thereof include trimethylolpropane tris-3-mercaptopropionate, pentaerythritol tetrakis-3-mercaptopropionate, and dipentaerythritol hexa-3-mercaptopropionate. .
　上記アミン硬化剤としては、特に限定されず、ヘキサメチレンジアミン、オクタメチレンジアミン、デカメチレンジアミン、３，９－ビス（３－アミノプロピル）－２，４，８，１０－テトラスピロ［５．５］ウンデカン、ビス（４－アミノシクロヘキシル）メタン、メタフェニレンジアミン及びジアミノジフェニルスルホン等が挙げられる。 The amine curing agent is not particularly limited, and hexamethylenediamine, octamethylenediamine, decamethylenediamine, 3,9-bis (3-aminopropyl) -2,4,8,10-tetraspiro [5.5]. Examples include undecane, bis (4-aminocyclohexyl) methane, metaphenylenediamine, and diaminodiphenylsulfone.
　上記熱カチオン開始剤としては、ヨードニウム系カチオン硬化剤、オキソニウム系カチオン硬化剤及びスルホニウム系カチオン硬化剤等が挙げられる。上記ヨードニウム系カチオン硬化剤としては、ビス（４－ｔｅｒｔ－ブチルフェニル）ヨードニウムヘキサフルオロホスファート等が挙げられる。上記オキソニウム系カチオン硬化剤としては、トリメチルオキソニウムテトラフルオロボラート等が挙げられる。上記スルホニウム系カチオン硬化剤としては、トリ－ｐ－トリルスルホニウムヘキサフルオロホスファート等が挙げられる。 Examples of the thermal cation initiator include iodonium cation curing agents, oxonium cation curing agents, and sulfonium cation curing agents. Examples of the iodonium-based cationic curing agent include bis (4-tert-butylphenyl) iodonium hexafluorophosphate. Examples of the oxonium-based cationic curing agent include trimethyloxonium tetrafluoroborate. Examples of the sulfonium-based cationic curing agent include tri-p-tolylsulfonium hexafluorophosphate.
　上記熱ラジカル発生剤としては、特に限定されず、アゾ化合物及び有機過酸化物等が挙げられる。上記アゾ化合物としては、アゾビスイゾブチロニトリル（ＡＩＢＮ）等が挙げられる。上記有機過酸化物としては、ジ－ｔｅｒｔ－ブチルペルオキシド及びメチルエチルケトンペルオキシド等が挙げられる。 The thermal radical generator is not particularly limited, and examples thereof include azo compounds and organic peroxides. Examples of the azo compound include azobisisobutyronitrile (AIBN). Examples of the organic peroxide include di-tert-butyl peroxide and methyl ethyl ketone peroxide.
　上記熱硬化剤の反応開始温度は、好ましくは５０℃以上、より好ましくは７０℃以上、更に好ましくは８０℃以上、好ましくは２５０℃以下、より好ましくは２００℃以下、更に好ましくは１５０℃以下、特に好ましくは１４０℃以下である。上記熱硬化剤の反応開始温度が上記下限以上及び上記上限以下であると、はんだ粒子が電極上により一層効率的に配置される。上記熱硬化剤の反応開始温度は８０℃以上、１４０℃以下であることが特に好ましい。 The reaction initiation temperature of the thermosetting agent is preferably 50 ° C or higher, more preferably 70 ° C or higher, still more preferably 80 ° C or higher, preferably 250 ° C or lower, more preferably 200 ° C or lower, still more preferably 150 ° C or lower, Especially preferably, it is 140 degrees C or less. When the reaction start temperature of the thermosetting agent is not less than the above lower limit and not more than the above upper limit, the solder particles are more efficiently arranged on the electrode. The reaction initiation temperature of the thermosetting agent is particularly preferably 80 ° C. or higher and 140 ° C. or lower.
　はんだを電極上により一層効率的に配置する観点からは、上記熱硬化剤の反応開始温度は、上記はんだ粒子におけるはんだの融点よりも、高いことが好ましく、５℃以上高いことがより好ましく、１０℃以上高いことが更に好ましい。 From the viewpoint of more efficiently arranging the solder on the electrode, the reaction initiation temperature of the thermosetting agent is preferably higher than the melting point of the solder in the solder particles, more preferably 5 ° C. or more, more preferably 10 It is more preferable that the temperature is higher than ° C.
　上記熱硬化剤の反応開始温度は、ＤＳＣでの発熱ピークの立ち上がり開始の温度を意味する。 The reaction start temperature of the thermosetting agent means the temperature at which the exothermic peak of DSC starts to rise.
　上記熱硬化剤の含有量は特に限定されない。上記熱硬化性化合物１００重量部に対して、上記熱硬化剤の含有量は、好ましくは０．０１重量部以上、より好ましくは１重量部以上、好ましくは２００重量部以下、より好ましくは１００重量部以下、更に好ましくは７５重量部以下である。熱硬化剤の含有量が上記下限以上であると、導電ペーストを充分に硬化させることが容易である。熱硬化剤の含有量が上記上限以下であると、硬化後に硬化に関与しなかった余剰の熱硬化剤が残存し難くなり、かつ硬化物の耐熱性がより一層高くなる。 The content of the thermosetting agent is not particularly limited. The content of the thermosetting agent is preferably 0.01 parts by weight or more, more preferably 1 part by weight or more, preferably 200 parts by weight or less, more preferably 100 parts by weight with respect to 100 parts by weight of the thermosetting compound. Part or less, more preferably 75 parts by weight or less. When the content of the thermosetting agent is at least the above lower limit, it is easy to sufficiently cure the conductive paste. When the content of the thermosetting agent is not more than the above upper limit, it is difficult for an excess thermosetting agent that did not participate in curing after curing to remain, and the heat resistance of the cured product is further enhanced.
　（フラックス）
　上記導電ペーストは、フラックスを含むことが好ましい。フラックスの使用により、はんだを電極上により一層効果的に配置することができる。該フラックスは特に限定されない。フラックスとして、はんだ接合等に一般的に用いられているフラックスを使用できる。上記フラックスとしては、例えば、塩化亜鉛、塩化亜鉛と無機ハロゲン化物との混合物、塩化亜鉛と無機酸との混合物、溶融塩、リン酸、リン酸の誘導体、有機ハロゲン化物、ヒドラジン、有機酸及び松脂等が挙げられる。上記フラックスは１種のみが用いられてもよく、２種以上が併用されてもよい。 (flux)
The conductive paste preferably contains a flux. By using flux, the solder can be more effectively placed on the electrode. The flux is not particularly limited. As the flux, a flux generally used for soldering or the like can be used. Examples of the flux include zinc chloride, a mixture of zinc chloride and an inorganic halide, a mixture of zinc chloride and an inorganic acid, a molten salt, phosphoric acid, a derivative of phosphoric acid, an organic halide, hydrazine, an organic acid, and pine resin. Etc. As for the said flux, only 1 type may be used and 2 or more types may be used together.
　上記溶融塩としては、塩化アンモニウム等が挙げられる。上記有機酸としては、乳酸、クエン酸、ステアリン酸、グルタミン酸及びグルタル酸等が挙げられる。上記松脂としては、活性化松脂及び非活性化松脂等が挙げられる。上記フラックスは、カルボキシル基を２個以上有する有機酸、松脂であることが好ましい。上記フラックスは、カルボキシル基を２個以上有する有機酸であってもよく、松脂であってもよい。カルボキシル基を２個以上有する有機酸、松脂の使用により、電極間の導通信頼性がより一層高くなる。 Examples of the molten salt include ammonium chloride. Examples of the organic acid include lactic acid, citric acid, stearic acid, glutamic acid, and glutaric acid. Examples of the pine resin include activated pine resin and non-activated pine resin. The flux is preferably an organic acid having two or more carboxyl groups, pine resin. The flux may be an organic acid having two or more carboxyl groups, or pine resin. By using an organic acid having two or more carboxyl groups, pine resin, the conduction reliability between the electrodes is further enhanced.
　上記松脂はアビエチン酸を主成分とするロジン類である。フラックスは、ロジン類であることが好ましく、アビエチン酸であることがより好ましい。この好ましいフラックスの使用により、電極間の導通信頼性がより一層高くなる。 The above rosins are rosins whose main component is abietic acid. The flux is preferably rosins, and more preferably abietic acid. By using this preferable flux, the conduction reliability between the electrodes is further enhanced.
　上記フラックスの活性温度（融点）は、好ましくは５０℃以上、より好ましくは７０℃以上、更に好ましくは８０℃以上、好ましくは２００℃以下、より好ましくは１９０℃以下、より一層好ましくは１６０℃以下、更に好ましくは１５０℃以下、更に一層好ましくは１４０℃以下である。上記フラックスの活性温度が上記下限以上及び上記上限以下であると、フラックス効果がより一層効果的に発揮され、はんだ粒子が電極上により一層効率的に配置される。上記フラックスの活性温度は８０℃以上、１９０℃以下であることが好ましい。上記フラックスの活性温度は８０℃以上、１４０℃以下であることが特に好ましい。 The active temperature (melting point) of the flux is preferably 50 ° C. or higher, more preferably 70 ° C. or higher, further preferably 80 ° C. or higher, preferably 200 ° C. or lower, more preferably 190 ° C. or lower, even more preferably 160 ° C. or lower. More preferably, it is 150 ° C. or less, and still more preferably 140 ° C. or less. When the activation temperature of the flux is not less than the above lower limit and not more than the above upper limit, the flux effect is more effectively exhibited, and the solder particles are more efficiently arranged on the electrode. The activation temperature of the flux is preferably 80 ° C. or higher and 190 ° C. or lower. The active temperature of the flux is particularly preferably 80 ° C. or higher and 140 ° C. or lower.
　融点が８０℃以上、１９０℃以下である上記フラックスとしては、コハク酸（融点１８６℃）、グルタル酸（融点９６℃）、アジピン酸（融点１５２℃）、ピメリン酸（融点１０４℃）、スベリン酸（融点１４２℃）等のジカルボン酸、安息香酸（融点１２２℃）、リンゴ酸（融点１３０℃）等が挙げられる。 Examples of the flux having a melting point of 80 ° C. or higher and 190 ° C. or lower include succinic acid (melting point 186 ° C.), glutaric acid (melting point 96 ° C.), adipic acid (melting point 152 ° C.), pimelic acid (melting point 104 ° C.), suberic acid Examples thereof include dicarboxylic acids such as (melting point 142 ° C.), benzoic acid (melting point 122 ° C.), and malic acid (melting point 130 ° C.).
　また、上記フラックスの沸点は２００℃以下であることが好ましい。 The boiling point of the flux is preferably 200 ° C. or lower.
　はんだを電極上により一層効率的に配置する観点からは、上記フラックスの融点は、上記はんだ粒子におけるはんだの融点よりも、高いことが好ましく、５℃以上高いことがより好ましく、１０℃以上高いことが更に好ましい。 From the viewpoint of more efficiently arranging the solder on the electrode, the melting point of the flux is preferably higher than the melting point of the solder in the solder particles, preferably 5 ° C or higher, more preferably 10 ° C or higher. Is more preferable.
　はんだを電極上により一層効率的に配置する観点からは、上記フラックスの融点は、上記熱硬化剤の反応開始温度よりも、高いことが好ましく、５℃以上高いことがより好ましく、１０℃以上高いことが更に好ましい。 From the viewpoint of more efficiently arranging the solder on the electrode, the melting point of the flux is preferably higher than the reaction start temperature of the thermosetting agent, more preferably 5 ° C or higher, more preferably 10 ° C or higher. More preferably.
　フラックスの融点が、はんだの融点より高いことにより、電極部分にはんだ粒子を効率的に凝集させることができる。これは、接合時に熱を付与した場合、接続対象部材上に形成された電極と、電極周辺の接続対象部材の部分とを比較すると、電極部分の熱伝導率が電極周辺の接続対象部材部分の熱伝導率よりも高いことにより、電極部分の昇温が速いことに起因する。はんだ粒子の融点を超えた段階では、はんだ粒子の内部は溶解するが、表面に形成された酸化被膜は、フラックスの融点（活性温度）に達していないので、除去されない。この状態で、電極部分の温度が先に、フラックスの融点（活性温度）に達するため、優先的に電極上に来たはんだ粒子の表面の酸化被膜が除去され、はんだ粒子が電極の表面上に濡れ拡がることができる。これにより、電極上に効率的にはんだ粒子を凝集させることができる。 Since the melting point of the flux is higher than the melting point of the solder, the solder particles can be efficiently aggregated on the electrode portion. This is because, when heat is applied at the time of joining, when the electrode formed on the connection target member is compared with the portion of the connection target member around the electrode, the thermal conductivity of the electrode portion is that of the connection target member portion around the electrode. Due to the fact that it is higher than the thermal conductivity, the temperature rise of the electrode portion is fast. At the stage where the melting point of the solder particles is exceeded, the inside of the solder particles dissolves, but the oxide film formed on the surface does not reach the melting point (activation temperature) of the flux and is not removed. In this state, since the temperature of the electrode portion first reaches the melting point (activation temperature) of the flux, the oxide film on the surface of the solder particles preferentially on the electrode is removed, and the solder particles are placed on the surface of the electrode. Can spread wet. Thereby, solder particles can be efficiently aggregated on the electrode.
　上記フラックスは、導電ペースト中に分散されていてもよく、はんだ粒子の表面上に付着していてもよい。 The flux may be dispersed in the conductive paste or may be adhered on the surface of the solder particles.
　上記フラックスは、加熱によりカチオンを放出するフラックスであることが好ましい。加熱によりカチオンを放出するフラックスの使用により、はんだ粒子を電極上により一層効率的に配置することができる。 The flux is preferably a flux that releases cations by heating. By using a flux that releases cations upon heating, the solder particles can be arranged more efficiently on the electrode.
　上記導電ペースト１００重量％中、上記フラックスの含有量は好ましくは０．５重量％以上、好ましくは３０重量％以下、より好ましくは２５重量％以下である。上記導電ペーストは、フラックスを含んでいなくてもよい。フラックスの含有量が上記下限以上及び上記上限以下であると、はんだ及び電極の表面に酸化被膜がより一層形成され難くなり、さらに、はんだ及び電極の表面に形成された酸化被膜をより一層効果的に除去できる。 In 100% by weight of the conductive paste, the content of the flux is preferably 0.5% by weight or more, preferably 30% by weight or less, more preferably 25% by weight or less. The conductive paste may not contain a flux. When the flux content is not less than the above lower limit and not more than the above upper limit, it becomes more difficult to form an oxide film on the surface of the solder and the electrode, and the oxide film formed on the surface of the solder and the electrode is more effective. Can be removed.
　（フィラー）
　上記導電ペーストには、フィラーを添加してもよい。フィラーは、有機フィラーであってもよく、無機フィラーであってもよい。フィラーの添加により、はんだ粒子の凝集する距離を抑制し、基板の全電極上に対して、はんだ粒子を均一に凝集させることができる。 (Filler)
A filler may be added to the conductive paste. The filler may be an organic filler or an inorganic filler. By adding the filler, the distance at which the solder particles aggregate can be suppressed, and the solder particles can be uniformly aggregated on all the electrodes of the substrate.
　上記導電ペースト１００重量％中、上記フィラーの含有量は好ましくは０重量％以上、好ましくは５重量％以下、より好ましくは２重量％以下、更に好ましくは１重量％以下である。上記フィラーの含有量が上記下限以上及び上記上限以下であると、はんだ粒子が電極上により一層効率的に配置される。 In 100% by weight of the conductive paste, the filler content is preferably 0% by weight or more, preferably 5% by weight or less, more preferably 2% by weight or less, and further preferably 1% by weight or less. When the content of the filler is not less than the above lower limit and not more than the above upper limit, the solder particles are more efficiently arranged on the electrode.
　（他の成分）
　上記導電ペーストは、必要に応じて、例えば、充填剤、増量剤、軟化剤、可塑剤、重合触媒、硬化触媒、着色剤、酸化防止剤、熱安定剤、光安定剤、紫外線吸収剤、滑剤、帯電防止剤及び難燃剤等の各種添加剤を含んでいてもよい。 (Other ingredients)
If necessary, the conductive paste is, for example, a filler, an extender, a softener, a plasticizer, a polymerization catalyst, a curing catalyst, a colorant, an antioxidant, a heat stabilizer, a light stabilizer, an ultraviolet absorber, and a lubricant. In addition, various additives such as an antistatic agent and a flame retardant may be included.
　（接続構造体及び接続構造体の製造方法）
　本発明に係る接続構造体は、少なくとも１つの第１の電極を表面に有する第１の接続対象部材と、少なくとも１つの第２の電極を表面に有する第２の接続対象部材と、上記第１の接続対象部材と、上記第２の接続対象部材とを接続している接続部とを備える。本発明に係る接続構造体では、上記接続部が、上述した導電ペーストにより形成されており、上述した導電ペーストの硬化物である。本発明に係る接続構造体では、上記接続部の材料が、上述した導電ペーストである。本発明に係る接続構造体では、上記第１の電極と上記第２の電極とが、上記接続部中のはんだ部により電気的に接続されている。上記スペーサは、上記第１の接続対象部材と上記第２の接続対象部材との双方に接触していることが好ましい。 (Connection structure and method of manufacturing connection structure)
A connection structure according to the present invention includes a first connection target member having at least one first electrode on the surface, a second connection target member having at least one second electrode on the surface, and the first The connection object member and the connection part which has connected the said 2nd connection object member are provided. In the connection structure according to the present invention, the connection portion is formed of the conductive paste described above, and is a cured product of the conductive paste described above. In the connection structure according to the present invention, the material of the connection portion is the conductive paste described above. In the connection structure according to the present invention, the first electrode and the second electrode are electrically connected by a solder portion in the connection portion. It is preferable that the spacer is in contact with both the first connection target member and the second connection target member.
　本発明に係る接続構造体の製造方法は、上述した導電ペーストを用いて、少なくとも１つの第１の電極を表面に有する第１の接続対象部材の表面上に、上記導電ペーストを配置する工程と、上記導電ペーストの上記第１の接続対象部材側とは反対の表面上に、少なくとも１つの第２の電極を表面に有する第２の接続対象部材を、上記第１の電極と上記第２の電極とが対向するように配置する工程と、上記はんだ粒子の融点以上かつ上記熱硬化性成分の硬化温度以上に上記導電ペーストを加熱することで、上記第１の接続対象部材と上記第２の接続対象部材とを接続している接続部を、上記導電ペーストにより形成し、かつ、上記第１の電極と上記第２の電極とを、上記接続部中のはんだ部により電気的に接続する工程とを備える。上記第１の接続対象部材と上記第２の接続対象部材との双方に上記スペーサを接触させることが好ましい。 The manufacturing method of the connection structure according to the present invention includes the step of disposing the conductive paste on the surface of the first connection target member having at least one first electrode on the surface using the conductive paste described above. The second connection target member having at least one second electrode on the surface of the conductive paste opposite to the first connection target member side is provided with the first electrode and the second connection target. The step of arranging the electrodes so as to face each other, and heating the conductive paste to a temperature equal to or higher than the melting point of the solder particles and equal to or higher than the curing temperature of the thermosetting component. A step of forming a connection part connecting the connection target member with the conductive paste, and electrically connecting the first electrode and the second electrode with a solder part in the connection part. With. The spacer is preferably brought into contact with both the first connection target member and the second connection target member.
　本発明に係る接続構造体及び本発明に係る接続構造体の製造方法では、特定の導電ペーストを用いているので、複数のはんだ粒子が第１の電極と第２の電極との間に集まりやすく、複数のはんだ粒子を電極（ライン）上に効率的に配置することができる。また、複数のはんだ粒子の一部が、電極が形成されていない領域（スペース）に配置され難く、電極が形成されていない領域に配置されるはんだ粒子の量をかなり少なくすることができる。従って、第１の電極と第２の電極との間の導通信頼性を高めることができる。しかも、接続されてはならない横方向に隣接する電極間の電気的な接続を防ぐことができ、絶縁信頼性を高めることができる。 In the connection structure according to the present invention and the method for manufacturing the connection structure according to the present invention, since a specific conductive paste is used, a plurality of solder particles are likely to gather between the first electrode and the second electrode. A plurality of solder particles can be efficiently arranged on the electrode (line). Moreover, it is difficult for some of the plurality of solder particles to be disposed in a region (space) where no electrode is formed, and the amount of solder particles disposed in a region where no electrode is formed can be considerably reduced. Therefore, the conduction reliability between the first electrode and the second electrode can be improved. In addition, it is possible to prevent electrical connection between laterally adjacent electrodes that should not be connected, and to improve insulation reliability.
　導通信頼性をより一層高める観点からは、上記第１の電極と上記第２の電極とを電気的に接続する際に、上記はんだ粒子の融点以上かつ上記熱硬化性成分の硬化温度以上に加熱し、複数の上記はんだ粒子を凝集させ、一体化させることが好ましい。 From the viewpoint of further improving the conduction reliability, when electrically connecting the first electrode and the second electrode, heating is performed at a temperature higher than the melting point of the solder particles and higher than the curing temperature of the thermosetting component. It is preferable that the plurality of solder particles are aggregated and integrated.
　また、複数のはんだ粒子を電極上に効率的に配置し、かつ電極が形成されていない領域に配置されるはんだ粒子の量をかなり少なくするためには、導電フィルムではなく、導電ペーストを用いる必要があることを、本発明者は見出した。 In addition, it is necessary to use a conductive paste instead of a conductive film in order to efficiently arrange a plurality of solder particles on an electrode and to considerably reduce the amount of solder particles arranged in a region where no electrode is formed. The present inventor has found that
　本発明では、複数のはんだ粒子を電極間に効率的に集める他の方法を更に採用してもよい。複数のはんだ粒子を電極間に効率的に集める方法としては、第１の接続対象部材と、第２の接続対象部材との間の導電ペーストに、熱を付与した際、熱により導電ペーストの粘度が低下することで、第１の接続対象部材と、第２の接続対象部材との間の導電ペーストの対流を発生させる方法等が挙げられる。この方法において、接続対象部材の表面の電極とそれ以外の表面部材との熱容量の差異により対流を発生させる方法、接続対象部材の水分を、熱により水蒸気として対流を発生させる方法、並びに第１の接続対象部材と第２の接続対象部材との温度差により対流を発生させる方法等が挙げられる。これにより、導電ペースト中のはんだ粒子を、電極の表面に効率的に移動させることができる。 In the present invention, another method for efficiently collecting a plurality of solder particles between the electrodes may be further employed. As a method for efficiently collecting a plurality of solder particles between electrodes, when heat is applied to the conductive paste between the first connection target member and the second connection target member, the viscosity of the conductive paste by heat is applied. The method of generating the convection of the electrically conductive paste between a 1st connection object member and a 2nd connection object member etc. is mentioned because it falls. In this method, a method of generating convection due to a difference in heat capacity between the electrode on the surface of the connection target member and the other surface member, a method of generating convection as water vapor from the heat of the connection target member, and the first Examples include a method of generating convection due to a temperature difference between the connection target member and the second connection target member. Thereby, the solder particles in the conductive paste can be efficiently moved to the surface of the electrode.
　本発明では、電極の表面に選択的にはんだ粒子を凝集させる方法を更に採用してもよい。電極の表面に選択的にはんだ粒子を凝集させる方法としては、溶融したはんだ粒子の濡れ性がよい電極材質と、溶融したはんだ粒子の濡れ性が悪いその他の表面材質とにより形成された接続対象部材を選択し、電極の表面に到達した溶融したはんだ粒子を選択的に電極に付着させ、その溶融したはんだ粒子に対し、別のはんだ粒子を溶融させて付着させる方法、熱伝導性がよい電極材質と、熱伝導性が悪いその他の表面材質とにより形成された接続対象部材を選択し、熱を付与した際に、電極の温度を他の表面部材に対し高くすることで、選択的に電極上ではんだを溶融させる方法、金属により形成された電極上に存在するマイナスの電荷に対して、プラスの電荷を持つように処理されたはんだ粒子を用いて、電極に選択的にはんだ粒子を凝集させる方法、並びに、親水性の金属表面を有する電極に対して、導電ペースト中のはんだ粒子以外の樹脂を疎水性とすることで、電極に選択的にはんだ粒子を凝集させる方法等が挙げられる。 In the present invention, a method of selectively aggregating solder particles on the surface of the electrode may be further employed. As a method of selectively agglomerating solder particles on the surface of the electrode, there is a connection target member formed of an electrode material having good wettability of molten solder particles and another surface material having poor wettability of molten solder particles. A method of selectively adhering molten solder particles that have reached the surface of the electrode to the electrode and then melting and adhering another solder particle to the molten solder particles, and an electrode material with good thermal conductivity And other surface materials with poor thermal conductivity are selected, and when heat is applied, the temperature of the electrode is raised relative to the other surface members to selectively In this method, the solder particles are selectively agglomerated on the electrodes by using solder particles that have been treated so as to have a positive charge with respect to the negative charges existing on the electrode formed of metal. Method of, and, the electrode having a hydrophilic metal surface, the resin other than the solder particles in the conductive paste by a hydrophobic, a method to aggregate selectively solder particles on the electrode, and the like.
　電極間でのはんだ部の厚みは、好ましくは１０μｍ以上、より好ましくは２０μｍ以上、好ましくは１００μｍ以下、より好ましくは８０μｍ以下である。電極の表面上のはんだ濡れ面積（電極の露出した面積１００％中のはんだが接している面積）は、好ましくは５０％以上、より好ましくは６０％以上、更に好ましくは７０％以上、好ましくは１００％以下である。 The thickness of the solder part between the electrodes is preferably 10 μm or more, more preferably 20 μm or more, preferably 100 μm or less, more preferably 80 μm or less. The solder wetted area on the surface of the electrode (area where the solder is in contact with 100% of the exposed area of the electrode) is preferably 50% or more, more preferably 60% or more, still more preferably 70% or more, preferably 100. % Or less.
　本発明に係る接続構造体の製造方法では、上記第２の接続対象部材を配置する工程及び上記接続部を形成する工程において、加圧を行わず、上記導電ペーストには、上記第２の接続対象部材の重量が加わるか、又は、上記第２の接続対象部材を配置する工程及び上記接続部を形成する工程の内の少なくとも一方において、加圧を行い、かつ、上記第２の接続対象部材を配置する工程及び上記接続部を形成する工程の双方において、加圧の圧力が１ＭＰａ未満であることが好ましい。１ＭＰａ以上の加圧の圧力を加えないことで、はんだ粒子の凝集がかなり促進される。接続対象部材の反りを抑える観点からは、本発明に係る接続構造体の製造方法では、上記第２の接続対象部材を配置する工程及び上記接続部を形成する工程の内の少なくとも一方において、加圧を行い、かつ、上記第２の接続対象部材を配置する工程及び上記接続部を形成する工程の双方において、加圧の圧力が１ＭＰａ未満であってもよい。加圧を行う場合に、上記第２の接続対象部材を配置する工程のみにおいて、加圧を行ってもよく、上記接続部を形成する工程のみにおいて、加圧を行ってもよく、上記第２の接続対象部材を配置する工程と上記接続部を形成する工程との双方において、加圧を行ってもよい。加圧の圧力が１ＭＰａ未満には、加圧していない場合が含まれる。加圧を行う場合に、加圧の圧力は、好ましくは０．９ＭＰａ以下、より好ましくは０．８ＭＰａ以下である。加圧の圧力が０．８ＭＰａ以下である場合に、加圧の圧力が０．８ＭＰａを超える場合と比べて、はんだ粒子の凝集がより一層顕著に促進される。 In the manufacturing method of the connection structure according to the present invention, in the step of arranging the second connection target member and the step of forming the connection portion, no pressure is applied, and the second connection is applied to the conductive paste. The weight of the target member is added, or pressure is applied in at least one of the step of arranging the second connection target member and the step of forming the connection portion, and the second connection target member It is preferable that the pressure of pressurization is less than 1 MPa in both the step of disposing and the step of forming the connecting portion. By not applying a pressure of 1 MPa or more, the aggregation of solder particles is considerably promoted. From the viewpoint of suppressing the warpage of the connection target member, in the method for manufacturing a connection structure according to the present invention, at least one of the step of arranging the second connection target member and the step of forming the connection portion, The pressure of pressurization may be less than 1 MPa in both the step of performing pressure and arranging the second connection target member and the step of forming the connection portion. When pressurization is performed, the pressurization may be performed only in the step of arranging the second connection target member, or the pressurization may be performed only in the step of forming the connection portion. Pressurization may be performed in both the step of arranging the connection target member and the step of forming the connection portion. The case where the pressure is less than 1 MPa includes the case where no pressure is applied. When pressurizing, the pressure of pressurization is preferably 0.9 MPa or less, more preferably 0.8 MPa or less. When the pressure of the pressurization is 0.8 MPa or less, the aggregation of the solder particles is further promoted more remarkably than when the pressure of the pressurization exceeds 0.8 MPa.
　本発明に係る接続構造体の製造方法では、上記第２の接続対象部材を配置する工程及び上記接続部を形成する工程において、加圧を行わず、上記導電ペーストには、上記第２の接続対象部材の重量が加わることが好ましく、上記第２の接続対象部材を配置する工程及び上記接続部を形成する工程において、上記導電ペーストには、上記第２の接続対象部材の重量の力を超える加圧圧力は加わらないことが好ましい。これらの場合には、複数のはんだ部において、はんだ量の均一性をより一層高めることができる。さらに、はんだ部の厚みをより一層効果的に厚くすることができ、複数のはんだ粒子が電極間に多く集まりやすくなり、複数のはんだ粒子を電極（ライン）上により一層効率的に配置することができる。また、複数のはんだ粒子の一部が、電極が形成されていない領域（スペース）に配置され難く、電極が形成されていない領域に配置されるはんだ粒子の量をより一層少なくすることができる。従って、電極間の導通信頼性をより一層高めることができる。しかも、接続されてはならない横方向に隣接する電極間の電気的な接続をより一層防ぐことができ、絶縁信頼性をより一層高めることができる。 In the manufacturing method of the connection structure according to the present invention, in the step of arranging the second connection target member and the step of forming the connection portion, no pressure is applied, and the second connection is applied to the conductive paste. The weight of the target member is preferably added, and in the step of arranging the second connection target member and the step of forming the connection portion, the conductive paste exceeds the weight force of the second connection target member. It is preferable that no pressure is applied. In these cases, the uniformity of the amount of solder can be further enhanced in the plurality of solder portions. Furthermore, the thickness of the solder portion can be increased more effectively, and a plurality of solder particles can be easily collected between the electrodes, and the plurality of solder particles can be arranged more efficiently on the electrodes (lines). it can. Moreover, it is difficult for some of the plurality of solder particles to be arranged in a region (space) where no electrode is formed, and the amount of solder particles arranged in a region where no electrode is formed can be further reduced. Therefore, the conduction reliability between the electrodes can be further enhanced. In addition, the electrical connection between the laterally adjacent electrodes that should not be connected can be further prevented, and the insulation reliability can be further improved.
　さらに、上記第２の接続対象部材を配置する工程及び上記接続部を形成する工程において、加圧を行わず、上記導電ペーストには、上記第２の接続対象部材の重量が加われば、接続部が形成される前に電極が形成されていない領域（スペース）に配置されていたはんだ粒子が第１の電極と第２の電極との間により一層集まりやすくなり、複数のはんだ粒子を電極（ライン）上により一層効率的に配置することができることも、本発明者は見出した。本発明では、導電フィルムではなく、導電ペーストを用いるという構成と、加圧を行わず、上記導電ペーストには、上記第２の接続対象部材の重量が加わるようにするという構成とを組み合わせて採用することには、本発明の効果をより一層高いレベルで得るために大きな意味がある。 Furthermore, in the step of arranging the second connection target member and the step of forming the connection portion, if no weight is applied and the weight of the second connection target member is added to the conductive paste, the connection portion The solder particles arranged in the region (space) where the electrode is not formed before the electrode is formed are more easily collected between the first electrode and the second electrode, so that the plurality of solder particles are separated from the electrode (line). The present inventor has also found that the above can be arranged more efficiently. In the present invention, a configuration in which a conductive paste is used instead of a conductive film and a configuration in which the weight of the second connection target member is added to the conductive paste without applying pressure are used in combination. This has a great meaning in order to obtain the effects of the present invention at a higher level.
　なお、ＷＯ２００８／０２３４５２Ａ１では、はんだ粉を電極表面に押し流して効率よく移動させる観点からは、接着時に所定の圧力で加圧するとよいことが記載されており、加圧圧力は、はんだ領域をさらに確実に形成する観点では、例えば、０ＭＰａ以上、好ましくは１ＭＰａ以上とすることが記載されており、更に、接着テープに意図的に加える圧力が０ＭＰａであっても、接着テープ上に配置された部材の自重により、接着テープに所定の圧力が加わってもよいことが記載されている。ＷＯ２００８／０２３４５２Ａ１では、接着テープに意図的に加える圧力が０ＭＰａであってもよいことは記載されているが、０ＭＰａを超える圧力を付与した場合と０ＭＰａとした場合との効果の差異については、何ら記載されていない。また、ＷＯ２００８／０２３４５２Ａ１では、フィルム状ではなく、ペースト状の導電ペーストを用いることの重要性についても何ら認識されていない。 In addition, WO2008 / 023452A1 describes that it is preferable to pressurize with a predetermined pressure at the time of bonding from the viewpoint of efficiently moving the solder powder to the electrode surface, and the pressurizing pressure further ensures the solder area. For example, it is described that the pressure is set to 0 MPa or more, preferably 1 MPa or more. Further, even if the pressure intentionally applied to the adhesive tape is 0 MPa, the member disposed on the adhesive tape It is described that a predetermined pressure may be applied to the adhesive tape by its own weight. In WO2008 / 023452A1, it is described that the pressure applied intentionally to the adhesive tape may be 0 MPa, but there is no difference between the effect when the pressure exceeding 0 MPa is applied and when the pressure is set to 0 MPa. Not listed. In addition, WO2008 / 023452A1 recognizes nothing about the importance of using a paste-like conductive paste instead of a film.
　また、導電フィルムではなく、導電ペーストを用いれば、導電ペーストの塗布量によって、接続部及びはんだ部の厚みを調整することが容易になる。一方で、導電フィルムでは、接続部の厚みを変更したり、調整したりするためには、異なる厚みの導電フィルムを用意したり、所定の厚みの導電フィルムを用意したりしなければならないという問題がある。また、導電フィルムでは、はんだの溶融温度で、導電フィルムの溶融粘度を十分に下げることができず、はんだ粒子の凝集が阻害されるという問題がある。 Also, if a conductive paste is used instead of a conductive film, it becomes easy to adjust the thicknesses of the connection part and the solder part depending on the amount of the conductive paste applied. On the other hand, in the conductive film, in order to change or adjust the thickness of the connection portion, it is necessary to prepare a conductive film having a different thickness or to prepare a conductive film having a predetermined thickness. There is. In addition, the conductive film has a problem that the melt viscosity of the conductive film cannot be sufficiently lowered at the melting temperature of the solder, and the aggregation of the solder particles is hindered.
　以下、図面を参照しつつ、本発明の具体的な実施形態を説明する。 Hereinafter, specific embodiments of the present invention will be described with reference to the drawings.
　図１は、本発明の一実施形態に係る導電ペーストを用いて得られる接続構造体を模式的に示す断面図である。 FIG. 1 is a cross-sectional view schematically showing a connection structure obtained using a conductive paste according to an embodiment of the present invention.
　図１に示す接続構造体１は、第１の接続対象部材２と、第２の接続対象部材３と、第１の接続対象部材２と第２の接続対象部材３とを接続している接続部４とを備える。接続部４は、熱硬化性化合物と、熱硬化剤と、複数のはんだ粒子と、複数のスペーサ５とを含む導電ペーストにより形成されている。上記熱硬化性化合物と上記熱硬化剤とは、熱硬化性成分である。 The connection structure 1 shown in FIG. 1 is a connection that connects a first connection target member 2, a second connection target member 3, and the first connection target member 2 and the second connection target member 3. Part 4. The connection portion 4 is formed of a conductive paste including a thermosetting compound, a thermosetting agent, a plurality of solder particles, and a plurality of spacers 5. The thermosetting compound and the thermosetting agent are thermosetting components.
　接続部４は、複数のはんだ粒子が集まり互いに接合したはんだ部４Ａと、熱硬化性成分が熱硬化された硬化物部４Ｂと、スペーサ５とを有する。 The connecting portion 4 includes a solder portion 4A in which a plurality of solder particles are gathered and joined to each other, a cured portion 4B in which a thermosetting component is thermally cured, and a spacer 5.
　第１の接続対象部材２は表面（上面）に、複数の第１の電極２ａを有する。第２の接続対象部材３は表面（下面）に、複数の第２の電極３ａを有する。第１の電極２ａと第２の電極３ａとが、はんだ部４Ａにより電気的に接続されている。従って、第１の接続対象部材２と第２の接続対象部材３とが、はんだ部４Ａにより電気的に接続されている。なお、接続部４において、第１の電極２ａと第２の電極３ａとの間に集まったはんだ部４Ａとは異なる領域（硬化物部４Ｂ部分）では、はんだは存在しない。はんだ部４Ａとは異なる領域（硬化物部４Ｂ部分）では、はんだ部４Ａと離れたはんだは存在しない。なお、少量であれば、第１の電極２ａと第２の電極３ａとの間に集まったはんだ部４Ａとは異なる領域（硬化物部４Ｂ部分）に、はんだが存在していてもよい。 The first connection object member 2 has a plurality of first electrodes 2a on the surface (upper surface). The second connection target member 3 has a plurality of second electrodes 3a on the surface (lower surface). The first electrode 2a and the second electrode 3a are electrically connected by the solder portion 4A. Therefore, the first connection target member 2 and the second connection target member 3 are electrically connected by the solder portion 4A. In the connection portion 4, no solder exists in a region (cured product portion 4B portion) different from the solder portion 4A gathered between the first electrode 2a and the second electrode 3a. In an area different from the solder part 4A (hardened product part 4B part), there is no solder separated from the solder part 4A. If the amount is small, the solder may be present in a region (cured product portion 4B portion) different from the solder portion 4A gathered between the first electrode 2a and the second electrode 3a.
　スペーサ５は、第１の接続対象部材２の第１の電極２ａと第２の接続対象部材３の第２の電極３ａとの双方に接している。スペーサ５により、第１の接続対象部材２と第２の接続対象部材３との間隔が規制されており、第１の電極２ａと第２の電極３ａとの間隔が規制されている。スペーサ５は、第１の接続対象部材２の第１の電極２ａが設けられていない領域と第２の接続対象部材３の第２の電極３ａが設けられていない領域の双方に接していてもよい。 The spacer 5 is in contact with both the first electrode 2 a of the first connection target member 2 and the second electrode 3 a of the second connection target member 3. The distance between the first connection target member 2 and the second connection target member 3 is regulated by the spacer 5, and the distance between the first electrode 2 a and the second electrode 3 a is regulated. Even if the spacer 5 is in contact with both the region where the first electrode 2a of the first connection target member 2 is not provided and the region where the second electrode 3a of the second connection target member 3 is not provided. Good.
　図１に示すように、接続構造体１では、第１の電極２ａと第２の電極３ａとの間に、複数のはんだ粒子が集まり、複数のはんだ粒子が溶融した後、はんだ粒子の溶融物が電極の表面を濡れ拡がった後に固化して、はんだ部４Ａが形成されている。このため、はんだ部４Ａと第１の電極２ａ、並びにはんだ部４Ａと第２の電極３ａとの接続面積が大きくなる。すなわち、はんだ粒子を用いることにより、導電性の外表面がニッケル、金又は銅等の金属である導電性粒子を用いた場合と比較して、はんだ部４Ａと第１の電極２ａ、並びにはんだ部４Ａと第２の電極３ａとの接触面積が大きくなる。このため、接続構造体１における導通信頼性及び接続信頼性が高くなる。なお、導電ペーストは、フラックスを含んでいてもよい。フラックスを用いた場合には、加熱により、一般にフラックスは次第に失活する。 As shown in FIG. 1, in the connection structure 1, a plurality of solder particles gather between the first electrode 2 a and the second electrode 3 a, and after the plurality of solder particles melt, After the electrode surface wets and spreads, it solidifies to form the solder portion 4A. For this reason, the connection area of 4 A of solder parts and the 1st electrode 2a, and 4 A of solder parts, and the 2nd electrode 3a becomes large. That is, by using the solder particles, the solder portion 4A, the first electrode 2a, and the solder portion are compared with the case where the conductive outer surface is made of a metal such as nickel, gold or copper. The contact area between 4A and the second electrode 3a increases. For this reason, the conduction | electrical_connection reliability and connection reliability in the connection structure 1 become high. Note that the conductive paste may contain a flux. When the flux is used, the flux is generally deactivated gradually by heating.
　なお、図１に示す接続構造体１では、はんだ部４Ａの全てが、第１，第２の電極２ａ，３ａ間の対向している領域に位置している。図３に示す変形例の接続構造体１Ｘは、接続部４Ｘのみが、図１に示す接続構造体１と異なる。接続部４Ｘは、はんだ部４ＸＡと硬化物部４ＸＢと、スペーサ５Ｘとを有する。接続構造体１Ｘのように、はんだ部４ＸＡの多くが、第１，第２の電極２ａ，３ａの対向している領域に位置しており、はんだ部４ＸＡの一部が第１，第２の電極２ａ，３ａの対向している領域から側方にはみ出していてもよい。第１，第２の電極２ａ，３ａの対向している領域から側方にはみ出しているはんだ部４ＸＡは、はんだ部４ＸＡの一部であり、はんだ部４ＸＡから離れたはんだではない。なお、本実施形態では、はんだ部から離れたはんだの量を少なくすることができるが、はんだ部から離れたはんだが硬化物部中に存在していてもよい。 In addition, in the connection structure 1 shown in FIG. 1, all of the solder portions 4A are located in the facing region between the first and second electrodes 2a and 3a. The connection structure 1X of the modification shown in FIG. 3 is different from the connection structure 1 shown in FIG. 1 only in the connection portion 4X. The connection portion 4X includes a solder portion 4XA, a cured product portion 4XB, and a spacer 5X. As in the connection structure 1X, most of the solder portions 4XA are located in regions where the first and second electrodes 2a and 3a are opposed to each other, and a part of the solder portion 4XA is first and second. You may protrude to the side from the area | region which electrode 2a, 3a has opposed. The solder part 4XA protruding laterally from the region where the first and second electrodes 2a and 3a are opposed is a part of the solder part 4XA and is not a solder separated from the solder part 4XA. In the present embodiment, the amount of solder away from the solder portion can be reduced, but the solder away from the solder portion may exist in the cured product portion.
　はんだ粒子の使用量を少なくすれば、接続構造体１を得ることが容易になる。はんだ粒子の使用量を多くすれば、接続構造体１Ｘを得ることが容易になる。なお、はんだが電極の表面に濡れ拡がっていればよく、必ずしも、はんだが上下の電極間に集まっていなくてもよい。 If the amount of solder particles used is reduced, the connection structure 1 can be easily obtained. If the amount of the solder particles used is increased, it becomes easy to obtain the connection structure 1X. Note that it is sufficient that the solder wets and spreads on the surface of the electrode, and the solder does not necessarily have to be gathered between the upper and lower electrodes.
　また、図４に示す接続構造体１Ｙのように、第１の電極２ａを表面に有し、かつ第１の電極２ａ側の第１の電極２ａがない領域に第１の凸部２ｙを有する第１の接続対象部材２Ｙと、第２の電極３ａを表面に有し、かつ第２の電極３ａ側の第２の電極３ａがない領域に第２の凸部３ｙを有する第２の接続対象部材３Ｙとを用いてもよい。第１の凸部２ｙは、第１の電極２ａよりも突出している。第２の凸部３ｙは、第２の電極３ａよりも突出している。第１の凸部２ｙと第２の凸部３ｙとの間隔は、第１の電極２ａと第２の電極３ａとの間隔よりも狭い。この接続構造体１Ｙでは、接続部４Ｙは、はんだ部４ＹＡと硬化物部４ＹＢと、スペーサ５Ｙとを有する。接続構造体１Ｙでは、スペーサ５Ｙは、第１の凸部２ｙと第２の凸部３ｙとの双方に接触している。結果として、第１の電極２ａと第２の電極３ａとの間隔がスペーサ５Ｙにより規制されている。 Further, like the connection structure 1Y shown in FIG. 4, the first electrode 2a is provided on the surface, and the first convex portion 2y is provided in a region where the first electrode 2a on the first electrode 2a side is absent. The second connection target having the first connection target member 2Y and the second electrode 3a on the surface and the second protrusion 3y in the region where the second electrode 3a on the second electrode 3a side is not present. The member 3Y may be used. The first convex part 2y protrudes from the first electrode 2a. The 2nd convex part 3y protrudes rather than the 2nd electrode 3a. The distance between the first protrusion 2y and the second protrusion 3y is narrower than the distance between the first electrode 2a and the second electrode 3a. In the connection structure 1Y, the connection portion 4Y includes a solder portion 4YA, a cured product portion 4YB, and a spacer 5Y. In the connection structure 1Y, the spacer 5Y is in contact with both the first protrusion 2y and the second protrusion 3y. As a result, the distance between the first electrode 2a and the second electrode 3a is regulated by the spacer 5Y.
　導通信頼性をより一層高める観点からは、上記第１の電極と上記接続部と上記第２の電極との積層方向に上記第１の電極と上記第２の電極との対向し合う部分をみたときに、上記第１の電極と上記第２の電極との対向し合う部分の面積１００％中の５０％以上（好ましくは６０％以上、より好ましくは７０％以上、更に好ましくは８０％以上、特に好ましくは９０％以上）に、上記接続部中のはんだ部が配置されていることが好ましい。 From the viewpoint of further improving the conduction reliability, the portion where the first electrode and the second electrode face each other in the stacking direction of the first electrode, the connection portion, and the second electrode is seen. Sometimes, 50% or more (preferably 60% or more, more preferably 70% or more, still more preferably 80% or more) of 100% of the area where the first electrode and the second electrode face each other. It is particularly preferable that the solder portion in the connection portion is disposed at 90% or more.
　導通信頼性をより一層高める観点からは、上記第１の電極と上記接続部と上記第２の電極との積層方向と直交する方向に上記第１の電極と上記第２の電極との対向し合う部分をみたときに、上記第１の電極と上記第２の電極との対向し合う部分に、上記接続部中のはんだ部の７０％以上が配置されていることが好ましい。 From the viewpoint of further improving the conduction reliability, the first electrode and the second electrode are opposed to each other in a direction orthogonal to the stacking direction of the first electrode, the connection portion, and the second electrode. It is preferable that 70% or more of the solder portion in the connection portion is disposed in a portion where the first electrode and the second electrode face each other when the matching portion is viewed.
　次に、本発明の一実施形態に係る導電ペーストを用いて、接続構造体１を製造する方法の一例を説明する。 Next, an example of a method for manufacturing the connection structure 1 using the conductive paste according to the embodiment of the present invention will be described.
　先ず、第１の電極２ａを表面（上面）に有する第１の接続対象部材２を用意する。次に、図２（ａ）に示すように、第１の接続対象部材２の表面上に、熱硬化性成分１１Ｂと、複数のはんだ粒子１１Ａと、スペーサ５とを含む導電ペースト１１を配置する（第１の工程）。第１の接続対象部材２の第１の電極２ａが設けられた表面上に、導電ペースト１１を配置する。導電ペースト１１の配置の後に、はんだ粒子１１Ａは、第１の電極２ａ（ライン）上と、第１の電極２ａが形成されていない領域（スペース）上との双方に配置されている。 First, the first connection target member 2 having the first electrode 2a on the surface (upper surface) is prepared. Next, as illustrated in FIG. 2A, the conductive paste 11 including the thermosetting component 11 </ b> B, the plurality of solder particles 11 </ b> A, and the spacer 5 is disposed on the surface of the first connection target member 2. (First step). The conductive paste 11 is disposed on the surface of the first connection target member 2 on which the first electrode 2a is provided. After the conductive paste 11 is disposed, the solder particles 11A are disposed both on the first electrode 2a (line) and on a region (space) where the first electrode 2a is not formed.
　導電ペースト１１の配置方法としては、特に限定されないが、ディスペンサーによる塗布、スクリーン印刷、及びインクジェット装置による吐出等が挙げられる。 The arrangement method of the conductive paste 11 is not particularly limited, and examples thereof include application with a dispenser, screen printing, and ejection with an inkjet device.
　また、第２の電極３ａを表面（下面）に有する第２の接続対象部材３を用意する。次に、図２（ｂ）に示すように、第１の接続対象部材２の表面上の導電ペースト１１において、導電ペースト１１の第１の接続対象部材２側とは反対側の表面上に、第２の接続対象部材３を配置する（第２の工程）。導電ペースト１１の表面上に、第２の電極３ａ側から、第２の接続対象部材３を配置する。このとき、第１の電極２ａと第２の電極３ａとを対向させる。 Moreover, the 2nd connection object member 3 which has the 2nd electrode 3a on the surface (lower surface) is prepared. Next, as shown in FIG. 2B, in the conductive paste 11 on the surface of the first connection target member 2, on the surface of the conductive paste 11 opposite to the first connection target member 2 side, The 2nd connection object member 3 is arrange | positioned (2nd process). On the surface of the conductive paste 11, the second connection target member 3 is disposed from the second electrode 3a side. At this time, the first electrode 2a and the second electrode 3a are opposed to each other.
　次に、はんだ粒子１１Ａの融点以上及び熱硬化性成分１１Ｂの硬化温度以上に導電ペースト１１を加熱する（第３の工程）。すなわち、はんだ粒子１１Ａの融点及び熱硬化性成分１１Ｂの硬化温度の内のより低い温度以上に、導電ペースト１１を加熱する。この加熱時には、電極が形成されていない領域に存在していたはんだ粒子１１Ａは、第１の電極２ａと第２の電極３ａとの間に集まる（自己凝集効果）。本実施形態では、導電フィルムではなく、導電ペーストを用いているために、更に導電ペーストが特定の組成を有するために、はんだ粒子１１Ａが、第１の電極２ａと第２の電極３ａとの間に効果的に集まる。また、はんだ粒子１１Ａは溶融し、互いに接合する。また、熱硬化性成分１１Ｂは熱硬化する。この結果、図２（ｃ）に示すように、第１の接続対象部材２と第２の接続対象部材３とを接続している接続部４を、導電ペースト１１により形成する。導電ペースト１１により接続部４が形成され、複数のはんだ粒子１１Ａが接合することによってはんだ部４Ａが形成され、熱硬化性成分１１Ｂが熱硬化することによって硬化物部４Ｂが形成される。はんだ粒子１１Ａが十分に移動すれば、第１の電極２ａと第２の電極３ａとの間に位置していないはんだ粒子１１Ａの移動が開始してから、第１の電極２ａと第２の電極３ａとの間にはんだ粒子１１Ａの移動が完了するまでに、温度を一定に保持しなくてもよい。 Next, the conductive paste 11 is heated above the melting point of the solder particles 11A and above the curing temperature of the thermosetting component 11B (third step). That is, the conductive paste 11 is heated to a temperature lower than the melting point of the solder particles 11A and the curing temperature of the thermosetting component 11B. At the time of this heating, the solder particles 11A that existed in the region where no electrode is formed gather between the first electrode 2a and the second electrode 3a (self-aggregation effect). In this embodiment, since the conductive paste is used instead of the conductive film, the conductive paste further has a specific composition, so that the solder particles 11A are disposed between the first electrode 2a and the second electrode 3a. To gather effectively. Also, the solder particles 11A are melted and joined together. Further, the thermosetting component 11B is thermoset. As a result, as shown in FIG. 2C, the connection portion 4 connecting the first connection target member 2 and the second connection target member 3 is formed with the conductive paste 11. The connection part 4 is formed by the conductive paste 11, the solder part 4A is formed by joining a plurality of solder particles 11A, and the cured part 4B is formed by thermosetting the thermosetting component 11B. If the solder particles 11A are sufficiently moved, the first electrode 2a and the second electrode are moved after the movement of the solder particles 11A not located between the first electrode 2a and the second electrode 3a starts. It is not necessary to keep the temperature constant until the movement of the solder particles 11A is completed.
　本実施形態では、上記第２の工程及び上記第３の工程において、加圧を行っていない。本実施形態では、導電ペースト１１には、第２の接続対象部材３の重量が加わる。このため、接続部４の形成時に、はんだ粒子１１Ａが、第１の電極２ａと第２の電極３ａとの間に効果的に集まる。また、接続部４Ｘは、はんだ部４ＸＡと硬化物部４ＸＢと、スペーサ５とを有する。はんだ粒子１１Ａの寄り集まりによって、スペーサ５が押し出されやすい。接続部４の形成時に、スペーサ５は、第１の接続対象部材２と第２の接続対象部材３との双方に接触させることができる。具体的には、接続部４の形成時に、スペーサ５は、第１の電極２ａと第２の電極３ａとの双方に接触させることができる。なお、上記第２の工程及び上記第３の工程の内の少なくとも一方において、加圧を行えば、はんだ粒子が第１の電極と第２の電極との間に集まろうとする作用が阻害される傾向が高くなる。このことは、本発明者によって見出された。 In this embodiment, no pressure is applied in the second step and the third step. In the present embodiment, the weight of the second connection target member 3 is added to the conductive paste 11. For this reason, when the connection part 4 is formed, the solder particles 11A are effectively collected between the first electrode 2a and the second electrode 3a. Further, the connection portion 4X includes a solder portion 4XA, a cured product portion 4XB, and a spacer 5. The spacers 5 are easily pushed out by the gathering of the solder particles 11A. When forming the connection portion 4, the spacer 5 can be brought into contact with both the first connection target member 2 and the second connection target member 3. Specifically, when forming the connection portion 4, the spacer 5 can be brought into contact with both the first electrode 2a and the second electrode 3a. In addition, if pressure is applied in at least one of the second step and the third step, the action of the solder particles trying to collect between the first electrode and the second electrode is hindered. The tendency to become higher. This has been found by the inventor.
　また、本実施形態では、加圧を行っていないため、導電ペーストを塗布した第１の接続対象部材に、第２の接続対象部材を重ね合わせた際に、第１の接続対象部材の電極と第２の接続対象部材の電極とのアライメントがずれた状態で、第１の接続対象部材と第２の接続対象部材とが重ね合わされた場合でも、そのずれを補正して、第１の接続対象部材の電極と第２の接続対象部材の電極とを接続させることができる（セルフアライメント効果）。これは、第１の接続対象部材の電極と第２の接続対象部材の電極との間に自己凝集した溶融したはんだが、第１の接続対象部材の電極と第２の接続対象部材の電極との間のはんだと導電ペーストのその他の成分とが接する面積が最小となる方がエネルギー的に安定になるため、その最小の面積となる接続構造であるアライメントのあった接続構造にする力が働くためである。この際、導電ペーストが硬化していないこと、及び、その温度、時間にて、導電ペーストのはんだ粒子以外の成分の粘度が十分低いことが望ましい。 Moreover, in this embodiment, since pressurization is not performed, when the second connection target member is superimposed on the first connection target member to which the conductive paste is applied, the electrode of the first connection target member Even when the first connection target member and the second connection target member are overlapped in a state where the alignment with the electrode of the second connection target member is shifted, the shift is corrected and the first connection target is corrected. The electrode of the member can be connected to the electrode of the second connection target member (self-alignment effect). This is because the molten solder self-aggregated between the electrode of the first connection target member and the electrode of the second connection target member is the electrode of the first connection target member and the electrode of the second connection target member. As the area where the solder and the other components of the conductive paste are in contact with each other is minimized, the area becomes more stable in terms of energy. Because. At this time, it is desirable that the conductive paste is not cured and that the viscosity of components other than the solder particles of the conductive paste is sufficiently low at that temperature and time.
　スペーサが、第１の接続対象部材と第２の接続対象部材との間に存在することで、第１の接続対象部材の電極と、第２の接続対象部材の電極との間の距離を十分確保することができる。これにより、はんだ粒子の凝集する空間を確保でき、はんだ粒子の凝集性を高めることがきる。さらに、第１の接続対象部材の電極と、第２の接続対象部材の電極との間に、十分なはんだ量を確保できることから、相対する電極がずれて重ね合わされた場合でも、セルフアライメント効果が発現しやすくなる。導電接続後の好ましい電極のずれ量に関しては、電極の幅をＬとした場合、好ましくは０Ｌ以上（０以上）、好ましくは０．９Ｌ以下、より好ましくは０．７５Ｌ以下である。また、電接続後の好ましいずれ量Ｘに関しては、スペーサの粒子径をＲとした場合、好ましくは０Ｒ以上（０以上）、好ましくは３Ｒ以下、より好ましくは２Ｒ以下である。 Since the spacer exists between the first connection target member and the second connection target member, the distance between the electrode of the first connection target member and the electrode of the second connection target member is sufficient. Can be secured. Thereby, the space where the solder particles aggregate can be secured, and the aggregation property of the solder particles can be improved. Furthermore, since a sufficient amount of solder can be secured between the electrode of the first connection target member and the electrode of the second connection target member, the self-alignment effect can be obtained even when the opposing electrodes are shifted and overlapped. It becomes easy to express. The preferred amount of electrode displacement after the conductive connection is preferably 0 L or more (0 or more), preferably 0.9 L or less, more preferably 0.75 L or less, where L is the electrode width. Further, the preferable deviation amount X after the electric connection is preferably 0R or more (0 or more), preferably 3R or less, more preferably 2R or less when the particle diameter of the spacer is R.
　はんだの融点温度での導電ペーストの粘度は、好ましくは５０Ｐａ・ｓ以下、より好ましくは１０Ｐａ・ｓ以下、更に好ましくは１Ｐａ・ｓ以下、好ましくは０．１Ｐａ・ｓ以上、より好ましくは０．２Ｐａ・ｓ以上である。所定の粘度以下であれば、はんだ粒子を効率的に凝集させることができ、所定の粘度以上であれば、接続部でのボイドを抑制し、接続部以外への導電ペーストのはみだしを抑制することができる。 The viscosity of the conductive paste at the melting point temperature of the solder is preferably 50 Pa · s or less, more preferably 10 Pa · s or less, still more preferably 1 Pa · s or less, preferably 0.1 Pa · s or more, more preferably 0.2 Pa. -It is more than s. If the viscosity is lower than the predetermined viscosity, the solder particles can be efficiently aggregated. If the viscosity is higher than the predetermined viscosity, the void at the connection portion is suppressed, and the protrusion of the conductive paste to other than the connection portion is suppressed. Can do.
　このようにして、図１に示す接続構造体１が得られる。なお、上記第２の工程と上記第３の工程とは連続して行われてもよい。また、上記第２の工程を行った後に、得られる第１の接続対象部材２と導電ペースト１１と第２の接続対象部材３との積層体を、加熱部に移動させて、上記第３の工程を行ってもよい。上記加熱を行うために、加熱部材上に上記積層体を配置してもよく、加熱された空間内に上記積層体を配置してもよい。 In this way, the connection structure 1 shown in FIG. 1 is obtained. The second step and the third step may be performed continuously. Moreover, after performing the said 2nd process, the laminated body of the obtained 1st connection object member 2, the electrically conductive paste 11, and the 2nd connection object member 3 is moved to a heating part, and said 3rd said You may perform a process. In order to perform the heating, the laminate may be disposed on a heating member, or the laminate may be disposed in a heated space.
　上記第３の工程における加熱温度は、はんだ粒子の融点以上及び熱硬化性成分の硬化温度以上であれば特に限定されない。上記加熱温度は、好ましくは１４０℃以上、より好ましくは１６０℃以上、好ましくは４５０℃以下、より好ましくは２５０℃以下、更に好ましくは２００℃以下である。 The heating temperature in the third step is not particularly limited as long as it is higher than the melting point of the solder particles and higher than the curing temperature of the thermosetting component. The heating temperature is preferably 140 ° C. or higher, more preferably 160 ° C. or higher, preferably 450 ° C. or lower, more preferably 250 ° C. or lower, and still more preferably 200 ° C. or lower.
　第３の工程の前に、溶融前のはんだ粒子の凝集を均一化するために、加熱工程を設けてよい。上記加熱工程における加熱温度は、好ましくは６０℃以上、より好ましくは８０℃以上、好ましくは１３０℃以下、より好ましくは１２０℃以下の温度条件にて、好ましくは５秒以上、好ましくは１２０秒以下保持する。この加熱工程によって、熱硬化性成分が熱により低粘度化し、溶融前のはんだ粒子が、凝集することで網目構造を形成し、第３の工程ではんだ粒子が溶融して凝集する際、凝集しないはんだ粒子を少なくすることができる。 Before the third step, a heating step may be provided in order to uniformize the aggregation of the solder particles before melting. The heating temperature in the heating step is preferably 60 ° C. or higher, more preferably 80 ° C. or higher, preferably 130 ° C. or lower, more preferably 120 ° C. or lower, preferably 5 seconds or longer, preferably 120 seconds or shorter. Hold. By this heating step, the thermosetting component is reduced in viscosity by heat, and the solder particles before melting are aggregated to form a network structure. When the solder particles are melted and aggregated in the third step, they do not aggregate. Solder particles can be reduced.
　第３の工程において、好ましくははんだの融点（℃）以上、より好ましくははんだの融点（℃）＋５℃以上、好ましくははんだの融点（℃）＋２０℃以下、より好ましくははんだの融点（℃）＋１０℃以下の温度にて、好ましくは１０秒以上、好ましくは１２０秒以下保持したのち、熱硬化性成分の硬化温度にあげてもよい。これにより、熱硬化性成分が硬化する前の、熱硬化性成分の粘度が低い状態にて、はんだ粒子の凝集を完了させることができ、より一層均一なはんだ粒子の凝集を行うことができる。 In the third step, preferably the melting point of the solder (° C.) or more, more preferably the melting point of the solder (° C.) + 5 ° C. or more, preferably the melting point of the solder (° C.) + 20 ° C. or less, more preferably the melting point of the solder (° C.). After holding at a temperature of + 10 ° C. or lower, preferably 10 seconds or longer, preferably 120 seconds or shorter, the temperature may be raised to the curing temperature of the thermosetting component. Thereby, the aggregation of the solder particles can be completed in a state where the viscosity of the thermosetting component is low before the thermosetting component is cured, and the solder particles can be more evenly aggregated.
　第３の工程における昇温速度は、３０℃からはんだ粒子の融点までの昇温に関して、好ましくは５０℃／秒以下、より好ましくは２０℃／秒以下、更に好ましくは１０℃／秒以下、好ましくは１℃／秒以上、より好ましくは５℃／秒以上である。昇温速度が上記下限以上であると、はんだ粒子の凝集がより一層均一になる。昇温速度が上記上限以下であると、熱硬化性成分の硬化の進行による過度の粘度上昇が抑えられ、はんだ粒子の凝集が阻害されにくくなる。 The rate of temperature increase in the third step is preferably 50 ° C./second or less, more preferably 20 ° C./second or less, further preferably 10 ° C./second or less, with respect to the temperature increase from 30 ° C. to the melting point of the solder particles. Is 1 ° C./second or more, more preferably 5 ° C./second or more. When the rate of temperature rise is equal to or higher than the above lower limit, the aggregation of solder particles becomes even more uniform. When the rate of temperature increase is equal to or less than the above upper limit, an excessive increase in viscosity due to the progress of curing of the thermosetting component is suppressed, and aggregation of solder particles is hardly inhibited.
　なお、上記第３の工程の後に、位置の修正や製造のやり直しを目的として、第１の接続対象部材又は第２の接続対象部材を、接続部から剥離することができる。この剥離を行うための加熱温度は、好ましくははんだ粒子の融点以上、より好ましくははんだ粒子の融点（℃）＋１０℃以上である。この剥離を行うための加熱温度は、はんだ粒子の融点（℃）＋１００℃以下であってもよい。 In addition, after the said 3rd process, a 1st connection object member or a 2nd connection object member can be peeled from a connection part for the purpose of correction of a position, or re-production. The heating temperature for performing this peeling is preferably not lower than the melting point of the solder particles, more preferably not lower than the melting point (° C.) of the solder particles + 10 ° C. The heating temperature for performing this peeling may be the melting point (° C.) of the solder particles + 100 ° C. or less.
　上記第３の工程における加熱方法としては、はんだ粒子の融点以上及び熱硬化性成分の硬化温度以上に、接続構造体全体を、リフロー炉を用いて又はオーブンを用いて加熱する方法や、接続構造体の接続部のみを局所的に加熱する方法が挙げられる。 As the heating method in the third step, a method of heating the entire connection structure using a reflow furnace or an oven above the melting point of the solder particles and the curing temperature of the thermosetting component, or a connection structure The method of heating only the connection part of a body locally is mentioned.
　局所的に加熱する方法に用いる器具としては、ホットプレート、熱風を付与するヒートガン、はんだゴテ、及び赤外線ヒーター等が挙げられる。 Examples of instruments used in the method of locally heating include a hot plate, a heat gun that applies hot air, a soldering iron, and an infrared heater.
　また、ホットプレートにて局所的に加熱する際、接続部直下は、熱伝導性の高い金属にて、その他の加熱することが好ましくない個所は、フッ素樹脂等の熱伝導性の低い材質にて、ホットプレート上面を形成することが好ましい。 In addition, when heating locally with a hot plate, the metal directly under the connection is made of a metal with high thermal conductivity, and other places where heating is not preferred are made of a material with low thermal conductivity such as a fluororesin. The upper surface of the hot plate is preferably formed.
　上記第１，第２の接続対象部材は、特に限定されない。上記第１，第２の接続対象部材としては、具体的には、半導体チップ、半導体パッケージ、ＬＥＤチップ、ＬＥＤパッケージ、コンデンサ及びダイオード等の電子部品、並びに樹脂フィルム、プリント基板、フレキシブルプリント基板、フレキシブルフラットケーブル、リジッドフレキシブル基板、ガラスエポキシ基板及びガラス基板等の回路基板などの電子部品等が挙げられる。上記第１，第２の接続対象部材は、電子部品であることが好ましい。 The first and second connection target members are not particularly limited. Specifically as said 1st, 2nd connection object member, electronic components, such as a semiconductor chip, a semiconductor package, LED chip, LED package, a capacitor | condenser, a diode, and a resin film, a printed circuit board, a flexible printed circuit board, flexible Examples include electronic components such as flat cables, rigid flexible substrates, glass epoxy substrates, and circuit boards such as glass substrates. The first and second connection target members are preferably electronic components.
　上記第１の接続対象部材及び上記第２の接続対象部材の内の少なくとも一方が、樹脂フィルム、フレキシブルプリント基板、フレキシブルフラットケーブル又はリジッドフレキシブル基板であることが好ましい。上記第２の接続対象部材が、樹脂フィルム、フレキシブルプリント基板、フレキシブルフラットケーブル又はリジッドフレキシブル基板であることが好ましい。樹脂フィルム、フレキシブルプリント基板、フレキシブルフラットケーブル及びリジッドフレキシブル基板は、柔軟性が高く、比較的軽量であるという性質を有する。このような接続対象部材の接続に導電フィルムを用いた場合には、はんだ粒子が電極上に集まりにくい傾向がある。これに対して、樹脂フィルム、フレキシブルプリント基板、フレキシブルフラットケーブル又はリジッドフレキシブル基板を用いたとしても、導電ペーストを用いてはんだ粒子を電極上に効率的に集めることで、電極間の導通信頼性を充分に高めることができる。樹脂フィルム、フレキシブルプリント基板、フレキシブルフラットケーブル又はリジッドフレキシブル基板を用いる場合に、半導体チップなどの他の接続対象部材を用いた場合と比べて、加圧を行わないことによる電極間の導通信頼性の向上効果がより一層効果的に得られる。 It is preferable that at least one of the first connection target member and the second connection target member is a resin film, a flexible printed board, a flexible flat cable, or a rigid flexible board. The second connection target member is preferably a resin film, a flexible printed board, a flexible flat cable, or a rigid flexible board. Resin films, flexible printed boards, flexible flat cables, and rigid flexible boards have the property of being highly flexible and relatively lightweight. When a conductive film is used for connection of such a connection object member, there exists a tendency for a solder particle not to gather on an electrode. On the other hand, even if a resin film, a flexible printed circuit board, a flexible flat cable, or a rigid flexible circuit board is used, the conductive particles are efficiently collected on the electrodes by using the conductive paste, thereby improving the conduction reliability between the electrodes. It can be raised sufficiently. When using a resin film, a flexible printed circuit board, a flexible flat cable, or a rigid flexible circuit board, the reliability of conduction between electrodes by not applying pressure compared to the case of using other connection target members such as a semiconductor chip. The improvement effect can be obtained more effectively.
　上記接続対象部材に設けられている電極としては、金電極、ニッケル電極、錫電極、アルミニウム電極、銅電極、モリブデン電極、銀電極、ＳＵＳ電極及びタングステン電極等の金属電極が挙げられる。上記接続対象部材がフレキシブルプリント基板である場合には、上記電極は金電極、ニッケル電極、錫電極、銀電極又は銅電極であることが好ましい。上記接続対象部材がガラス基板である場合には、上記電極はアルミニウム電極、銅電極、モリブデン電極、銀電極又はタングステン電極であることが好ましい。なお、上記電極がアルミニウム電極である場合には、アルミニウムのみで形成された電極であってもよく、金属酸化物層の表面にアルミニウム層が積層された電極であってもよい。上記金属酸化物層の材料としては、３価の金属元素がドープされた酸化インジウム及び３価の金属元素がドープされた酸化亜鉛等が挙げられる。上記３価の金属元素としては、Ｓｎ、Ａｌ及びＧａ等が挙げられる。 Examples of the electrode provided on the connection target member include metal electrodes such as a gold electrode, a nickel electrode, a tin electrode, an aluminum electrode, a copper electrode, a molybdenum electrode, a silver electrode, a SUS electrode, and a tungsten electrode. When the connection object member is a flexible printed board, the electrode is preferably a gold electrode, a nickel electrode, a tin electrode, a silver electrode, or a copper electrode. When the connection target member is a glass substrate, the electrode is preferably an aluminum electrode, a copper electrode, a molybdenum electrode, a silver electrode, or a tungsten electrode. In addition, when the said electrode is an aluminum electrode, the electrode formed only with aluminum may be sufficient and the electrode by which the aluminum layer was laminated | stacked on the surface of the metal oxide layer may be sufficient. Examples of the material for the metal oxide layer include indium oxide doped with a trivalent metal element and zinc oxide doped with a trivalent metal element. Examples of the trivalent metal element include Sn, Al, and Ga.
　上記第１の電極及び上記第２の電極が、エリアアレイ又はペリフェラルにて配置されていることが好ましい。電極が、エリアアレイ、ペリフェラルにて面にて配置されている場合にて、本発明の効果が一層効果的に発揮される。エリアアレイとは、接続対象部材の電極が配置されている面にて、格子状に電極が配置されている構造のことである。ペリフェラルとは、接続対象部材の外周部に電極が配置されている構造のことである。電極が櫛型に並んでいる構造の場合は、櫛に垂直な方向に沿ってはんだ粒子が凝集すればよいのに対して、上記構造では電極が配置されている面において、全面にて均一にはんだ粒子が凝集する必要があるため、従来の方法では、はんだ量が不均一になりやすいのに対して、本発明の方法では、本発明の効果が一層効果的に発揮される。 It is preferable that the first electrode and the second electrode are arranged in an area array or a peripheral. The effect of the present invention is more effectively exhibited when the electrodes are arranged on the surface of an area array or a peripheral. The area array is a structure in which electrodes are arranged in a grid pattern on the surface where the electrodes of the connection target members are arranged. The peripheral is a structure in which electrodes are arranged on the outer periphery of a connection target member. In the case of a structure in which the electrodes are arranged in a comb shape, the solder particles only have to be aggregated along the direction perpendicular to the comb, whereas in the above structure, the surface on which the electrodes are arranged is uniform over the entire surface. Since it is necessary for the solder particles to agglomerate, the amount of solder tends to be non-uniform in the conventional method, whereas in the method of the present invention, the effects of the present invention are more effectively exhibited.
　以下、実施例及び比較例を挙げて、本発明を具体的に説明する。本発明は、以下の実施例のみに限定されない。 Hereinafter, the present invention will be specifically described with reference to examples and comparative examples. The present invention is not limited only to the following examples.
　ポリマーＡ：
　ビスフェノールＦと１，６－ヘキサンジオールジグリシジルエーテル、及びビスフェノールＦ型エポキシ樹脂との反応物（ポリマーＡ）の合成：
　ビスフェノールＦ（４，４’－メチレンビスフェノールと２，４’－メチレンビスフェノールと２，２’－メチレンビスフェノールとを重量比で２：３：１で含む）１００重量部、１，６－ヘキサンジオールジグリシジルエーテル１３０重量部、及びビスフェノールＦ型エポキシ樹脂（ＤＩＣ社製「ＥＰＩＣＬＯＮ　ＥＸＡ－８３０ＣＲＰ」）５重量部、レゾルシノール型エポキシ化合物（ナガセケムテックス社製「ＥＸ－２０１」）１０重量部を、３つ口フラスコに入れ、窒素フロー下にて、１００℃で溶解させた。その後、水酸基とエポキシ基の付加反応触媒であるトリフェニルブチルホスホニウムブロミド０．１５重量部を添加し、窒素フロー下にて、１４０℃で４時間、付加重合反応させることにより、反応物（ポリマーＡ）を得た。 Polymer A:
Synthesis of reaction product (polymer A) of bisphenol F with 1,6-hexanediol diglycidyl ether and bisphenol F type epoxy resin:
100 parts by weight of bisphenol F (containing 4,4′-methylene bisphenol, 2,4′-methylene bisphenol and 2,2′-methylene bisphenol in a weight ratio of 2: 3: 1), 1,6-hexanediol Three parts: 130 parts by weight of glycidyl ether, 5 parts by weight of bisphenol F type epoxy resin (“EPICLON EXA-830CRP” manufactured by DIC) and 10 parts by weight of resorcinol type epoxy compound (“EX-201” manufactured by Nagase ChemteX) It put into the neck flask and it was made to melt | dissolve at 100 degreeC under nitrogen flow. Thereafter, 0.15 part by weight of triphenylbutylphosphonium bromide, which is a catalyst for addition reaction of hydroxyl group and epoxy group, was added and subjected to an addition polymerization reaction at 140 ° C. for 4 hours under a nitrogen flow to obtain a reaction product (Polymer A). )
　ＮＭＲにより、付加重合反応が進行したことを確認して、反応物（ポリマーＡ）が、ビスフェノールＦに由来する水酸基と１，６－ヘキサンジオールジグリシジルエーテル、及びビスフェノールＦ型エポキシ樹脂のエポキシ基とが結合した構造単位を主鎖に有し、かつエポキシ基を両末端に有することを確認した。 By confirming that the addition polymerization reaction has progressed by NMR, the reaction product (Polymer A) contains a hydroxyl group derived from bisphenol F, 1,6-hexanediol diglycidyl ether, and an epoxy group of bisphenol F type epoxy resin. It was confirmed that it has a structural unit bonded to the main chain and has an epoxy group at both ends.
　ＧＰＣにより得られた反応物（ポリマーＡ）の重量平均分子量は２８０００、数平均分子量は８０００であった。 The weight average molecular weight of the reaction product (polymer A) obtained by GPC was 28,000, and the number average molecular weight was 8,000.
　ポリマーＢ：両末端エポキシ基剛直骨格フェノキシ樹脂、三菱化学社製「ＹＸ６９００ＢＨ４５」、重量平均分子量１６０００ Polymer B: both ends epoxy group rigid skeleton phenoxy resin, “YX6900BH45” manufactured by Mitsubishi Chemical Corporation, weight average molecular weight 16000
　熱硬化性化合物１：レゾルシノール型エポキシ化合物、ナガセケムテックス社製「ＥＸ－２０１」 Thermosetting compound 1: Resorcinol type epoxy compound, “EX-201” manufactured by Nagase ChemteX Corporation
　熱硬化性化合物２：エポキシ化合物、ＤＩＣ社製「ＥＸＡ－４８５０－１５０」、分子量９００、エポキシ当量４５０ｇ／ｅｑ Thermosetting compound 2: Epoxy compound, “EXA-4850-150” manufactured by DIC, molecular weight 900, epoxy equivalent 450 g / eq
　熱硬化剤１：トリメチロールプロパントリス（３－メルカプトプロピネート）、ＳＣ有機化学社製「ＴＭＭＰ」 Thermosetting agent 1: Trimethylolpropane tris (3-mercaptopropinate), “TMMP” manufactured by SC Organic Chemical Co., Ltd.
　潜在性エポキシ熱硬化剤１：Ｔ＆Ｋ　ＴＯＫＡ社製「フジキュア７０００」 Latent epoxy thermosetting agent 1: T & K TOKA's “Fujicure 7000”
　フラックス１：グルタル酸、和光純薬工業社製、融点（活性温度）９６℃ Flux 1: Glutaric acid, manufactured by Wako Pure Chemical Industries, Ltd., melting point (activation temperature) 96 ° C.
　はんだ粒子１～３の作製方法：
　アニオンポリマー１を有するはんだ粒子：はんだ粒子本体２００ｇと、アジピン酸４０ｇと、アセトン７０ｇとを３つ口フラスコに秤量し、次にはんだ粒子本体の表面の水酸基とアジピン酸のカルボキシル基との脱水縮合触媒であるジブチル錫オキサイド０．３ｇを添加し、６０℃で４時間反応させた。その後、はんだ粒子をろ過することで回収した。 Method for producing solder particles 1 to 3:
Solder particles having anionic polymer 1: 200 g of solder particle main body, 40 g of adipic acid, and 70 g of acetone are weighed in a three-necked flask, and then dehydration condensation between the hydroxyl group on the surface of the solder particle main body and the carboxyl group of adipic acid 0.3 g of dibutyltin oxide as a catalyst was added and reacted at 60 ° C. for 4 hours. Thereafter, the solder particles were collected by filtration.
　回収したはんだ粒子と、アジピン酸５０ｇと、トルエン２００ｇと、パラトルエンスルホン酸０．３ｇとを３つ口フラスコに秤量し、真空引き、及び還流を行いながら、１２０℃で、３時間反応させた。この際、ディーンスターク抽出装置を用いて、脱水縮合により生成した水を除去しながら反応させた。 The collected solder particles, 50 g of adipic acid, 200 g of toluene, and 0.3 g of paratoluenesulfonic acid were weighed in a three-necked flask and reacted at 120 ° C. for 3 hours while evacuating and refluxing. . At this time, the reaction was carried out while removing water produced by dehydration condensation using a Dean-Stark extraction device.
　その後、ろ過によりはんだ粒子を回収し、ヘキサンにて洗浄し、乾燥した。その後、得られたはんだ粒子をボールミルで解砕した後、所定のＣＶ値となるように篩を選択した。 Thereafter, the solder particles were collected by filtration, washed with hexane, and dried. Thereafter, the obtained solder particles were crushed with a ball mill, and then a sieve was selected so as to obtain a predetermined CV value.
　（ゼータ電位測定）
　また、得られたはんだ粒子を、アニオンポリマー１を有するはんだ粒子０．０５ｇを、メタノール１０ｇに入れ、超音波処理をすることで、均一に分散させて、分散液を得た。この分散液を用いて、かつＢｅｃｋｍａｎ　Ｃｏｕｌｔｅｒ社製「Ｄｅｌｓａｍａｘ　ＰＲＯ」を用いて、電気泳動測定法にて、ゼータ電位を測定した。 (Zeta potential measurement)
Moreover, 0.05 g of solder particles having the anion polymer 1 were put in 10 g of methanol and the resulting solder particles were uniformly dispersed by ultrasonic treatment to obtain a dispersion. The zeta potential was measured by electrophoretic measurement using this dispersion and “Delsamax PRO” manufactured by Beckman Coulter.
　（アニオンポリマーの重量平均分子量）
　はんだ粒子の表面のアニオンポリマー１の重量平均分子量は、０．１Ｎの塩酸を用い、はんだを溶解した後、ポリマーをろ過により回収し、ＧＰＣにより求めた。 (Weight average molecular weight of anionic polymer)
The weight average molecular weight of the anionic polymer 1 on the surface of the solder particles was obtained by dissolving the solder using 0.1N hydrochloric acid, collecting the polymer by filtration, and determining by GPC.
　（はんだ粒子のＣＶ値）
　ＣＶ値を、レーザー回折式粒度分布測定装置（堀場製作所社製「ＬＡ－９２０」）にて、測定した。 (CV value of solder particles)
The CV value was measured with a laser diffraction particle size distribution analyzer (“LA-920” manufactured by Horiba, Ltd.).
　はんだ粒子１（ＳｎＢｉはんだ粒子、融点１３９℃、三井金属社製「ＳＴ－３」を選別したはんだ粒子本体を用い、表面処理を行ったアニオンポリマー１を有するはんだ粒子、平均粒子径４μｍ、ＣＶ値７％、表面のゼータ電位：＋０．６５ｍＶ、ポリマー分子量Ｍｗ＝６５００） Solder particle 1 (SnBi solder particle, melting point 139 ° C., solder particle body selected from “ST-3” manufactured by Mitsui Kinzoku Co., Ltd., surface-treated anionic polymer 1 solder particle, average particle diameter 4 μm, CV value 7%, zeta potential on the surface: +0.65 mV, polymer molecular weight Mw = 6500)
　はんだ粒子２（ＳｎＢｉはんだ粒子、融点１３９℃、三井金属社製「ＤＳ１０」を選別したはんだ粒子本体を用い、表面処理を行ったアニオンポリマー１を有するはんだ粒子、平均粒子径１３μｍ、ＣＶ値２０％、表面のゼータ電位：＋０．４８ｍＶ、ポリマー分子量Ｍｗ＝７０００） Solder particle 2 (SnBi solder particle, melting point 139 ° C., solder particle body selected from Mitsui Kinzoku “DS10”, surface-treated solder particle having anionic polymer 1, average particle diameter 13 μm, CV value 20% Surface zeta potential: +0.48 mV, polymer molecular weight Mw = 7000)
　はんだ粒子３（ＳｎＢｉはんだ粒子、融点１３９℃、三井金属社製「１０－２５」を選別したはんだ粒子本体を用い、表面処理を行ったアニオンポリマー１を有するはんだ粒子、平均粒子径２５μｍ、ＣＶ値１５％、表面のゼータ電位：＋０．４ｍＶ、ポリマー分子量Ｍｗ＝８０００） Solder particle 3 (SnBi solder particle, melting point 139 ° C., solder particle body selected from “10-25” manufactured by Mitsui Kinzoku Co., Ltd., surface-treated solder particle having anion polymer 1, average particle diameter 25 μm, CV value 15%, surface zeta potential: +0.4 mV, polymer molecular weight Mw = 8000)
　はんだ粒子４（ＳｎＢｉはんだ粒子、融点１３９℃、三井金属社製「ＳＴ－３」を選別したはんだ粒子本体を用い、表面処理を行ったアニオンポリマー１を有するはんだ粒子、平均粒子径３μｍ、ＣＶ値７％、表面のゼータ電位：＋０．６５ｍＶ、ポリマー分子量Ｍｗ＝６５００） Solder particles 4 (SnBi solder particles, melting point 139 ° C., solder particles main body selected from Mitsui Kinzoku “ST-3”, surface-treated solder particles having anionic polymer 1, average particle diameter 3 μm, CV value 7%, zeta potential on the surface: +0.65 mV, polymer molecular weight Mw = 6500)
　導電性粒子１：樹脂粒子の表面上に厚み１μｍの銅層が形成されており、該銅層の表面に厚み３μｍのはんだ層（錫：ビスマス＝４３重量％：５７重量％）が形成されている導電性粒子 Conductive particles 1: a copper layer having a thickness of 1 μm is formed on the surface of the resin particles, and a solder layer having a thickness of 3 μm (tin: bismuth = 43 wt%: 57 wt%) is formed on the surface of the copper layer. Conductive particles
　導電性粒子１の作製方法：
　平均粒子径１０μｍのジビニルベンゼン樹脂粒子（積水化学工業社製「ミクロパールＳＰ－２１０」）を無電解ニッケルめっきし、樹脂粒子の表面上に厚さ０．１μｍの下地ニッケルめっき層を形成した。次いで、下地ニッケルめっき層が形成された樹脂粒子を電解銅めっきし、厚さ１μｍの銅層を形成した。更に、錫及びビスマスを含有する電解めっき液を用いて、電解めっきし、厚さ３μｍのはんだ層を形成した。このようにして、樹脂粒子の表面上に厚み１μｍの銅層が形成されており、該銅層の表面に厚み３μｍのはんだ層（錫：ビスマス＝４３重量％：５７重量％）が形成されている導電性粒子１を作製した。 Production method of conductive particles 1:
Divinylbenzene resin particles having an average particle diameter of 10 μm (“Micropearl SP-210” manufactured by Sekisui Chemical Co., Ltd.) were subjected to electroless nickel plating to form a base nickel plating layer having a thickness of 0.1 μm on the surface of the resin particles. Next, the resin particles on which the base nickel plating layer was formed were subjected to electrolytic copper plating to form a 1 μm thick copper layer. Furthermore, electrolytic plating was performed using an electrolytic plating solution containing tin and bismuth to form a solder layer having a thickness of 3 μm. Thus, a 1 μm thick copper layer is formed on the surface of the resin particles, and a 3 μm thick solder layer (tin: bismuth = 43 wt%: 57 wt%) is formed on the surface of the copper layer. Conductive particles 1 were prepared.
　スペーサ１（平均粒子径２０μｍ、ＣＶ値５％、軟化点３３０℃、積水化学工業社製、ジビニルベンゼン架橋粒子、１０％Ｋ値４４００Ｎ／ｍｍ２、圧縮回復率５５％）
　スペーサ２（平均粒子径３０μｍ、ＣＶ値５％、軟化点３３０℃、積水化学工業社製、ジビニルベンゼン架橋粒子、１０％Ｋ値４２００Ｎ／ｍｍ２、圧縮回復率５４％）
　スペーサ３（平均粒子径５０μｍ、ＣＶ値５％、軟化点３３０℃、積水化学工業社製、ジビニルベンゼン架橋粒子、１０％Ｋ値４１００Ｎ／ｍｍ２、圧縮回復率５４％） Spacer 1 (average particle diameter 20 μm, CV value 5%, softening point 330 ° C., manufactured by Sekisui Chemical Co., Ltd., divinylbenzene crosslinked particles, 10% K value 4400 N / mm 2 , compression recovery rate 55%)
Spacer 2 (average particle diameter 30 μm, CV value 5%, softening point 330 ° C., Sekisui Chemical Co., Ltd., divinylbenzene crosslinked particles, 10% K value 4200 N / mm 2 , compression recovery rate 54%)
Spacer 3 (average particle diameter 50 μm, CV value 5%, softening point 330 ° C., manufactured by Sekisui Chemical Co., Ltd., divinylbenzene crosslinked particles, 10% K value 4100 N / mm 2 , compression recovery rate 54%)
　フェノキシ樹脂（新日鉄住金化学社製「ＹＰ－５０Ｓ」） Phenoxy resin (“YP-50S” manufactured by Nippon Steel & Sumikin Chemical Co., Ltd.)
　（実施例１～１０）
　（１）異方性導電ペーストの作製
　下記の表１に示す成分を下記の表１に示す配合量で配合して、異方性導電ペーストを得た。 (Examples 1 to 10)
(1) Preparation of anisotropic conductive paste The components shown in Table 1 below were blended in the blending amounts shown in Table 1 to obtain anisotropic conductive paste.
　（２）第１の接続構造体（Ｌ／Ｓ＝５０μｍ／５０μｍ）の作製
　Ｌ／Ｓが５０μｍ／５０μｍ、電極長さ３ｍｍの銅電極パターン（銅電極の厚み１２μｍ）を上面に有するガラスエポキシ基板（ＦＲ－４基板）（第１の接続対象部材）を用意した。また、Ｌ／Ｓが５０μｍ／５０μｍ、電極長さ３ｍｍの銅電極パターン（銅電極の厚み１２μｍ）を下面に有するフレキシブルプリント基板（第２の接続対象部材）を用意した。 (2) Production of first connection structure (L / S = 50 μm / 50 μm) Glass epoxy substrate having a copper electrode pattern (copper electrode thickness 12 μm) having an L / S of 50 μm / 50 μm and an electrode length of 3 mm on the upper surface (FR-4 substrate) (first connection target member) was prepared. Moreover, the flexible printed circuit board (2nd connection object member) which has a copper electrode pattern (thickness of a copper electrode 12 micrometers) of L / S 50 micrometers / 50 micrometers and electrode length 3mm on the lower surface was prepared.
　ガラスエポキシ基板とフレキシブルプリント基板との重ね合わせ面積は、１．５ｃｍ×３ｍｍとし、接続した電極数は７５対とした。 The overlapping area of the glass epoxy substrate and the flexible printed circuit board was 1.5 cm × 3 mm, and the number of connected electrodes was 75 pairs.
　上記ガラスエポキシ基板の上面に、作製直後の異方性導電ペーストを、ガラスエポキシ基板の電極上で厚さ１００μｍとなるように、メタルマスクを用い、スクリーン印刷にて塗工し、異方性導電ペースト層を形成した。次に、異方性導電ペースト層の上面に上記フレキシブルプリント基板を、電極同士が対向するように積層した。このとき、加圧を行わなかった。異方性導電ペースト層には、上記フレキシブルプリント基板の重量は加わる。その後、異方性導電ペースト層の温度が１９０℃となるように加熱しながら、はんだを溶融させ、かつ異方性導電ペースト層を１９０℃で１０秒硬化させ、第１の接続構造体を得た。 On the upper surface of the glass epoxy substrate, the anisotropic conductive paste immediately after production is applied by screen printing using a metal mask so that the thickness is 100 μm on the electrode of the glass epoxy substrate, and anisotropic conductive A paste layer was formed. Next, the flexible printed circuit board was laminated on the upper surface of the anisotropic conductive paste layer so that the electrodes face each other. At this time, no pressure was applied. The weight of the flexible printed board is added to the anisotropic conductive paste layer. Then, while heating the anisotropic conductive paste layer to 190 ° C., the solder is melted and the anisotropic conductive paste layer is cured at 190 ° C. for 10 seconds to obtain a first connection structure. It was.
　（３）第２の接続構造体（Ｌ／Ｓ＝７５μｍ／７５μｍ）の作製
　Ｌ／Ｓが７５μｍ／７５μｍ、電極長さ３ｍｍの銅電極パターン（銅電極の厚み１２μｍ）を上面に有するガラスエポキシ基板（ＦＲ－４基板）（第１の接続対象部材）を用意した。また、Ｌ／Ｓが７５μｍ／７５μｍ、電極長さ３ｍｍの銅電極パターン（銅電極の厚み１２μｍ）を下面に有するフレキシブルプリント基板（第２の接続対象部材）を用意した。 (3) Production of second connection structure (L / S = 75 μm / 75 μm) Glass epoxy substrate having a L / S of 75 μm / 75 μm and an electrode length of 3 mm on a copper electrode pattern (copper electrode thickness 12 μm) on the upper surface (FR-4 substrate) (first connection target member) was prepared. In addition, a flexible printed circuit board (second connection target member) having a L / S of 75 μm / 75 μm and an electrode length of 3 mm on the lower surface of a copper electrode pattern (copper electrode thickness 12 μm) was prepared.
　Ｌ／Ｓが異なる上記ガラスエポキシ基板及びフレキシブルプリント基板を用いたこと以外は第１の接続構造体の作製と同様にして、第２の接続構造体を得た。 2nd connection structure was obtained like manufacture of the 1st connection structure except having used the above-mentioned glass epoxy board and flexible printed circuit board from which L / S differs.
　（４）第３の接続構造体（Ｌ／Ｓ＝１００μｍ／１００μｍ）の作製
　Ｌ／Ｓが１００μｍ／１００μｍ、電極長さ３ｍｍの銅電極パターン（銅電極の厚み１２μｍ）を上面に有するガラスエポキシ基板（ＦＲ－４基板）（第１の接続対象部材）を用意した。また、Ｌ／Ｓが１００μｍ／１００μｍ、電極長さ３ｍｍの銅電極パターン（銅電極の厚み１２μｍ）を下面に有するフレキシブルプリント基板（第２の接続対象部材）を用意した。 (4) Production of third connection structure (L / S = 100 μm / 100 μm) Glass epoxy substrate having a copper electrode pattern (copper electrode thickness 12 μm) with L / S of 100 μm / 100 μm and electrode length of 3 mm on the upper surface (FR-4 substrate) (first connection target member) was prepared. Moreover, the flexible printed circuit board (2nd connection object member) which has a copper electrode pattern (thickness of copper electrode 12 micrometers) of L / S of 100 micrometers / 100 micrometers and electrode length 3mm on the lower surface was prepared.
　Ｌ／Ｓが異なる上記ガラスエポキシ基板及びフレキシブルプリント基板を用いたこと以外は第１の接続構造体の作製と同様にして、第３の接続構造体を得た。 3rd connection structure was obtained like manufacture of the 1st connection structure except having used the above-mentioned glass epoxy board and flexible printed circuit board from which L / S differs.
　（比較例１）
　下記の表１に示す成分を下記の表１に示す配合量で配合して、異方性導電ペーストを得た。得られた異方性導電ペーストを用いたこと以外は実施例１と同様にして、第１，第２，第３の接続構造体を得た。 (Comparative Example 1)
The components shown in Table 1 below were blended in the blending amounts shown in Table 1 below to obtain anisotropic conductive paste. First, second, and third connection structures were obtained in the same manner as in Example 1 except that the obtained anisotropic conductive paste was used.
　（比較例２）
　下記の表１に示す成分を下記の表１に示す配合量で配合して、異方性導電ペーストを得た。得られた異方性導電ペーストを用いたこと、加熱時に１ＭＰａの圧力を加えたこと以外は実施例１と同様にして、第１，第２，第３の接続構造体を得た。 (Comparative Example 2)
The components shown in Table 1 below were blended in the blending amounts shown in Table 1 below to obtain anisotropic conductive paste. First, second, and third connection structures were obtained in the same manner as in Example 1 except that the obtained anisotropic conductive paste was used and a pressure of 1 MPa was applied during heating.
　（比較例３）
　フェノキシ樹脂（新日鉄住金化学社製「ＹＰ－５０Ｓ」）をメチルエチルケトン（ＭＥＫ）に固形分が５０重量％となるように溶解させて、溶解液を得た。下記の表１に示すフェノキシ樹脂を除く成分を下記の表１に示す配合量と、上記溶解液の全量とを配合して、遊星式攪拌機を用いて２０００ｒｐｍで５分間攪拌した後、バーコーターを用いて乾燥後の厚みが３０μｍになるよう離型ＰＥＴ（ポリエチレンテレフタレート）フィルム上に塗工した。室温で真空乾燥することで、ＭＥＫを除去することにより、異方性導電フィルムを得た。 (Comparative Example 3)
A phenoxy resin (“YP-50S” manufactured by Nippon Steel & Sumikin Chemical Co., Ltd.) was dissolved in methyl ethyl ketone (MEK) so that the solid content was 50% by weight to obtain a solution. Ingredients other than the phenoxy resin shown in Table 1 below were blended with the blending amounts shown in Table 1 below and the total amount of the above solution, and after stirring for 5 minutes at 2000 rpm using a planetary stirrer, a bar coater was used. It was used and coated on a release PET (polyethylene terephthalate) film so that the thickness after drying was 30 μm. An anisotropic conductive film was obtained by removing MEK by vacuum drying at room temperature.
　異方性導電フィルムを用いたこと以外は実施例１と同様にして、第１，第２，第３の接続構造体を得た。 The 1st, 2nd, 3rd connection structure was obtained like Example 1 except having used an anisotropic conductive film.
　（比較例４，５）
　下記の表１に示す成分を下記の表１に示す配合量で配合して、異方性導電ペーストを得た。得られた異方性導電ペーストを用いたこと以外は実施例１と同様にして、第１，第２，第３の接続構造体を得た。 (Comparative Examples 4 and 5)
The components shown in Table 1 below were blended in the blending amounts shown in Table 1 below to obtain anisotropic conductive paste. First, second, and third connection structures were obtained in the same manner as in Example 1 except that the obtained anisotropic conductive paste was used.
　（評価）
　（１）粘度
　異方性導電ペーストの２５℃での粘度（η２５）を、Ｅ型粘度計（東機産業社製）を用いて、２５℃及び５ｒｐｍの条件で測定した。 (Evaluation)
(1) Viscosity The viscosity (η25) at 25 ° C. of the anisotropic conductive paste was measured under the conditions of 25 ° C. and 5 rpm using an E-type viscometer (manufactured by Toki Sangyo Co., Ltd.).
　（２）はんだ部の厚み
　得られた接続構造体を断面観察することにより、上下の電極が間に位置しているはんだ部の厚みを評価した。 (2) Thickness of solder part By observing a cross section of the obtained connection structure, the thickness of the solder part between which the upper and lower electrodes are positioned was evaluated.
　（３）セルフアライメント性
　第３の接続構造体の作製において、ガラスエポキシ基板の電極と、フレキシブルプリント基板の電極とのずらし量を、２５μｍ（第４の接続構造体用）、５０μｍ（第５の接続構造体用）、７５μｍ（第６の接続構造体用）、９０μｍ（第７の接続構造体用）として、重ね合わせたこと以外は同様にして、第４～第７の接続構造体を得た。 (3) Self-alignment property In the production of the third connection structure, the shift amount between the electrode of the glass epoxy substrate and the electrode of the flexible printed board is set to 25 μm (for the fourth connection structure), 50 μm (for the fifth connection structure). For connection structure), 75 μm (for the sixth connection structure), and 90 μm (for the seventh connection structure), the fourth to seventh connection structures are obtained in the same manner except for superposition. It was.
　得られた第４～第７の接続構造体のガラスエポキシ基板の電極と、フレキシブルプリント基板の電極とのずれ量を測定した。第４～第７の接続構造体を２５個作製し、それぞれの接続構造体の両端に位置する電極にて、上下電極のずれ量を測定し、その測定値の平均値を求めた。セルフアライメント性を下記の基準で判定した。 The amount of deviation between the electrodes of the glass epoxy substrate and the electrodes of the flexible printed circuit board of the obtained fourth to seventh connection structures was measured. Twenty-five fourth to seventh connection structures were produced, and the amount of displacement between the upper and lower electrodes was measured at the electrodes located at both ends of each connection structure, and the average value of the measured values was obtained. Self-alignment was determined according to the following criteria.
　○○：ずれ量の平均値が１０μｍ未満
　○：ずれ量の平均値が１０μｍ以上、２５μｍ未満
　△：ずれ量の平均値が２５μｍ以上、５０μｍ未満
　×：ずれ量の平均値が５０μｍ以上 ◯: Average deviation amount is less than 10 μm ○: Average deviation amount is 10 μm or more and less than 25 μm Δ: Average deviation amount is 25 μm or more and less than 50 μm ×: Average deviation amount is 50 μm or more
　（４）電極上のはんだの配置精度１
　得られた第１，第２，第３の接続構造体において、第１の電極と接続部と第２の電極との積層方向に第１の電極と第２の電極との対向し合う部分をみたときに、第１の電極と第２の電極との対向し合う部分の面積１００％中の、接続部中のはんだ部が配置されている面積の割合Ｘを評価した。電極上のはんだの配置精度１を下記の基準で判定した。 (4) Solder placement accuracy on electrode 1
In the obtained first, second, and third connection structures, a portion where the first electrode and the second electrode face each other in the stacking direction of the first electrode, the connection portion, and the second electrode is provided. When viewed, the ratio X of the area where the solder portion in the connection portion is arranged in the area of 100% of the portion where the first electrode and the second electrode face each other was evaluated. The solder placement accuracy 1 on the electrode was determined according to the following criteria.
　［電極上のはんだの配置精度１の判定基準］
　○○：割合Ｘが７０％以上
　○：割合Ｘが６０％以上、７０％未満
　△：割合Ｘが５０％以上、６０％未満
　×：割合Ｘが５０％未満 [Criteria for solder placement accuracy 1 on electrode]
○○: Ratio X is 70% or more ○: Ratio X is 60% or more and less than 70% Δ: Ratio X is 50% or more and less than 60% X: Ratio X is less than 50%
　（５）電極上のはんだの配置精度２
　得られた第１，第２，第３の接続構造体において、第１の電極と接続部と第２の電極との積層方向と直交する方向に第１の電極と第２の電極との対向し合う部分をみたときに、接続部中のはんだ部１００％中、第１の電極と第２の電極との対向し合う部分に配置されている接続部中のはんだ部の割合Ｙを評価した。電極上のはんだの配置精度２を下記の基準で判定した。 (5) Solder placement accuracy on electrode 2
In the obtained first, second, and third connection structures, the first electrode and the second electrode are opposed to each other in a direction orthogonal to the stacking direction of the first electrode, the connection portion, and the second electrode. When looking at the mating part, the ratio Y of the solder part in the connecting part arranged in the part where the first electrode and the second electrode face each other in 100% of the solder part in the connecting part was evaluated. . The solder placement accuracy 2 on the electrode was determined according to the following criteria.
　［電極上のはんだの配置精度２の判定基準］
　○○：割合Ｙが９９％以上
　○：割合Ｙが９０％以上、９９％未満
　△：割合Ｙが７０％以上、９０％未満
　×：割合Ｙが７０％未満 [Criteria for solder placement accuracy 2 on electrode]
◯: Ratio Y is 99% or more ○: Ratio Y is 90% or more and less than 99% △: Ratio Y is 70% or more and less than 90% X: Ratio Y is less than 70%
　（６）上下の電極間の導通信頼性
　得られた第１，第２，第３の接続構造体（ｎ＝１５個）において、上下の電極間の１接続箇所当たりの接続抵抗をそれぞれ、４端子法により、測定した。接続抵抗の平均値を算出した。なお、電圧＝電流×抵抗の関係から、一定の電流を流した時の電圧を測定することにより接続抵抗を求めることができる。導通信頼性を下記の基準で判定した。 (6) Conduction reliability between upper and lower electrodes In the obtained first, second, and third connection structures (n = 15), the connection resistance per connection portion between the upper and lower electrodes is 4 respectively. It was measured by the terminal method. The average value of connection resistance was calculated. Note that the connection resistance can be obtained by measuring the voltage when a constant current is passed from the relationship of voltage = current × resistance. The conduction reliability was determined according to the following criteria.
　［導通信頼性の判定基準］
　○○：接続抵抗の平均値が５０ｍΩ以下
　○：接続抵抗の平均値が５０ｍΩを超え、７０ｍΩ以下
　△：接続抵抗の平均値が７０ｍΩを超え、１００ｍΩ以下
　×：接続抵抗の平均値が１００ｍΩを超える、又は接続不良が生じている [Judgment criteria for conduction reliability]
◯: Average connection resistance is 50 mΩ or less ○: Average connection resistance exceeds 50 mΩ, 70 mΩ or less △: Average connection resistance exceeds 70 mΩ, 100 mΩ or less ×: Average connection resistance exceeds 100 mΩ Or there is a bad connection
　（７）隣接する電極間の絶縁信頼性
　得られた第１，第２，第３の接続構造体（ｎ＝１５個）において、８５℃、湿度８５％の雰囲気中に１００時間放置後、隣接する電極間に、５Ｖを印加し、抵抗値を２５箇所で測定した。絶縁信頼性を下記の基準で判定した。 (7) Insulation reliability between adjacent electrodes In the obtained first, second, and third connection structures (n = 15), they were left in an atmosphere of 85 ° C. and 85% humidity for 100 hours and then adjacent to each other. 5V was applied between the electrodes to be measured, and the resistance value was measured at 25 locations. Insulation reliability was judged according to the following criteria.
　［絶縁信頼性の判定基準］
　○○：接続抵抗の平均値が１０７Ω以上
　○：接続抵抗の平均値が１０６Ω以上、１０７Ω未満
　△：接続抵抗の平均値が１０５Ω以上、１０６Ω未満
　×：接続抵抗の平均値が１０５Ω未満 [Criteria for insulation reliability]
◯: Average value of connection resistance is 10 7 Ω or more ○: Average value of connection resistance is 10 6 Ω or more, less than 10 7 Ω △: Average value of connection resistance is 10 5 Ω or more, less than 10 6 Ω ×: Connection The average resistance is less than 10 5 Ω
　（８）上下の電極間の位置ずれ
　得られた第１，第２，第３の接続構造体において、第１の電極と接続部と第２の電極との積層方向に第１の電極と第２の電極との対向し合う部分をみたときに、第１の電極の中心線と第２の電極の中心線とが揃っているか否か、並びに位置ずれの距離を評価した。上下の電極間の位置ずれを下記の基準で判定した。 (8) Position shift between upper and lower electrodes In the obtained first, second, and third connection structures, the first electrode and the second electrode are stacked in the stacking direction of the first electrode, the connection portion, and the second electrode. Whether the center line of the first electrode and the center line of the second electrode were aligned when the portion facing the two electrodes was viewed, and the distance of the positional deviation were evaluated. The positional deviation between the upper and lower electrodes was determined according to the following criteria.
　［上下の電極間の位置ずれの判定基準］
　○○：位置ずれが１５μｍ未満
　○：位置ずれが１５μｍ以上、２５μｍ未満
　△：位置ずれが２５μｍ以上、４０μｍ未満
　×：位置ずれが４０μｍ以上 [Criteria for misregistration between upper and lower electrodes]
○: Misalignment is less than 15 μm ○: Misalignment is 15 μm or more and less than 25 μm Δ: Misalignment is 25 μm or more and less than 40 μm ×: Misalignment is 40 μm or more
　詳細及び結果を下記の表１，２に示す。 Details and results are shown in Tables 1 and 2 below.
Figure JPOXMLDOC01-appb-T000001
Figure JPOXMLDOC01-appb-T000001
Figure JPOXMLDOC01-appb-T000002
Figure JPOXMLDOC01-appb-T000002
　フレキシブルプリント基板にかえて、樹脂フィルム、フレキシブルフラットケーブル及びリジッドフレキシブル基板を用いた場合でも、同様の傾向が見られた。 The same tendency was observed when using a resin film, a flexible flat cable, and a rigid flexible board instead of the flexible printed board.
　１，１Ｘ，１Ｙ…接続構造体
　２，２Ｙ…第１の接続対象部材
　２ａ…第１の電極
　２ｙ…第１の凸部
　３，３Ｙ…第２の接続対象部材
　３ａ…第２の電極
　３ｙ…第２の凸部
　４，４Ｘ，４Ｙ…接続部
　４Ａ，４ＸＡ，４ＹＡ…はんだ部
　４Ｂ，４ＸＢ，４ＹＢ…硬化物部
　５，５Ｘ，５Ｙ…スペーサ
　１１…導電ペースト
　１１Ａ…はんだ粒子
　１１Ｂ…熱硬化性成分 DESCRIPTION OF SYMBOLS 1,1X, 1Y ... Connection structure 2, 2Y ... 1st connection object member 2a ... 1st electrode 2y ... 1st convex part 3, 3Y ... 2nd connection object member 3a ... 2nd electrode 3y ... 2nd convex part 4, 4X, 4Y ... Connection part 4A, 4XA, 4YA ... Solder part 4B, 4XB, 4YB ... Hardened | cured material part 5, 5X, 5Y ... Spacer 11 ... Conductive paste 11A ... Solder particle 11B ... Thermosetting component

Claims (15)

  1. 　第１の電極を表面に有する第１の接続対象部材と第２の電極を表面に有する第２の接続対象部材とを接続し、前記第１の電極と前記第２の電極とを電気的に接続するために用いられる導電ペーストであって、
    　熱硬化性成分と、複数のはんだ粒子と、融点が２５０℃以上である複数のスペーサとを含み、
    　前記スペーサの平均粒子径は、前記はんだ粒子の平均粒子径よりも大きい、導電ペースト。     A first connection object member having a first electrode on the surface is connected to a second connection object member having a second electrode on the surface, and the first electrode and the second electrode are electrically connected A conductive paste used to connect,
    A thermosetting component, a plurality of solder particles, and a plurality of spacers having a melting point of 250 ° C. or higher,
    The electrically conductive paste whose average particle diameter of the said spacer is larger than the average particle diameter of the said solder particle.
  2. 　前記スペーサが絶縁性粒子である、請求項１に記載の導電ペースト。 The conductive paste according to claim 1, wherein the spacer is an insulating particle.
  3. 　前記導電ペーストは、前記スペーサが、前記第１の接続対象部材と前記第２の接続対象部材との双方に接するように用いられる、請求項１又は２に記載の導電ペースト。 The conductive paste according to claim 1 or 2, wherein the conductive paste is used so that the spacer is in contact with both the first connection target member and the second connection target member.
  4. 　前記導電ペーストは、前記第１の電極と前記第２の電極とを電気的に接続する際に、前記はんだ粒子の融点以上かつ前記熱硬化性成分の硬化温度以上に加熱し、複数の前記はんだ粒子を凝集させ、一体化させて用いられる、請求項１～３のいずれか１項に記載の導電ペースト。 When electrically connecting the first electrode and the second electrode, the conductive paste is heated to a temperature equal to or higher than a melting point of the solder particles and a temperature equal to or higher than a curing temperature of the thermosetting component. The conductive paste according to any one of claims 1 to 3, which is used by aggregating and integrating particles.
  5. 　前記スペーサの平均粒子径の、前記はんだ粒子の平均粒子径に対する比が１．１以上、１５以下である、請求項１～４のいずれか１項に記載の導電ペースト。 The conductive paste according to any one of claims 1 to 4, wherein a ratio of an average particle diameter of the spacer to an average particle diameter of the solder particles is 1.1 or more and 15 or less.
  6. 　前記スペーサの含有量が０．１重量％以上、１０重量％以下である、請求項１～５のいずれか１項に記載の導電ペースト。 The conductive paste according to any one of claims 1 to 5, wherein the spacer content is 0.1 wt% or more and 10 wt% or less.
  7. 　前記はんだ粒子の平均粒子径が１μｍ以上、４０μｍ以下である、請求項１～６のいずれか１項に記載の導電ペースト。 The conductive paste according to any one of claims 1 to 6, wherein an average particle size of the solder particles is 1 µm or more and 40 µm or less.
  8. 　前記はんだ粒子の含有量が１０重量％以上、８０重量％以下である、請求項１～７のいずれか１項に記載の導電ペースト。 The conductive paste according to any one of claims 1 to 7, wherein a content of the solder particles is 10 wt% or more and 80 wt% or less.
  9. 　前記はんだ粒子の重量％単位での含有量の、前記スペーサの重量％単位での含有量に対する比が、２以上、１００以下である、請求項１～８のいずれか１項に記載の導電ペースト。 The conductive paste according to any one of claims 1 to 8, wherein a ratio of the content of the solder particles in units of wt% to the content of the spacers in units of wt% is 2 or more and 100 or less. .
  10. 　少なくとも１つの第１の電極を表面に有する第１の接続対象部材と、
    　少なくとも１つの第２の電極を表面に有する第２の接続対象部材と、
    　前記第１の接続対象部材と、前記第２の接続対象部材とを接続している接続部とを備え、
    　前記接続部の材料が、請求項１～９のいずれか１項に記載の導電ペーストであり、
    　前記第１の電極と前記第２の電極とが、前記接続部中のはんだ部により電気的に接続されており、
    　前記スペーサが、前記第１の接続対象部材と前記第２の接続対象部材との双方に接触している、接続構造体。     A first connection target member having at least one first electrode on its surface;
    A second connection target member having at least one second electrode on its surface;
    A connecting portion connecting the first connection target member and the second connection target member;
    The material of the connection part is the conductive paste according to any one of claims 1 to 9,
    The first electrode and the second electrode are electrically connected by a solder part in the connection part,
    The connection structure in which the spacer is in contact with both the first connection target member and the second connection target member.
  11. 　前記第２の接続対象部材が、樹脂フィルム、フレキシブルプリント基板、フレキシブルフラットケーブル又はリジッドフレキシブル基板である、請求項１０に記載の接続構造体。 The connection structure according to claim 10, wherein the second connection target member is a resin film, a flexible printed board, a flexible flat cable, or a rigid flexible board.
  12. 　請求項１～９のいずれか１項に記載の導電ペーストを用いて、少なくとも１つの第１の電極を表面に有する第１の接続対象部材の表面上に、前記導電ペーストを配置する工程と、
    　前記導電ペーストの前記第１の接続対象部材側とは反対の表面上に、少なくとも１つの第２の電極を表面に有する第２の接続対象部材を、前記第１の電極と前記第２の電極とが対向するように配置する工程と、
    　前記はんだ粒子の融点以上かつ前記熱硬化性成分の硬化温度以上に前記導電ペーストを加熱することで、前記第１の接続対象部材と前記第２の接続対象部材とを接続している接続部を、前記導電ペーストにより形成し、かつ、前記第１の電極と前記第２の電極とを、前記接続部中のはんだ部により電気的に接続し、前記第１の接続対象部材と前記第２の接続対象部材との双方に前記スペーサを接触させる工程とを備える、接続構造体の製造方法。     Using the conductive paste according to any one of claims 1 to 9, disposing the conductive paste on a surface of a first connection target member having at least one first electrode on the surface;
    On the surface opposite to the first connection target member side of the conductive paste, a second connection target member having at least one second electrode on the surface, the first electrode and the second electrode And a step of arranging so as to face each other,
    By connecting the first connection target member and the second connection target member by heating the conductive paste above the melting point of the solder particles and above the curing temperature of the thermosetting component, The first paste and the second electrode are electrically connected by a solder portion in the connection portion, and the first connection target member and the second electrode are formed by the conductive paste. The manufacturing method of a connection structure provided with the process of making the said spacer contact with both to-be-connected members.
  13. 　前記第１の電極と前記第２の電極とを電気的に接続する際に、前記はんだ粒子の融点以上かつ前記熱硬化性成分の硬化温度以上に加熱し、複数の前記はんだ粒子を凝集させ、一体化させる、請求項１２に記載の接続構造体の製造方法。 When electrically connecting the first electrode and the second electrode, heating above the melting point of the solder particles and above the curing temperature of the thermosetting component, aggregating a plurality of the solder particles, The manufacturing method of the connection structure of Claim 12 made to integrate.
  14. 　前記第２の接続対象部材を配置する工程及び前記接続部を形成する工程において、加圧を行わず、前記導電ペーストには、前記第２の接続対象部材の重量が加わる、請求項１２又は１３に記載の接続構造体の製造方法。 The weight of the second connection target member is added to the conductive paste without applying pressure in the step of arranging the second connection target member and the step of forming the connection part. The manufacturing method of the connection structure of description.
  15. 　前記第２の接続対象部材が、樹脂フィルム、フレキシブルプリント基板、フレキシブルフラットケーブル又はリジッドフレキシブル基板である、請求項１２～１４のいずれか１項に記載の接続構造体の製造方法。 The method for manufacturing a connection structure according to any one of claims 12 to 14, wherein the second connection target member is a resin film, a flexible printed board, a flexible flat cable, or a rigid flexible board.
PCT/JP2015/083349 2014-12-04 2015-11-27 Electroconductive paste, connection structure, and method for manufacturing connection structure WO2016088664A1 (en)

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JP2019207431A (en) * 2016-07-19 2019-12-05 積水化学工業株式会社 Light control laminate and resin spacer for the same
JP2020510117A (en) * 2017-04-26 2020-04-02 ノピオン カンパニー リミテッド Method of manufacturing anisotropic conductive adhesive including gapper and method of mounting component using gapper
JP2020510741A (en) * 2017-02-06 2020-04-09 ノピオン カンパニー リミテッド Method for producing anisotropic conductive adhesive for fine pitch and anisotropic conductive adhesive for fine pitch produced by the method
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JP2020510117A (en) * 2017-04-26 2020-04-02 ノピオン カンパニー リミテッド Method of manufacturing anisotropic conductive adhesive including gapper and method of mounting component using gapper
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