JP2019160788A - Conductive material, connection structure and method for producing connection structure - Google Patents

Abstract

To provide a conductive material that allows solder to be efficiently disposed on an electrode, and can effectively improve conduction reliability between vertical electrodes to be connected.SOLUTION: A conductive material has a thermosetting component and a solder particle. An absolute difference between a solidus temperature of the solder particle and a liquidus temperature of the solder particle is 5°C or more. In the conductive material 100 wt.%, the content of the solder particles is 15 wt.% or more.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a conductive material including a thermosetting component and solder particles. The present invention also relates to a connection structure using the conductive material and a method for manufacturing the connection structure.

  Anisotropic conductive materials such as anisotropic conductive pastes and anisotropic conductive films are widely known. In the anisotropic conductive material, conductive particles are dispersed in a binder resin.

  The anisotropic conductive material is used to obtain various connection structures. Examples of the connection using the anisotropic conductive material include a connection between a flexible printed circuit board and a glass substrate (FOG (Film on Glass)), a connection between a semiconductor chip and a flexible printed circuit board (COF (Chip on Film)), and a semiconductor. Examples include connection between a 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.

  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.

  Patent Document 1 below discloses an anisotropic conductive material containing a large number of conductive particles in a thermosetting resin. The conductive particles have a solidus temperature of 125 ° C. or higher and a peak temperature of 200 ° C. or lower. The temperature difference between the solidus temperature of the conductive particles and the peak temperature of the conductive particles is 15 ° C. or more.

  Patent Document 2 below discloses a thermosetting resin composition containing solder particles, a thermosetting resin binder, and a flux component. The solder particles are composed of an alloy of Sn and a metal selected from Ag, Cu, Bi, Zn, or In. The melting point of the solder particles is 240 ° C. or less. The thermosetting resin binder includes a liquid epoxy resin and a liquid phenol resin curing agent. In the said thermosetting resin composition, content of the said solder particle is the range of 70 mass%-95 mass%. The solder particles are dispersed in the thermosetting resin composition. The said thermosetting resin composition can be apply | coated to the surface of a wiring board.

WO2008 / 111615A1 JP 2014-98168 A

  When conducting a conductive connection using a conductive material containing solder particles, the plurality of upper electrodes and the plurality of lower electrodes are electrically connected to perform conductive connection. The solder is preferably disposed between the upper and lower electrodes, and is preferably not disposed between adjacent lateral electrodes. It is desirable that the adjacent lateral electrodes are not electrically connected.

  In general, a conductive material containing solder particles is used after being placed on a substrate and then heated by reflow or the like. When the conductive material is heated to the melting point or higher of the solder particles, the solder particles are melted and the solder is aggregated between the electrodes, so that the upper and lower electrodes are electrically connected.

  In a conventional conductive material containing solder particles, when the conductive material is heated, the solder particles may melt and the fluidity of the solder may become too high. When the fluidity of the solder becomes too high, the solder aggregation rate may become too fast. In a conductive material containing conventional solder particles, the solder agglomeration rate is too fast, so that the solder remains between adjacent lateral electrodes and all the solder cannot agglomerate on the electrodes and should be connected Solder may not be efficiently arranged between the upper and lower electrodes. As a result, the amount of solder disposed between the upper and lower electrodes to be connected is reduced, the conduction reliability between the upper and lower electrodes to be connected is lowered, or the insulation reliability between adjacent lateral electrodes is reduced. May be lowered. With conventional conductive materials, it is difficult to adjust the cohesive strength of solder.

  In the anisotropic conductive material described in Patent Document 1, the content of the conductive particles is small, and it is difficult to electrically connect the electrodes.

  An object of the present invention is to provide a conductive material that can efficiently arrange solder on an electrode and can effectively improve the conduction reliability between upper and lower electrodes to be connected. Another object of the present invention is to provide a connection structure using the conductive material and a method for manufacturing the connection structure.

  According to a wide aspect of the present invention, the composition includes a thermosetting component and solder particles, and an absolute value of a difference between a solidus temperature of the solder particles and a liquidus temperature of the solder particles is 5 ° C. or more. A conductive material in which the content of the solder particles is 15% by weight or more in 100% by weight of the conductive material is provided.

  On the specific situation with the electrically-conductive material which concerns on this invention, the viscosity of the electrically-conductive material in the solidus temperature of the said solder particle is 0.1 Pa.s or more and 50 Pa.s or less.

  In a specific aspect of the conductive material according to the present invention, the solder particles include bismuth, indium, silver, copper, or tin.

  On the specific situation with the electrically-conductive material which concerns on this invention, content of bismuth is 1 to 58 weight% in 100 weight% of metals contained in the said solder particle.

  On the specific situation with the electrically-conductive material which concerns on this invention, content of an indium is 1 to 52 weight% in 100 weight% of metals contained in the said solder particle.

  On the specific situation with the electrically-conductive material which concerns on this invention, the solidus line temperature of the said solder particle is 115 degreeC or more and 220 degrees C or less.

  On the specific situation with the electrically-conductive material which concerns on this invention, the particle diameter of the said solder particle is 0.01 micrometer or more and 30 micrometers or less.

  In a specific aspect of the conductive material according to the present invention, the conductive material is a conductive paste.

  According to a wide aspect of the present invention, a first connection target member having a first electrode on the surface, a second connection target member having a second electrode on the surface, the first connection target member, A connecting portion connecting the second connection target member, wherein the material of the connecting portion is the conductive material described above, and the first electrode and the second electrode are the connecting portion. A connection structure is provided that is electrically connected by a solder portion therein.

  In a specific aspect of the connection structure according to the present invention, 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. When the portion is viewed, the solder portion in the connection portion is arranged in 50% or more of the area of 100% of the portion where the first electrode and the second electrode face each other.

  According to a wide aspect of the present invention, using the conductive material described above, the step of disposing the conductive material on the surface of the first connection target member having the first electrode on the surface; On the surface opposite to the first connection target member side, the second connection target member having the second electrode on the surface is arranged so that the first electrode and the second electrode face each other. A step of connecting the first connection target member and the second connection target member by heating the conductive material to a temperature equal to or higher than a liquidus temperature of the solder particles; And a method of electrically connecting the first electrode and the second electrode with a solder portion in the connection portion.

  In a specific aspect of the manufacturing method of the connection structure according to the present invention, the first electrode and the second electrode are stacked in the stacking direction of the first electrode, the connection portion, and the second electrode. A connection in which the solder part in the connection part is arranged in 50% or more of the area of 100% of the part where the first electrode and the second electrode face each other when the part facing each other is viewed. Get a structure.

  The conductive material according to the present invention includes a thermosetting component and solder particles. In the conductive material according to the present invention, the absolute value of the difference between the solidus temperature of the solder particles and the liquidus temperature of the solder particles is 5 ° C. or more. In the conductive material according to the present invention, the content of the solder particles is 15% by weight or more in 100% by weight of the conductive material. In the conductive material according to the present invention, since the above-described configuration is provided, the solder can be efficiently arranged on the electrode, and the conduction reliability between the upper and lower electrodes to be connected is effectively increased. Can do.

FIG. 1 is a cross-sectional view schematically showing a connection structure obtained using a conductive material according to an embodiment of the present invention. 2A to 2C are cross-sectional views for explaining each step of an example of a method for manufacturing a connection structure using a conductive material according to an embodiment of the present invention. FIG. 3 is a cross-sectional view showing a modification of the connection structure.

  Details of the present invention will be described below.

(Conductive material)
The conductive material according to the present invention includes a thermosetting component and solder particles. In the conductive material according to the present invention, the absolute value of the difference between the solidus temperature of the solder particles and the liquidus temperature of the solder particles is 5 ° C. or more. In the conductive material according to the present invention, the content of the solder particles is 15% by weight or more in 100% by weight of the conductive material.

  In the conductive material according to the present invention, since the above-described configuration is provided, the solder can be efficiently arranged on the electrode, and the conduction reliability between the upper and lower electrodes to be connected is effectively increased. Can do.

  In the conductive material according to the present invention, since the content of the solder particles in 100% by weight of the conductive material is 15% by weight or more, it is possible to agglomerate the solder on the electrode and between the upper and lower electrodes to be connected. Solder can be arranged efficiently. In the present invention, the content of the solder particles satisfying the above range is an important configuration for obtaining the effects of the present invention.

  The conductive material containing the solder particles is used after being placed on the substrate and then heated by reflow or the like. When the conductive material is heated to the melting point or higher of the solder particles, the solder particles are melted and the solder is aggregated between the electrodes, so that the upper and lower electrodes are electrically connected.

  In a conventional conductive material containing solder particles, when the conductive material is heated, the solder particles may melt and the fluidity of the solder may become too high. When the fluidity of the solder becomes too high, the solder aggregation rate may become too fast. In a conductive material containing conventional solder particles, the solder agglomeration rate is too fast, so that the solder remains between adjacent lateral electrodes and all the solder cannot agglomerate on the electrodes and should be connected Solder may not be efficiently arranged between the upper and lower electrodes.

  The inventors pay attention to the absolute value of the difference between the solidus temperature of the solder particles and the liquidus temperature of the solder particles, and by using specific solder particles, adjust the solder fluidity, It has been found that the aggregation rate can be adjusted. In the present invention, by appropriately adjusting the solder fluidity and the solder cohesive force, the solder can be efficiently arranged between the electrodes to be connected, and the conduction reliability between the upper and lower electrodes to be connected. Sexually can be enhanced effectively.

  Moreover, the solder remaining between the adjacent lateral electrodes can be reduced by appropriately adjusting the solder fluidity and the solder cohesive force. As a result, it is possible to effectively increase the insulation reliability between adjacent lateral electrodes that should not be connected.

  In the present invention, since the above-described configuration is provided, when the electrodes are electrically connected, the solder is likely to gather between the upper and lower electrodes, and the solder is disposed on the electrode (line). Can do. Further, it is difficult for a part of the solder to be disposed between the lateral electrodes that should not be connected, and the amount of solder disposed between the lateral electrodes that should not be connected can be considerably reduced. As a result, according to the present invention, it is possible to reduce the remaining amount of solder between the lateral electrodes that should not be connected.

  In the present invention, in order to obtain the above effects, it is greatly contributed that the conductive material contains specific solder particles.

  Furthermore, in the present invention, it is possible to prevent positional deviation between the electrodes. In the present invention, when the second connection target member is superimposed on the first connection target member having the conductive material disposed on the upper surface, the electrode of the first connection target member and the electrode of the second connection target member Even in a state of misalignment, the electrodes can be connected by correcting the misalignment (self-alignment effect).

  From the viewpoint of more efficiently arranging the solder on the electrode, the conductive material is preferably liquid at 25 ° C., and preferably a conductive paste. The conductive material is preferably a conductive paste at 25 ° C.

  From the viewpoint of more efficiently arranging the solder on the electrode, the viscosity (η25) at 25 ° C. of the conductive material is preferably 0.1 Pa · s or more, more preferably 30 Pa · s or more, and still more preferably. It is 50 Pa · s or more, preferably 400 Pa · s or less, more preferably 300 Pa · s or less. The said viscosity ((eta) 25) can be suitably adjusted with the kind and compounding quantity of a compounding component.

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

  The viscosity (ηsp) of the conductive material at the solidus temperature of the solder particles is preferably 0.1 Pa · s or more, more preferably 0.2 Pa · s or more, preferably 50 Pa · s or less, more preferably 10 Pa. -S or less. When the viscosity (ηsp) is not less than the above lower limit and not more than the above upper limit, the solder can be more efficiently arranged on the electrode, and the conduction reliability between the upper and lower electrodes to be connected is more effective. Can be enhanced.

  The viscosity (ηsp) of the conductive material at the solidus temperature of the solder particles is STRESSTECH (manufactured by REOLOGICA) or the like, strain control 1 rad, frequency 1 Hz, temperature rising rate 20 ° C./min, measurement temperature range 25 ° C. to Measurement is possible under the condition of 200 ° C. (however, when the solidus temperature of the solder particles exceeds 200 ° C., the upper limit of the temperature is the solidus temperature of the solder particles). From the measurement results, the viscosity of the solder particles at the solidus temperature (° C.) is evaluated.

  The viscosity (ηmp) of the conductive material at the liquidus temperature (melting point) of the solder particles 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 · s or more. When the viscosity (ηmp) is equal to or lower than the upper limit, the solder can be efficiently aggregated on the electrode. If the said viscosity is more than the said minimum, the void in a connection part can be suppressed and the protrusion of the electrically-conductive material other than a connection part can be suppressed.

  The viscosity (ηmp) is STRESSTECH (manufactured by REOLOGICA), etc., strain control 1 rad, frequency 1 Hz, temperature rising rate 20 ° C./min, measurement temperature range 25 ° C. to 200 ° C. (however, the liquidus of solder particles) When the temperature (melting point) exceeds 200 ° C., the temperature upper limit can be measured under the condition of the liquidus temperature (melting point) of the solder particles. From the measurement results, the viscosity of the solder particles at the liquidus temperature (melting point) (° C.) is evaluated.

  The conductive material can be used as a conductive paste and a conductive film. The conductive paste is preferably an anisotropic conductive paste, and the conductive film is preferably an anisotropic conductive film. From the viewpoint of more efficiently disposing the solder on the electrode, the conductive material is preferably a conductive paste. The conductive material is preferably used for electrical connection of electrodes. The conductive material is preferably a circuit connection material.

  Hereinafter, each component contained in the conductive material will be described. In the present specification, “(meth) acryl” means one or both of “acryl” and “methacryl”.

(Solder particles)
As for the said solder particle, both a center part and an outer surface are formed with the solder. The solder particles are particles in which both the central portion and the outer surface are solder. In place of the solder particles, when conductive particles including base particles formed from a material other than solder and solder portions arranged on the surface of the base particles are used, the conductive particles are conductive on the electrodes. Particles are difficult to collect. Moreover, in the said electroconductive particle, since the solder joint property of electroconductive particles is low, there exists a tendency for the electroconductive particle which moved on the electrode to move out of an electrode easily, and also has the effect of suppressing the position shift between electrodes. Tend to be lower.

  The solder is preferably a metal (low melting point metal) having a liquidus temperature (melting point) of 450 ° C. or lower. The solder particles are preferably metal particles (low melting point metal particles) having a liquidus temperature (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 liquidus temperature (melting point) of 450 ° C. or lower. The liquidus temperature (melting point) of the low melting point metal is preferably 300 ° C. or lower, more preferably 220 ° C. or lower, and further preferably 190 ° C. or lower.

  The liquidus temperature of the solder particles is preferably 140 ° C. or higher, more preferably 145 ° C. or higher, preferably 230 ° C. or lower, more preferably 225 ° C. or lower. When the liquidus temperature of the solder particles is not less than the above lower limit and not more than the above upper limit, the solder can be arranged more efficiently on the electrode, and the conduction reliability between the upper and lower electrodes to be connected is improved. It can be increased even more effectively.

  The solidus temperature of the solder particles is preferably 115 ° C. or higher, more preferably 120 ° C. or higher, preferably 220 ° C. or lower, more preferably 150 ° C. or lower, and further preferably 145 ° C. or lower. When the solidus temperature of the solder particles is not less than the above lower limit and not more than the above upper limit, the solder can be arranged more efficiently on the electrodes, and the conduction reliability between the upper and lower electrodes to be connected can be improved. It can be increased even more effectively.

  In the conductive material, the absolute value of the difference between the solidus temperature of the solder particles and the liquidus temperature of the solder particles is 5 ° C. or more. The absolute value of the difference between the solidus temperature of the solder particles and the liquidus temperature of the solder particles is preferably 5 ° C or higher, more preferably 8 ° C or higher, preferably 100 ° C or lower, more preferably 90 ° C. It is below ℃. When the absolute value of the difference between the solidus temperature of the solder particles and the liquidus temperature of the solder particles is not less than the lower limit and not more than the upper limit, the solder can be disposed more efficiently on the electrode. In addition, the conduction reliability between the upper and lower electrodes to be connected can be further effectively improved.

  The liquidus temperature of the solder particles and the solidus temperature of the solder particles can be determined by differential scanning calorimetry (DSC). The differential scanning calorimetry (DSC) is preferably measured under the conditions of temperature increase range: 30 ° C. to 500 ° C., temperature increase rate: 5 ° C./min, nitrogen purge amount: 5 ml / min. Examples of the differential scanning calorimetry (DSC) apparatus include “EXSTAR DSC7020” manufactured by SII. With respect to the obtained differential scanning calorimetry (DSC) curve, a straight line obtained by extending the base line on the low temperature side to the high temperature side is drawn, and a tangent line (tangent line 1) is drawn at the point where the slope of the curve on the low temperature side of the melting peak becomes maximum. . The temperature at the intersection of the straight line extended to the high temperature side and the tangent (tangent 1) is defined as the solidus temperature. In addition, for the obtained differential scanning calorimetry (DSC) curve, a straight line obtained by extending the base line on the high temperature side to the low temperature side is drawn, and a tangent line (tangent line 2) is obtained at the point where the slope of the curve on the high temperature side of the melting peak becomes maximum. pull. The temperature at the intersection of the straight line extended to the low temperature side and the tangent line (tangent line 2) is defined as the liquidus temperature.

  The solidus temperature of the solder particles, the liquidus temperature of the solder particles, and the absolute value of the difference between the solidus temperature of the solder particles and the liquidus temperature of the solder particles are adjusted to the preferred range. Examples of the method include a method of adjusting the type and content of the metal contained in the solder particles.

  The solder particles preferably include bismuth, indium, silver, copper, or tin, more preferably include bismuth, indium, or tin, and further preferably include bismuth or indium. When the solder particles satisfy the above-described preferred embodiment, the solder can be arranged more efficiently on the electrodes, and the conduction reliability between the upper and lower electrodes to be connected can be further effectively improved. it can.

  The content of tin in 100% by weight of the metal contained in the solder particles is preferably 30% by weight or more, more preferably 40% by weight or more, preferably 90% by weight or less, more preferably 70% by weight or less. is there. When the content of tin in the solder particles is not less than the above lower limit and not more than the above upper limit, conduction reliability and connection reliability between the solder portion and the electrode are further enhanced.

  In 100% by weight of the metal contained in the solder particles, the content of bismuth is preferably 1% by weight or more, more preferably 2% by weight or more, preferably 58% by weight or less, more preferably 55% by weight or less. is there. When the content of bismuth in the solder particles is not less than the above lower limit and not more than the above upper limit, the solder can be arranged more efficiently on the electrode, and the conduction reliability between the upper and lower electrodes to be connected is improved. It can be increased even more effectively.

  The content of indium in 100% by weight of the metal contained in the solder particles is preferably 1% by weight or more, more preferably 2% by weight or more, preferably 52% by weight or less, more preferably 45% by weight or less. is there. When the content of indium in the solder particles is not less than the above lower limit and not more than the above upper limit, the solder can be arranged more efficiently on the electrode, and the conduction reliability between the upper and lower electrodes to be connected can be improved. It can be increased even more effectively.

  The content of tin, bismuth, or indium is 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). ) And the like.

  By using the 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. Moreover, as a result of the use of the solder particles, the bonding strength between the solder part and the electrode is increased. As a result, peeling between the solder part and the electrode is less likely to occur, and the conduction reliability and the connection reliability are further improved.

  The 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, a tin-silver alloy, a tin-silver-copper alloy, a tin-bismuth alloy, or a tin-indium alloy because of its excellent wettability with respect to the electrode. The low melting point metal is more preferably a tin-bismuth alloy or 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. Examples of the composition of the solder particles include a metal composition containing zinc, gold, silver, lead, copper, tin, bismuth, indium, and the like. The solder particles preferably do not contain lead, and preferably contain tin and indium, or contain tin and bismuth. The solder particles may contain a eutectic solder. When the solder particles include eutectic solder, it is preferable to mix a plurality of solder particles so that the absolute value of the difference between the solidus temperature and the liquidus temperature is 5 ° C. or higher.

  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, Metals such as molybdenum and palladium may be included. 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 100 wt% of the metal contained in the solder particles, preferably 0.0001 wt% or more, Preferably it is 1 weight% or less.

  The particle size of the solder particles is preferably 0.01 μm or more, more preferably 1 μm or more, further preferably 2 μm or more, particularly preferably 3 μm or more, preferably 30 μm or less, more preferably 20 μm or less, and even more preferably 10 μm. It is as follows. When the particle diameter of the solder particles is not less than the above lower limit and not more than the above upper limit, the solder can be more efficiently disposed on the electrode. The particle diameter of the solder particles is particularly preferably 3 μm or more and 10 μm or less.

  The particle diameter of the solder particles is preferably an average particle diameter, and more preferably a number average particle diameter. The particle size of the solder particles is, for example, observing 50 arbitrary solder particles with an electron microscope or an optical microscope, calculating an average value of the particle size of each solder particle, or performing a laser diffraction particle size distribution measurement. Is required. In observation with an electron microscope or an optical microscope, the particle diameter of one solder particle is determined as a particle diameter in a circle-equivalent diameter. In observation with an electron microscope or an optical microscope, the average particle diameter at an equivalent circle diameter of any 50 solder particles is substantially equal to the average particle diameter at a sphere equivalent diameter. In the laser diffraction particle size distribution measurement, the particle diameter of one solder particle is obtained as a particle diameter in a sphere equivalent diameter. The average particle size of the solder particles is preferably calculated by laser diffraction particle size distribution measurement.

  The coefficient of variation (CV value) of the solder particle diameter is preferably 5% or more, more preferably 10% or more, preferably 40% or less, more preferably 30% or less. When the coefficient of variation of the particle diameter of the solder particles is not less than the above lower limit and not more than the above upper limit, the solder can be more efficiently arranged on the electrode. However, the CV value of the particle diameter of the solder particles may be less than 5%.

  The coefficient of variation (CV value) can be measured as follows.

CV value (%) = (ρ / Dn) × 100
ρ: 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.

  In the conductive material, the content of the solder particles is 15% by weight or more in 100% by weight of the conductive material. In 100% by weight of the conductive material, the content of the solder particles is preferably 20% by weight or more, more preferably 30% by weight or more, further preferably 40% by weight or more, preferably 90% by weight or less, more preferably It is 85 wt% or less, more preferably 80 wt% 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 on the electrodes, and it is easy to dispose a lot of solder between the electrodes. Reliability becomes even higher. From the viewpoint of further improving the conduction reliability, it is preferable that the content of the solder particles is large.

(Thermosetting component)
The conductive material includes a thermosetting component. The conductive material may contain a thermosetting compound and a thermosetting agent as a thermosetting component. In order to increase the degree of curing of the conductive material, the conductive material preferably includes a thermosetting compound and a thermosetting agent as the thermosetting component. In order to increase the degree of curing of the conductive material, the conductive material preferably includes a curing accelerator as a thermosetting component.

(Thermosetting component: thermosetting compound)
The thermosetting compound is not particularly limited. 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 material, from the viewpoint of more effectively increasing the conduction reliability, and from the viewpoint of further increasing the insulation reliability more effectively, as the thermosetting compound, Epoxy compounds or episulfide compounds are preferred, and epoxy compounds are more preferred. The thermosetting compound preferably contains an epoxy compound. As for the said thermosetting compound, only 1 type may be used and 2 or more types may be used together.

  The epoxy compound is a compound having at least one epoxy group. Examples of the epoxy compounds include bisphenol A type epoxy compounds, bisphenol F type epoxy compounds, bisphenol S type epoxy compounds, phenol novolac type epoxy compounds, biphenyl type epoxy compounds, biphenyl novolac type epoxy compounds, biphenol type epoxy compounds, and naphthalene type epoxy compounds. Fluorene type epoxy compound, phenol aralkyl type epoxy compound, naphthol aralkyl type epoxy compound, dicyclopentadiene type epoxy compound, anthracene type epoxy compound, epoxy compound having adamantane skeleton, epoxy compound having tricyclodecane skeleton, naphthylene ether type Examples thereof include an epoxy compound and an epoxy compound having a triazine nucleus in the skeleton. As for the said epoxy compound, only 1 type may be used and 2 or more types may be used together.

  The epoxy compound is liquid or solid at normal temperature (23 ° C.), and when the epoxy compound is solid at normal temperature, the melting temperature of the epoxy compound is not higher than the liquidus temperature of the solder particles. Is preferred. By using the above-mentioned preferable epoxy compound, the first connection target member and the second connection are high when the connection target member is pasted and when the viscosity is high and acceleration is applied by impact such as conveyance. The positional deviation with respect to the target member can be suppressed. Furthermore, the viscosity of the conductive material can be greatly reduced by heat at the time of curing, and the solder can be efficiently aggregated.

  From the viewpoint of further increasing the insulation reliability more effectively and from the viewpoint of increasing the conduction reliability more effectively, the thermosetting compound preferably contains an epoxy compound.

  From the viewpoint of more effectively disposing the solder on the electrode, the thermosetting compound preferably includes a thermosetting compound having a polyether skeleton.

  Examples of the thermosetting compound having a polyether skeleton include a compound having a glycidyl ether group at both ends of an alkyl chain having 3 to 12 carbon atoms, and a polyether skeleton having 2 to 4 carbon atoms. Examples thereof include polyether type epoxy compounds having structural units in which 2 to 10 are bonded continuously.

  From the viewpoint of further effectively increasing the heat resistance of the cured product, the thermosetting compound preferably includes a thermosetting compound having an isocyanuric skeleton.

  Examples of the thermosetting compound having the above isocyanuric skeleton include triisocyanurate type epoxy compounds, etc., and TEPIC series (TEPIC-G, TEPIC-S, TEPIC-SS, TEPIC-HP, TEPIC-L, manufactured by Nissan Chemical Industries, Ltd.) TEPIC-PAS, TEPIC-VL, TEPIC-UC) and the like.

  In 100% by weight of the conductive material, the content of the thermosetting compound is preferably 5% by weight or more, more preferably 10% by weight or more, preferably 85% by weight or less, more preferably 75% by weight or less, Preferably it is 65 weight% or less, Most preferably, it is 55 weight% or less. When the content of the thermosetting compound is not less than the above lower limit and not more than the above upper limit, the solder can be disposed more efficiently on the electrodes, and the insulation reliability between the electrodes can be further effectively improved. Further, the conduction reliability between the electrodes can be further effectively improved. From the viewpoint of more effectively increasing the impact resistance, it is preferable that the content of the thermosetting compound is large.

  In 100% by weight of the conductive material, the content of the epoxy compound is preferably 5% by weight or more, more preferably 10% by weight or more, preferably 85% by weight or less, more preferably 75% by weight or less, and still more preferably. It is 65% by weight or less, particularly preferably 55% by weight or less. When the content of the epoxy compound is not less than the above lower limit and not more than the above upper limit, the solder can be more efficiently arranged on the electrodes, and the insulation reliability between the electrodes can be further effectively improved, The conduction reliability between them can be further effectively improved. From the viewpoint of further improving the impact resistance, it is preferable that the content of the epoxy compound is large.

(Thermosetting component: thermosetting agent)
The said thermosetting agent is not specifically limited. 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 anhydride curing agents, thermal cation initiators (thermal cation curing agents), and thermal radical generators. Is mentioned. As for the said thermosetting agent, only 1 type may be used and 2 or more types may be used together.

  From the viewpoint of allowing the conductive material to be cured more rapidly at a low temperature, the thermosetting agent is preferably an imidazole curing agent, a thiol curing agent, or an amine curing agent. Further, from the viewpoint of enhancing the storage stability when the thermosetting compound and the thermosetting agent are mixed, the thermosetting agent is preferably a latent curing agent. 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.

  The imidazole curing agent is not particularly limited. Examples of the imidazole curing agent include 2-methylimidazole, 2-ethyl-4-methylimidazole, 1-cyanoethyl-2-phenylimidazole, 1-cyanoethyl-2-phenylimidazolium trimellitate, 2,4-diamino-6. -[2'-methylimidazolyl- (1 ')]-ethyl-s-triazine and 2,4-diamino-6- [2'-methylimidazolyl- (1')]-ethyl-s-triazine isocyanuric acid adducts 2-phenyl-4,5-dihydroxymethylimidazole, 2-phenyl-4-methyl-5-hydroxymethylimidazole, 2-phenyl-4-benzyl-5-hydroxymethylimidazole, 2-paratoluyl-4-methyl-5 -Hydroxymethylimidazole, 2-metatoluyl-4-methyl-5- Roxymethylimidazole, 2-metatoluyl-4,5-dihydroxymethylimidazole, 2-paratoluyl-4,5-dihydroxymethylimidazole, etc., the hydrogen at the 5-position of 1H-imidazole is a hydroxymethyl group and the hydrogen at the 2-position Examples thereof include an imidazole compound substituted with a phenyl group or a toluyl group.

  The thiol curing agent is not particularly limited. Examples of the thiol curing agent include trimethylolpropane tris-3-mercaptopropionate, pentaerythritol tetrakis-3-mercaptopropionate, and dipentaerythritol hexa-3-mercaptopropionate.

  The amine curing agent is not particularly limited. Examples of the amine curing agent include hexamethylenediamine, octamethylenediamine, decamethylenediamine, 3,9-bis (3-aminopropyl) -2,4,8,10-tetraspiro [5.5] undecane, bis (4 -Aminocyclohexyl) methane, metaphenylenediamine, diaminodiphenylsulfone and the like.

  The acid anhydride curing agent is not particularly limited and can be widely used as long as it is an acid anhydride used as a curing agent for a thermosetting compound such as an epoxy compound. Examples of the acid anhydride curing agent include phthalic anhydride, tetrahydrophthalic anhydride, trialkyltetrahydrophthalic anhydride, hexahydrophthalic anhydride, methylhexahydrophthalic anhydride, methyltetrahydrophthalic anhydride, methylbutenyltetrahydrophthalic anhydride. Phthalic acid anhydride, maleic anhydride, nadic anhydride, methyl nadic anhydride, glutaric anhydride, succinic anhydride, glycerin bistrimellitic anhydride monoacetate, and ethylene glycol bistrimellitic anhydride Acid anhydride curing agent, trifunctional acid anhydride curing agent such as trimellitic anhydride, pyromellitic anhydride, benzophenone tetracarboxylic anhydride, methylcyclohexene tetracarboxylic acid anhydride, polyazeline acid anhydride, etc. 4 or more functional acid anhydrides Curing agents.

  The thermal cation initiator is not particularly limited. 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.

  The thermal radical generator is not particularly limited. Examples of the thermal radical generator 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, further preferably 80 ° C. or higher, preferably 250 ° C. or lower, more preferably 200 ° C. or lower, and further preferably 150 ° C. Hereinafter, it is particularly preferably 140 ° C. or lower. 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 is more efficiently disposed on the electrode. The reaction start temperature of the thermosetting agent is particularly preferably 80 ° C. or higher and 140 ° C. or lower.

  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 liquidus temperature of the solder particles, more preferably 5 ° C. or more. More preferably, it is 10 ° C. or higher.

  The reaction start temperature of the thermosetting agent means a 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 with respect to 100 parts by weight of the thermosetting compound 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 or less, more preferably 75 parts by weight or less. When the content of the thermosetting agent is not less than the above lower limit, it is easy to sufficiently cure the conductive material. 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.

(Thermosetting component: curing accelerator)
The conductive material may contain a curing accelerator. The said hardening accelerator is not specifically limited. The curing accelerator preferably acts as a curing catalyst in the reaction between the thermosetting compound and the thermosetting agent. The curing accelerator preferably acts as a curing catalyst in the reaction with the thermosetting compound. As for the said hardening accelerator, only 1 type may be used and 2 or more types may be used together.

  Examples of the curing accelerator include phosphonium salts, tertiary amines, tertiary amine salts, quaternary onium salts, tertiary phosphines, crown ether complexes, and phosphonium ylides. Specifically, the curing accelerators include imidazole compounds, isocyanurates of imidazole compounds, dicyandiamide, dicyandiamide derivatives, melamine compounds, melamine compound derivatives, diaminomaleonitrile, diethylenetriamine, triethylenetetramine, tetraethylenepentamine. , Amine compounds such as bis (hexamethylene) triamine, triethanolamine, diaminodiphenylmethane, organic acid dihydrazide, 1,8-diazabicyclo [5,4,0] undecene-7, 3,9-bis (3-aminopropyl) -2,4,8,10-tetraoxaspiro [5,5] undecane, boron trifluoride, and triphenylphosphine, tricyclohexylphosphine, tributylphosphine and methyldiphenylphosphine And the like organic phosphorus compounds.

  The phosphonium salt is not particularly limited. Examples of the phosphonium salts include tetranormal butylphosphonium bromide, tetranormal butylphosphonium O, O-diethyldithiophosphoric acid, methyltributylphosphonium dimethyl phosphate, tetranormal butylphosphonium benzotriazole, tetranormal butylphosphonium tetrafluoroborate, and tetranormal borates. And butylphosphonium tetraphenylborate.

  The content of the curing accelerator is appropriately selected so that the thermosetting compound is cured well. The content of the curing accelerator with respect to 100 parts by weight of the thermosetting compound is preferably 0.5 parts by weight or more, more preferably 0.8 parts by weight or more, preferably 10 parts by weight or less, more preferably 8 parts by weight. Less than parts by weight. When the content of the curing accelerator is not less than the above lower limit and not more than the above upper limit, the thermosetting compound can be cured well.

(flux)
The conductive material may contain a flux. By using the flux, the solder can be arranged more efficiently on the electrode. The flux is not particularly limited. As said flux, the flux generally used for soldering etc. 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 amine compound, an organic acid, and Examples include pine resin. 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 or 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.

  Examples of the organic acid having two or more carboxyl groups include succinic acid, glutaric acid, adipic acid, pimelic acid, suberic acid, azelaic acid, and sebacic acid.

  Examples of the amine compound include cyclohexylamine, dicyclohexylamine, benzylamine, benzhydrylamine, imidazole, benzimidazole, phenylimidazole, carboxybenzimidazole, benzotriazole, and carboxybenzotriazole.

  The rosin is a rosin composed mainly of abietic acid. Examples of the rosins include abietic acid and acrylic modified rosin. The flux is preferably a rosin, 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, and still more preferably 160 ° C or lower, more preferably 150 ° C or lower, still more preferably 140 ° C or lower. 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 is more efficiently arranged on the electrode. The active temperature (melting point) of the flux is preferably 80 ° C. or higher and 190 ° C. or lower. The activation temperature (melting point) of the flux is particularly preferably 80 ° C. or higher and 140 ° C. or lower.

  Examples of the flux having an active temperature (melting point) of 80 to 190 ° C. include succinic acid (melting point 186 ° C.), glutaric acid (melting point 96 ° C.), adipic acid (melting point 152 ° C.), pimelic acid (melting point 104 And dicarboxylic acids such as suberic acid (melting point 142 ° C.), benzoic acid (melting point 122 ° C.), malic acid (melting point 130 ° C.), and the like.

  The boiling point of the flux is preferably 200 ° C. or lower.

  From the viewpoint of more efficiently arranging the solder on the electrode, the melting point of the flux is preferably higher than the liquidus temperature of the solder particles, more preferably 5 ° C or higher, more preferably 10 ° C or higher. More preferably, it is high.

  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, it is high.

  The flux may be dispersed in the conductive material or may be attached on the surface of the solder particles.

  Since the melting point of the flux is higher than the liquidus temperature of the solder particles, the solder 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. When the temperature exceeds the liquidus temperature of the solder particles, 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 that have moved preferentially to the electrode is removed, and the solder wets on the surface of the electrode. Can be expanded. Thereby, a solder can be efficiently aggregated on an electrode.

  The flux is preferably a flux that releases cations by heating. By using a flux that releases cations by heating, the solder can be arranged more efficiently on the electrode.

  Examples of the flux that releases cations by the heating include the thermal cation initiator (thermal cation curing agent).

  From the viewpoint of more efficiently arranging the solder on the electrode, the viewpoint of increasing the insulation reliability more effectively, and the viewpoint of improving the conduction reliability more effectively, the above flux is composed of an acid compound and a base compound. And a salt thereof.

  The acid compound is preferably an organic compound having a carboxyl group. Examples of the acid compound include aliphatic carboxylic acids such as malonic acid, succinic acid, glutaric acid, adipic acid, pimelic acid, suberic acid, azelaic acid, sebacic acid, citric acid, malic acid, and cyclic aliphatic carboxylic acid. Examples thereof include cyclohexyl carboxylic acid, 1,4-cyclohexyl dicarboxylic acid, aromatic carboxylic acid such as isophthalic acid, terephthalic acid, trimellitic acid, and ethylenediaminetetraacetic acid. From the viewpoint of more efficiently arranging the solder on the electrode, the viewpoint of increasing the insulation reliability more effectively, and the viewpoint of further improving the conduction reliability more effectively, the acid compound is glutaric acid, cyclohexyl. Carboxylic acid or adipic acid is preferred.

  The base compound is preferably an organic compound having an amino group. Examples of the base compound include diethanolamine, triethanolamine, methyldiethanolamine, ethyldiethanolamine, cyclohexylamine, dicyclohexylamine, benzylamine, benzhydrylamine, 2-methylbenzylamine, 3-methylbenzylamine, 4-tert-butylbenzylamine. N-methylbenzylamine, N-ethylbenzylamine, N-phenylbenzylamine, N-tert-butylbenzylamine, N-isopropylbenzylamine, N, N-dimethylbenzylamine, imidazole compounds, and triazole compounds. . From the viewpoint of more efficiently arranging the solder on the electrode, the viewpoint of increasing the insulation reliability more effectively, and the viewpoint of further improving the conduction reliability more effectively, the base compound is benzylamine. It is preferable.

  The content of the flux in 100% by weight of the conductive material is preferably 0.5% by weight or more, preferably 30% by weight or less, more preferably 25% by weight or less. The conductive material may not contain flux. When the content of the flux is not less than the above lower limit and not more than the above upper limit, it is more difficult to form an oxide film on the surface of the solder and the electrode, and further, the oxide film formed on the surface of the solder and the electrode is further increased. Can be effectively removed.

(Filler)
The conductive material according to the present invention may contain a filler. The filler may be an organic filler or an inorganic filler. When the conductive material contains a filler, the solder can be uniformly aggregated over all the electrodes of the substrate.

  It is preferable that the conductive material does not contain the filler or contains the filler at 5% by weight or less. When the thermosetting compound is used, the smaller the filler content, the easier the solder moves on the electrode.

  The content of the filler in 100% by weight of the conductive material is preferably 0% by weight (not contained) or more, preferably 5% by weight or less, more preferably 2% by weight or less, and further preferably 1% by weight or less. is there. When the content of the filler is not less than the above lower limit and not more than the above upper limit, the solder is more uniformly arranged on the electrode.

(Other ingredients)
The conductive material may be, for example, a filler, an extender, a softener, a plasticizer, a thixotropic agent, a leveling agent, a polymerization catalyst, a curing catalyst, a colorant, an antioxidant, a heat stabilizer, and a light stabilizer. In addition, various additives such as ultraviolet absorbers, lubricants, antistatic agents and flame retardants may be contained.

(Connection structure and method of manufacturing connection structure)
The connection structure according to the present invention includes a first connection target member having a first electrode on the surface, a second connection target member having a second electrode on the surface, the first connection target member, A connecting portion connecting the second connection target member. In the connection structure according to the present invention, the material of the connection portion is the conductive material 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.

  The manufacturing method of the connection structure which concerns on this invention comprises the process of arrange | positioning the said electrically-conductive material on the surface of the 1st connection object member which has a 1st electrode on the surface using the electrically conductive material mentioned above. In the method for manufacturing a connection structure according to the present invention, a second connection target member having a second electrode on a surface thereof is provided on the surface opposite to the first connection target member side of the conductive material. A step of disposing the first electrode and the second electrode so as to face each other. The manufacturing method of the connection structure according to the present invention connects the first connection target member and the second connection target member by heating the conductive material to a temperature higher than the liquidus temperature of the solder particles. A connecting portion formed of the conductive material, and electrically connecting the first electrode and the second electrode with a solder portion in the connecting portion.

  In the connection structure and the manufacturing method of the connection structure according to the present invention, since a specific conductive material is used, the solder is likely to gather between the first electrode and the second electrode, and the solder is an electrode (line). Can be efficiently placed on top. In addition, a part of the solder is difficult to be disposed in a region (space) where no electrode is formed, and the amount of solder 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.

  Moreover, in order to dispose the solder efficiently on the electrode and to considerably reduce the amount of the solder disposed in the region where the electrode is not formed, the conductive material is not a conductive film but a conductive paste. It is preferable.

  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 70% or more, and preferably 100% or less.

  In 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 second connection is applied to the conductive material. The weight of the target member is preferably added. In the method for manufacturing a connection structure according to the present invention, in the step of disposing the second connection target member and the step of forming the connection portion, the conductive material has a weight force of the second connection target member. It is preferable not to apply a pressure higher than. 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, so that a large amount of solder is easily collected between the electrodes, and the solder can be arranged more efficiently on the electrodes (lines). Further, a part of the solder is difficult to be disposed in a region (space) where no electrode is formed, and the amount of solder disposed 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.

  Moreover, if a conductive paste is used instead of a conductive film, it becomes easy to adjust the thickness 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. Moreover, in the conductive film, compared with the conductive paste, the melt viscosity of the conductive film cannot be sufficiently lowered at the melting temperature of the solder, and the aggregation of the solder tends to be hindered.

  Hereinafter, specific embodiments of the present invention will be described with reference to the drawings.

  FIG. 1 is a cross-sectional view schematically showing a connection structure obtained using a conductive material according to an embodiment of the present invention.

  The connection structure 1 shown in FIG. 1 is 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 part 4 is formed of the conductive material described above. In the present embodiment, the conductive material includes a thermosetting component and solder particles. The thermosetting component includes a thermosetting compound and a thermosetting agent. In the present embodiment, a conductive paste is used as the conductive material.

  The connection portion 4 includes a solder portion 4A in which a plurality of solder particles are gathered and joined to each other, and a cured product portion 4B in which a thermosetting compound is thermally cured.

  The first connection target 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.

  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. This also increases the conduction reliability and connection reliability in the connection structure 1. In addition, when a flux is contained in the conductive material, the flux is generally gradually deactivated by heating.

  In addition, in the connection structure 1 shown in FIG. 1, all the solder parts 4A are located in the area | region which the 1st, 2nd electrodes 2a and 3a oppose. 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 part 4X has the solder part 4XA and the hardened | cured material part 4XB. 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.

  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.

  In connection structure 1, 1X, when the part which 1st electrode 2a and 2nd electrode 3a oppose in the lamination direction of 1st electrode 2a, connection part 4, 4X, and 2nd electrode 3a is seen In addition, it is preferable that the solder portions 4A and 4XA in the connection portions 4 and 4X are arranged in 50% or more of the area of 100% of the facing portion between the first electrode 2a and the second electrode 3a. . When the solder portions 4A and 4XA in the connection portions 4 and 4X satisfy the above-described preferable mode, the conduction reliability can be further improved.

  When 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, the first electrode and the second electrode It is preferable that the solder portion in the connecting portion is arranged in 50% or more of the area of 100% of the portion facing the two electrodes. When 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, the first electrode and the second electrode It is more preferable that the solder portion in the connection portion is disposed in 60% or more of 100% of the area of the portion facing the two electrodes. When 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, the first electrode and the second electrode More preferably, the solder portion in the connecting portion is arranged in 70% or more of the area of 100% of the portion facing the two electrodes. When 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, the first electrode and the second electrode It is particularly preferable that the solder portion in the connecting portion is disposed in 80% or more of 100% of the area facing the two electrodes. When 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, the first electrode and the second electrode It is most preferable that the solder portion in the connection portion is disposed in 90% or more of the area of 100% of the portion facing the two electrodes. When the solder part in the connection part satisfies the above-described preferable aspect, the conduction reliability can be further improved.

  When the portion where the first electrode and the second electrode face each other in the direction orthogonal to the stacking direction of the first electrode, the connection portion, and the second electrode is seen, It is preferable that 60% or more of the solder portion in the connection portion is disposed in a portion where the electrode and the second electrode face each other. When the portion where the first electrode and the second electrode face each other in the direction orthogonal to the stacking direction of the first electrode, the connection portion, and the second electrode is seen, More preferably, 70% or more of the solder portion in the connection portion is disposed in a portion where the electrode and the second electrode face each other. When the portion where the first electrode and the second electrode face each other in the direction orthogonal to the stacking direction of the first electrode, the connection portion, and the second electrode is seen, More preferably, 90% or more of the solder portion in the connection portion is disposed in a portion where the electrode and the second electrode face each other. When the portion where the first electrode and the second electrode face each other in the direction orthogonal to the stacking direction of the first electrode, the connection portion, and the second electrode is seen, It is particularly preferable that 95% or more of the solder portion in the connection portion is disposed at a portion where the electrode and the second electrode face each other. When the portion where the first electrode and the second electrode face each other in the direction orthogonal to the stacking direction of the first electrode, the connection portion, and the second electrode is seen, It is most preferable that 99% or more of the solder portion in the connection portion is disposed in a portion where the electrode and the second electrode face each other. When the solder part in the connection part satisfies the above-described preferable aspect, the conduction reliability can be further improved.

  Next, FIG. 2 illustrates an example of a method for manufacturing the connection structure 1 using the conductive material according to the embodiment of the present invention.

  First, the 1st connection object member 2 which has the 1st electrode 2a on the surface (upper surface) is prepared. Next, as shown in FIG. 2A, a conductive material 11 including a thermosetting component 11B and solder particles 11A is disposed on the surface of the first connection target member 2 (first step). . The used conductive material 11 contains a thermosetting compound and a thermosetting agent as the thermosetting component 11B.

  The conductive material 11 is disposed on the surface of the first connection target member 2 on which the first electrode 2a is provided. After the conductive material 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.

  The arrangement method of the conductive material 11 is not particularly limited, and examples thereof include application using a dispenser, screen printing, and ejection using an inkjet apparatus.

  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 material 11 on the surface of the first connection target member 2, on the surface opposite to the first connection target member 2 side of the conductive material 11, The 2nd connection object member 3 is arrange | positioned (2nd process). On the surface of the conductive material 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.

  Next, the conductive material 11 is heated above the melting point of the solder particles 11A (third step). Preferably, the conductive material 11 is heated above the curing temperature of the thermosetting component 11B (thermosetting compound). 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). When the conductive paste is used instead of the conductive film, the solder particles 11A are more effectively collected between the first electrode 2a and the second electrode 3a. 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 that connects the first connection target member 2 and the second connection target member 3 is formed of the conductive material 11. The connection part 4 is formed of the conductive material 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.

  In the present embodiment, it is preferable that no pressure is applied in the second step and the third step. In this case, the weight of the second connection target member 3 is added to the conductive material 11. For this reason, the solder particles 11A are more effectively collected between the first electrode 2a and the second electrode 3a when the connection portion 4 is formed. In addition, if pressure is applied in at least one of the second step and the third step, the solder particles 11A tend to collect between the first electrode 2a and the second electrode 3a. The tendency to be inhibited becomes high.

  Moreover, in this embodiment, since pressurization is not performed, the first connection target member 2 and the second connection target member 3 are in a state where the alignment between the first electrode 2a and the second electrode 3a is shifted. Can be corrected, the first electrode 2a and the second electrode 3a can be connected (self-alignment effect). This is because the molten solder self-aggregating between the first electrode 2a and the second electrode 3a is different from the solder between the first electrode 2a and the second electrode 3a and other conductive materials. This is because, when the area in contact with the component is minimized, the energy becomes more stable, and thus the force for forming the aligned connection structure, which is the connection structure having the minimum area, acts. At this time, it is desirable that the conductive material is not cured and that the viscosity of components other than the solder particles of the conductive material is sufficiently low at that temperature and time.

  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 1st connection object member 2, the electrically-conductive material 11, and the 2nd connection object member 3 which are obtained is moved to a heating part, and the said 3rd connection object is carried out. 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.

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

  As a heating method in the third step, the entire connection structure is heated using a reflow furnace or an oven above the liquidus temperature (melting point) of the solder particles and above the curing temperature of the thermosetting component. And a method of locally heating only the connection part of the connection structure.

  As a tool used for the method of heating locally, a hot plate, a heat gun for applying hot air, a soldering iron, an infrared heater, and the like can be given.

  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.

  The said 1st, 2nd connection object member is not specifically 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 thereof include electronic components such as circuit boards such as flat cables, rigid flexible boards, glass epoxy boards, and glass boards. The first and second connection target members are preferably electronic components.

  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 not to gather on an electrode. On the other hand, by using a conductive paste, even if a resin film, a flexible printed circuit board, a flexible flat cable, or a rigid flexible circuit board is used, the conductive reliability between the electrodes can be efficiently collected by collecting the solder on the electrodes. Can be increased sufficiently. When using a resin film, a flexible printed circuit board, a flexible flat cable, or a rigid flexible circuit board, compared to the case of using other connection target members such as a semiconductor chip, the conduction reliability between the electrodes by not applying pressure is improved. The improvement effect can be obtained more effectively.

  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.

  In the connection structure according to the present invention, it is preferable that the first electrode and the second electrode are arranged in an area array or a peripheral. In the case where 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. The area array is a structure in which electrodes are arranged in a grid pattern on the surface on which 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 may be aggregated along the direction perpendicular to the comb, whereas in the area array or the peripheral structure, the electrode is disposed on the entire surface. It is necessary that the solder agglomerates uniformly. Therefore, in the conventional method, the amount of solder tends to be non-uniform, whereas in the method of the present invention, the effect of the present invention is more effectively exhibited.

  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.

Thermosetting component (thermosetting compound):
Thermosetting compound 1: Bisphenol F type epoxy compound, “YDF-8170C” manufactured by Nippon Steel & Sumikin Chemical Co., Ltd.
Thermosetting compound 2: bisphenol A type epoxy compound, “YD-8125” manufactured by Nippon Steel & Sumikin Chemical Co., Ltd.
Thermosetting compound 3: phenol novolac type epoxy compound, “DEN431” manufactured by DOW
Thermosetting compound 4: Aliphatic epoxy compound, “Epolite 1600” manufactured by Kyoeisha Chemical Co., Ltd.
Thermosetting compound 5: epoxy compound containing isocyanuric skeleton, “TEPIC-SP” manufactured by Nissan Chemical Co., Ltd.

Thermosetting component (thermosetting agent):
Thermosetting agent 1: Acid anhydride curing agent, “Ricacid TH” manufactured by Shin Nippon Chemical Co., Ltd.
Thermosetting agent 2: Acid anhydride curing agent, “Ricacid MH” manufactured by Shin Nippon Chemical Co., Ltd.

Thermosetting component (curing accelerator):
Curing accelerator 1: Organic phosphonium salt, “PX-4MP” manufactured by Nippon Chemical Industry Co., Ltd.

flux:
Flux 1: “Benzylamine glutarate”, melting point 108 ° C.
Preparation method of flux 1:
In a glass bottle, 24 g of water as a reaction solvent and 13.212 g of glutaric acid (manufactured by Wako Pure Chemical Industries, Ltd.) were added and dissolved at room temperature until uniform. Thereafter, 10.715 g of benzylamine (manufactured by Wako Pure Chemical Industries, Ltd.) was added and stirred for about 5 minutes to obtain a mixed solution. The resulting mixture was placed in a refrigerator at 5 ° C. to 10 ° C. and left overnight. The precipitated crystals were collected by filtration, washed with water, and vacuum-dried to obtain flux 1.

Solder particles:
Solder particles 1: Sn42Bi58 solder particles, average particle size 10 μm
Solder particles 2: Sn66Bi34 solder particles, average particle size 10 μm
Solder particles 3: Sn53Bi47 solder particles, average particle size 10 μm
Solder particles 4: Sn90In10 solder particles, average particle diameter 10 μm
Solder particles 5: SnIn8Ag3.5 solder particles, average particle diameter 10 μm
Solder particles 6: SnAg3Cu0.5 solder particles, average particle size 10 μm

(Examples 1-24 and Comparative Examples 1-12)
(1) Preparation of conductive material (anisotropic conductive paste) The components shown in Tables 1 to 3 below are blended in the blending amounts shown in Tables 1 to 3 to obtain conductive materials (anisotropic conductive paste). It was.

(2) Production of connection structure As a first connection target member, a glass epoxy substrate (material: FR−) having a copper electrode (electrode length: 3 mm, electrode thickness: 12 μm) of L / S = 50 μm / 50 μm on the surface. 4, thickness: 0.6 mm).

  As a second connection target member, a flexible printed circuit board (material: polyimide, thickness: 0.1 mm) having a copper electrode (electrode length: 3 mm, electrode thickness: 12 μm) of L / S = 50 μm / 50 μm is prepared. did.

  A conductive material (anisotropic conductive paste) immediately after fabrication was applied to the upper surface of the glass epoxy substrate so as to have a thickness of 100 μm, thereby forming a conductive material (anisotropic conductive paste) layer. Next, a flexible printed circuit board was laminated on the upper surface of the conductive material (anisotropic conductive paste) layer so that the electrodes face each other. The weight of the flexible printed circuit board is added to the conductive material (anisotropic conductive paste) layer. From this state, heating was performed so that the temperature of the conductive material (anisotropic conductive paste) layer became the solidus temperature of the solder particles 5 seconds after the start of temperature increase. Further, 15 seconds after the start of temperature increase, the conductive material (anisotropic conductive paste) layer is heated so that the temperature becomes 200 ° C., the conductive material (anisotropic conductive paste) layer is cured, and the connection structure is Obtained. No pressure was applied during heating.

(Evaluation)
(1) Solidus temperature of solder particles, liquidus temperature of solder particles, and absolute value of difference between solidus temperature of solder particles and liquidus temperature of solder particles Solidus temperature of solder particles and solder The liquidus temperature of the particles was measured using differential scanning calorimetry (DSC) as follows. As a differential scanning calorimetry (DSC) apparatus, “EXSTAR DSC7020” manufactured by SII was used.

(Measurement method of solidus temperature of solder particles and liquidus temperature of solder particles)
About 10 mg of the solder particles were weighed, and a sample was placed at a substantially central portion of an aluminum container (sample container), and the aluminum lid of the container was placed and clamped. The obtained sample container was attached to one container holder of a differential scanning calorimetry (DSC) apparatus. The other container holder was equipped with an empty container in which an aluminum lid was clamped without putting a sample in an aluminum container (sample container). The nitrogen gas flow rate was set to an appropriate value in the range of 10 ml / min to 50 ml / min, and was allowed to flow until the measurement was completed. The heating rate was 10 ° C./min, and the measurement was performed while heating to a temperature about 30 ° C. higher than the end of the melting peak. With respect to the obtained differential scanning calorimetry (DSC) curve, a straight line obtained by extending the base line on the low temperature side to the high temperature side is drawn, and a tangent line (tangent line 1) is drawn at the point where the slope of the curve on the low temperature side of the melting peak becomes maximum. It was. The temperature at the intersection of the straight line extended to the high temperature side and the tangent (tangent 1) was defined as the solidus temperature. In addition, for the obtained differential scanning calorimetry (DSC) curve, a straight line obtained by extending the base line on the high temperature side to the low temperature side is drawn, and a tangent line (tangent line 2) is obtained at the point where the slope of the curve on the high temperature side of the melting peak becomes maximum Drew. The temperature at the intersection of the straight line extended to the low temperature side and the tangent (tangent 2) was defined as the liquidus temperature.

  From the obtained measurement results, the absolute value of the difference between the solidus temperature of the solder particles and the liquidus temperature of the solder particles was calculated.

(2) Content of tin, bismuth, and indium in 100% by weight of metal contained in solder particles The content of tin, bismuth, and indium in 100% by weight of metal contained in solder particles was determined by high frequency inductively coupled plasma emission. Measurement was performed using a spectroscopic analyzer (“ICP-AES” manufactured by Horiba, Ltd.).

(3) Viscosity of conductive material (ηsp) at solidus temperature of solder particles
Using the obtained conductive material, the viscosity (ηsp) of the conductive material at the solidus temperature of the solder particles was measured. The viscosity (ηsp) of the conductive material at the solidus temperature of the solder particles is STRESSTECH (manufactured by REOLOGICA), strain control 1 rad, frequency 1 Hz, heating rate 20 ° C./min, measurement temperature range 25 ° C. to 200 ° C. (However, when the solidus temperature of the solder particles exceeds 200 ° C., the upper limit of the temperature is taken as the solidus temperature of the solder particles).

(4) Solder placement accuracy on the electrode In the obtained connection structure, 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. When the portion was viewed, the ratio X of the area where the solder portion in the connection portion was arranged in the area of 100% of the portion where the first electrode and the second electrode face each other was evaluated. The placement accuracy of the solder on the electrode was determined according to the following criteria.

[Criteria for solder placement accuracy on electrodes]
〇〇〇: Ratio X is 90% or more 〇: Ratio X is 80% or more and less than 90% 〇: Ratio X is 70% or more and less than 80% ×: Ratio X is less than 70%

(5) Conductivity reliability between upper and lower electrodes In the obtained connection structure (n = 15), the connection resistance per connection portion between the upper and lower electrodes was measured by a four-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.

[Judgment criteria for conduction reliability]
〇〇〇: Average value of connection resistance is 50mΩ or less 〇〇: Average value of connection resistance is more than 50mΩ and less than 70mΩ 〇: Average value of connection resistance is more than 70mΩ and less than 100mΩ ×: Average value of connection resistance is more than 100mΩ Or there is a bad connection

  The results are shown in Tables 1 to 3 below.

  The same tendency was observed even when using a resin film, a flexible flat cable, and a rigid flexible substrate.

DESCRIPTION OF SYMBOLS 1,1X ... Connection structure 2 ... 1st connection object member 2a ... 1st electrode 3 ... 2nd connection object member 3a ... 2nd electrode 4, 4X ... Connection part 4A, 4XA ... Solder part 4B, 4XB ... Cured part 11 ... Conductive material 11A ... Solder particles 11B ... Thermosetting component

Claims (12)

Including a thermosetting component and solder particles;
The absolute value of the difference between the solidus temperature of the solder particles and the liquidus temperature of the solder particles is 5 ° C. or more,
The conductive material in which the content of the solder particles is 15% by weight or more in 100% by weight of the conductive material.   The conductive material according to claim 1, wherein a viscosity of the conductive material at a solidus temperature of the solder particles is 0.1 Pa · s or more and 50 Pa · s or less.   The conductive material according to claim 1, wherein the solder particles include bismuth, indium, silver, copper, or tin.   The conductive material according to claim 3, wherein a content of bismuth is 1 wt% or more and 58 wt% or less in 100 wt% of the metal contained in the solder particles.   5. The conductive material according to claim 3, wherein the content of indium is 1 wt% or more and 52 wt% or less in 100 wt% of the metal contained in the solder particles.   The conductive material according to claim 1, wherein a solidus temperature of the solder particles is 115 ° C. or higher and 220 ° C. or lower.   The conductive material according to claim 1, wherein a particle diameter of the solder particles is 0.01 μm or more and 30 μm or less.   The conductive material according to claim 1, which is a conductive paste. A first connection object member having a first electrode on its surface;
A second connection target member having a 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 material according to any one of claims 1 to 8,
A connection structure in which the first electrode and the second electrode are electrically connected by a solder portion in the connection portion.   When 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, the first electrode and the second electrode 10. The connection structure according to claim 9, wherein the solder portion in the connection portion is arranged in 50% or more of the area of 100% of the portion facing the two electrodes. Using the conductive material according to claim 1, disposing the conductive material on the surface of the first connection target member having the first electrode on the surface;
On the surface opposite to the first connection target member side of the conductive material, the second connection target member having the second electrode on the surface is opposed to the first electrode and the second electrode. A step of arranging to
By heating the conductive material above the liquidus temperature of the solder particles, a connection portion connecting the first connection target member and the second connection target member is formed of the conductive material. And the manufacturing method of a connection structure provided with the process of electrically connecting a said 1st electrode and a said 2nd electrode with the solder part in the said connection part.   When 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, the first electrode and the second electrode The manufacturing method of the connection structure of Claim 11 which obtains the connection structure by which the solder part in the said connection part is arrange | positioned in 50% or more out of 100% of the area of the part which opposes two electrodes .

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