KR20170007724A - Conductive paste, production method for conductive paste, connection structure, and production method for connection structure - Google Patents

Abstract

The present invention provides a conductive paste capable of enhancing application workability and capable of efficiently disposing conductive particles on an electrode and improving reliability of conduction between electrodes. The conductive paste according to the present invention comprises a thermosetting component and a plurality of conductive particles, wherein the thermosetting component contains a thermosetting compound which is solid at 25 占 폚 and a thermosetting agent, and the thermosetting compound Are dispersed in the form of particles.

Description

TECHNICAL FIELD [0001] The present invention relates to a conductive paste, a method of manufacturing a conductive paste, a connection structure, and a method of manufacturing a connection structure,

The present invention relates to a conductive paste containing conductive particles and a method for producing the conductive paste. The present invention also relates to a connection structure using the conductive paste and a manufacturing method of the connection structure.

Anisotropic conductive paste such as anisotropic conductive paste and anisotropic conductive film are widely known. In the anisotropic conductive material, the conductive particles are dispersed in the binder resin.

The anisotropic conductive material can be used for various connection structures, for example, connection (FOG (Film on Glass)) between a flexible printed board and a glass substrate, connection (COF (Chip on Film)) between a semiconductor chip and a flexible printed board, (COG (Chip on Glass)) between a semiconductor chip and a glass substrate, and connection (FOB (Film on Board)) between a flexible printed substrate and a glass epoxy substrate.

When the electrodes of the flexible printed circuit board and the electrodes of the glass epoxy substrate are electrically connected by the anisotropic conductive material, an anisotropic conductive material containing conductive particles is disposed on the glass epoxy substrate. Subsequently, the flexible printed circuit board is laminated and heated and pressed. Thereby, the anisotropic conductive material is cured, and the electrodes are electrically connected via the conductive particles to obtain a connection structure.

As an example of the anisotropic conductive material, Patent Document 1 discloses an adhesive tape comprising a resin layer containing a thermosetting resin, a solder component, and a curing agent, wherein the solder component and the curing agent are present in the resin layer. This adhesive tape is in the form of a film, not a paste.

Further, Patent Document 1 discloses a bonding method using the adhesive tape. More specifically, the first substrate, the adhesive tape, the second substrate, the adhesive tape, and the third substrate are laminated in this order from below to obtain a laminate. At this time, the first electrode provided on the surface of the first substrate and the second electrode provided on the surface of the second substrate are opposed to each other. The second electrode provided on the surface of the second substrate is opposed to the third electrode provided on the surface of the third substrate. Then, the laminate is heated to a predetermined temperature to be bonded. Thus, a connection structure is obtained.

Further, Patent Document 2 discloses an anisotropic conductive material comprising (A) a silica filler having an average particle diameter of 3 to 100 nm and subjected to hydrophobic treatment, (B) an adhesive component, and (C) conductive particles . In Patent Document 2, the amount of the silica filler is 10 to 60 mass% with respect to the total amount of the adhesive component.

(2) rubber-like polymer fine particles having a primary particle diameter of 5 占 퐉 or less and having a softening point temperature of 0 占 폚 or lower; (3) an epoxy resin having an average particle diameter of 5 占 퐉 or less; (4) an anisotropic conductive material containing a high softening point polymer fine particle having a primary particle diameter of 2 탆 or less and a softening point temperature of 50 캜 or higher.

WO2008 / 023452A1 Japanese Patent Application Laid-Open No. 2011-233633 Japanese Patent Application Laid-Open No. 2000-345010

The adhesive tape described in Patent Document 1 is in the form of a film, not a paste. As a result, it is difficult to efficiently dispose the solder powder on the electrode (line). For example, in the adhesive tape described in Patent Document 1, a part of the solder powder is likely to be disposed in an area (space) where no electrode is formed. The solder powder disposed in the region where no electrode is formed does not contribute to the conduction between the electrodes.

Further, even in an anisotropic conductive paste containing a solder powder, the solder powder may not be efficiently arranged on the electrode (line). In the case of an anisotropic conductive material as described in Patent Document 2, the coating workability may be low when applied by screen printing or the like.

Further, if the viscosity of the anisotropic conductive paste containing the solder powder is made low, the solder powder is likely to move on the electrode (line). However, if the viscosity of the anisotropic conductive paste is lowered, the thickness of the anisotropic conductive paste layer after the application becomes too thin, or the anisotropic conductive paste is excessively flowed, and is easily disposed in an unintended region.

(1) a liquid epoxy resin in a temperature range of 0 to 50 캜; and (1-2) a solid epoxy resin in a temperature range of 0 to 50 캜. It is described that a mixture of resins is used. However, in Patent Document 3, for example, in the examples, "Epiclon EP-1004" which is a bisphenol A type epoxy resin is dissolved in 1,6-hexanediol diglycidyl ether, and anisotropic conductive paste , There is only a specific example in which a solid epoxy resin is dissolved. As such, the epoxy resin is not limited to a solid state in the anisotropic conductive paste, but epoxy resin is generally used in a dissolved state.

An object of the present invention is to provide a conductive paste and a conductive paste production method capable of enhancing the application workability and efficiently arranging the conductive particles on the electrode and improving the reliability of the conduction between the electrodes. The present invention also provides a connection structure using the conductive paste and a manufacturing method of the connection structure.

According to a broad aspect of the present invention, there is provided a thermosetting resin composition comprising a thermosetting component and a plurality of conductive particles, wherein the thermosetting component comprises a thermosetting compound which is solid at 25 占 폚 and a thermosetting agent, There is provided a conductive paste in which the compound is dispersed in a particulate form.

In a specific aspect of the conductive paste according to the present invention, the conductive paste contains a thermosetting compound which is liquid at 25 占 폚.

In a specific aspect of the conductive paste according to the present invention, the thermosetting compound solid at 25 캜 is a thermosetting epoxy compound solid at 25 캜.

In one particular aspect of the conductive paste according to the present invention, the thermosetting compound which is solid at 25 占 폚 has a melting point different from that of the first thermosetting compound at 25 占 폚 and a solid And a second thermosetting compound.

It is preferable that the conductive particles have solder on the conductive outer surface, more preferably solder particles.

In a specific aspect of the conductive paste according to the present invention, the viscosity of the solder in the conductive particle at the melting point of -5 DEG C and at 5 rpm is not more than the viscosity at -5 DEG C and 0.5 rpm of the solder in the conductive particle The ratio is 1 or more and 2 or less.

In a specific aspect of the conductive paste according to the present invention, the particulate thermosetting compound has a particle diameter of 1 占 퐉 or more and 40 占 퐉 or less.

In a specific aspect of the conductive paste according to the present invention, the ratio of the viscosity at 25 占 폚 and 5 rpm to the viscosity at 25 占 폚 and 0.5 rpm is not less than 2.5 and not more than 7; in other specific aspects, the viscosity at 25 占 폚 and 5 rpm To the viscosity at 25 DEG C and 0.5 rpm is 4 or more and 7 or less.

In a specific aspect of the conductive paste according to the present invention, the conductive paste includes a flux.

In a specific aspect of the conductive paste according to the present invention, the conductive paste does not include a filler, or the conductive paste contains an amount of 1 wt% or less of 100 wt% of the conductive paste.

According to a broad aspect of the present invention, there is provided a method for producing a conductive paste as described above, which comprises mixing a thermosetting component containing a thermosetting compound which is solid at 25 DEG C and a thermosetting agent, and a plurality of conductive particles to obtain a mixture, The thermosetting compound solid at 25 占 폚 is heated to a temperature not lower than the melting point of the thermosetting compound solid at 25 占 폚 and less than the curing temperature of the thermosetting component so that the thermosetting compound solid at 25 占 폚 is melted and then solidified, Or a mixture of a thermosetting component containing a thermosetting compound and a thermosetting compound which is solid at 25 DEG C and is solid at 25 DEG C and a thermosetting component containing a plurality of conductive particles at 25 DEG C, , And the thermosetting compound which is solid at 25 DEG C is a particle The production method of the conductive paste, to obtain a conductive paste that is dispersed is provided.

According to a broad aspect of the present invention, there is provided a liquid crystal display device comprising a first connection target member having at least one first electrode on its surface, a second connection target member having at least one second electrode on its surface, The first electrode and the second electrode are electrically connected to each other by the conductive particles in the connection portion, and the connection portion is formed by the conductive paste described above, A connection structure is provided.

According to a broad aspect of the present invention, there is provided a method of manufacturing a conductive paste, comprising the steps of: disposing the conductive paste on a surface of a first connection target member having at least one first electrode on a surface thereof using the conductive paste; Arranging a second connection target member having at least one second electrode on a surface on a surface opposite to the first connection target member side such that the first electrode and the second electrode face each other; The connecting portion connecting the first connection target member and the second connection target member is formed by the conductive paste by heating the conductive paste at a temperature equal to or higher than the melting point of the solid thermosetting compound at a temperature higher than the curing temperature of the thermosetting component And electrically connecting the first electrode and the second electrode with the conductive particles in the connection portion, A method of manufacturing a connection structure is provided.

In a specific aspect of 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 paste is not subjected to pressing, Is weighted.

It is preferable that the second connection target member is a resin film, a flexible printed circuit board, a flexible flat cable, or a rigid flexible substrate.

The conductive paste according to the present invention comprises a thermosetting component and a plurality of conductive particles, wherein the thermosetting component contains a thermosetting compound which is solid at 25 占 폚 and a thermosetting agent, The thermosetting compound which is solid in the form of particles is dispersed in the form of particles, so that the coating performance of the conductive paste can be improved. In addition, when the electrodes are electrically connected using the conductive paste according to the present invention, the conductive particles can be efficiently arranged on the electrodes, and the reliability of the conduction between the electrodes can be improved.

BRIEF DESCRIPTION OF DRAWINGS FIG. 1 is a partially cut-away front sectional view schematically showing a connection structure obtained by using a conductive paste according to an embodiment of the present invention; FIG.
2 (a) to 2 (c) are cross-sectional views for explaining respective steps of an example of a method of manufacturing a connection structure using a conductive paste according to an embodiment of the present invention.
3 is a partial cutaway front sectional view showing a modification of the connection structure.
4 is a cross-sectional view schematically showing conductive particles usable in a conductive paste according to an embodiment of the present invention.
5 is a cross-sectional view showing a modified example of the conductive particle.
6 is a cross-sectional view showing another modification of the conductive particle.
Fig. 7 is an image showing a thermosetting compound dispersed in particles in the conductive paste according to one embodiment of the present invention. Fig.

Hereinafter, the details of the present invention will be described.

The conductive paste according to the present invention includes a thermosetting component and a plurality of conductive particles. In the conductive paste according to the present invention, the thermosetting component contains a thermosetting compound and a thermosetting agent which are solid at 25 占 폚. Among the conductive pastes according to the present invention, the thermosetting compound which is solid at 25 DEG C is dispersed in particulate form.

In the conductive paste according to the present invention, since the above-described constitution is employed, the application workability can be improved. The conductive paste according to the present invention can be preferably applied by a coating method such as a dispenser and screen printing. If the viscosity of the anisotropic conductive paste is lowered, the conductive particles tend to move on the electrode (line). In the conductive paste, the fact that the thermosetting compound, which is solid at 25 占 폚, is dispersed in a particulate form contributes greatly to enhance the application workability. For example, the viscosity of the conductive paste is appropriately increased, and the thixotropy of the conductive paste is appropriately developed, so that the thickness of the conductive paste layer after the application is difficult to be thinned and the conductive paste is difficult to flow excessively, It is difficult to be placed in an unintended area. On the other hand, if the filler is mixed in a predetermined amount in order to increase the viscosity of the conductive paste, the filler hinders the movement of the conductive particles onto the electrode. On the other hand, the thermosetting compound which is solid at 25 占 폚 hardly obstructs the movement of the conductive particles onto the electrodes as compared with the filler. Particularly, when the thermosetting compound becomes a liquid phase upon movement of the conductive particles onto the electrode, the thermosetting compound that has become a liquid does not disturb the movement of the conductive particles onto the electrode.

Particularly, in the conductive paste according to the present invention, since the above configuration is employed, when the electrodes are electrically connected, a plurality of conductive particles are easily collected between the first electrode and the second electrode, (Lines). In addition, a part of the plurality of conductive particles is hardly arranged in a region where no electrode is formed (space), so that the amount of conductive particles disposed in an area where no electrode is formed can be significantly reduced. Therefore, the conduction reliability between the first electrode and the second electrode can be improved. In addition, it is possible to prevent the electrical connection between the electrodes adjacent to each other in the transverse direction which should not be connected, and the insulation reliability can be improved. This effect is obtained because it is considered that the thermosetting compound which is solid at 25 占 폚 is less likely to interfere with the movement of the conductive particles onto the electrode as compared with the filler.

In the conductive paste according to the present invention, both of the effect of improving the coating workability and the effect of improving the conduction reliability between the electrodes achieved by the efficient movement of the conductive particles onto the electrodes can be obtained. Further, in the conductive paste according to the present invention, when the conductive particles have the solder on the conductive outer surface, the constitution of the particulate thermosetting compound and the constitution of the conductive particles easily moveable in the conductive paste increase, And more effectively. Further, in the conductive paste according to the present invention, when the conductive particles are solder particles, the constitution of the particulate thermosetting compound and the constitution of the conductive particles particularly easy to move in the conductive paste are increased, Thereby effectively exerting the effect.

The method for producing a conductive paste according to the present invention comprises the steps of (1) mixing a thermosetting component containing a thermosetting compound solid at 25 ° C and a thermosetting agent, and a plurality of conductive particles to obtain a mixture, The thermosetting compound having a solid content at 25 DEG C is dispersed in a particulate state by melting the thermosetting compound at 25 DEG C at a temperature not lower than the melting point of the thermosetting compound that is solid at 25 DEG C and less than the curing temperature of the thermosetting component at 25 DEG C, Or (2) a mixture of a thermosetting component containing a thermosetting compound and a thermosetting agent, which is particulate and solid at 25 DEG C, and a plurality of conductive particles, after the thermosetting compound which is solid at 25 DEG C is converted into a particulate form , And the thermosetting thermosetting epoxy compound solid at 25 [deg. To obtain a conductive paste, which is. The conductive paste according to the present invention can be easily obtained by the method for producing a conductive paste according to the present invention. In the case of the method (2), when the thermosetting compound which is solid at 25 占 폚 is made into a particulate form, the thermosetting agent may be already mixed, and if necessary, the thermosetting compound which is liquid at 25 占 폚 may be already mixed. When the thermosetting compound which is solid at 25 占 폚 is a particulate phase, it is preferable that the conductive particles are not mixed.

The conductive particles contained in the conductive paste preferably have solder on the conductive outer surface, and more preferably solder particles. By using such preferable conductive particles, the conductive particles can be arranged on the electrode more efficiently.

The conductive paste according to the present invention can be suitably used in the method for producing a connection structure according to the present invention as follows.

In the method for manufacturing a connection structure according to the present invention, a conductive paste, a first connection object member, and a second connection object member are used. The conductive material used in the method for manufacturing a connection structure according to the present invention is not a conductive film but a conductive paste. The conductive paste includes a plurality of conductive particles and a thermosetting component. The first connection target member has at least one first electrode on its surface. The second connection target member has at least one second electrode on its surface.

A method of manufacturing a connection structure according to the present invention includes the steps of disposing the conductive paste on the surface of the first connection target member and forming a conductive paste on the surface of the conductive paste opposite to the first connection object side, Heating the conductive paste at a temperature not lower than the melting point of the thermosetting compound solid at 25 캜 and not lower than a setting temperature of the thermosetting component at 25 캜, The connection portion connecting the first connection target member and the second connection target member is formed by the conductive paste and the first electrode and the second electrode are electrically connected to each other by the conductive particles in the connection portion And a connecting step.

In the method of 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 weight of the second connection object member is not applied to the conductive paste, . In the method of 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 paste is subjected to a pressure exceeding the force of the weight of the second connection object member It is preferable not to apply.

In the method of manufacturing a connection structure according to the present invention, since the above configuration is adopted, a plurality of conductive particles are easily collected between the first electrode and the second electrode, and a plurality of conductive particles are efficiently arranged on the electrode . In addition, a part of the plurality of conductive particles is hardly arranged in a region where no electrode is formed (space), so that the amount of conductive particles disposed in an area where no electrode is formed can be significantly reduced. Therefore, the conduction reliability between the first electrode and the second electrode can be improved. In addition, it is possible to prevent the electrical connection between the electrodes adjacent to each other in the transverse direction which should not be connected, and the insulation reliability can be improved.

As described above, in order to efficiently dispose a plurality of conductive particles on the electrode and considerably reduce the amount of the conductive particles disposed in the region where no electrode is formed, it is necessary to use a conductive paste other than the conductive film , The present inventors have found out.

In the step of disposing the second connection target member and the step of forming the connection portion, if the weight of the second connection target member is applied to the conductive paste without applying pressure, The conductive particles disposed in the region where the conductive particles are not formed are more likely to gather between the first electrode and the second electrode so that the plurality of conductive particles can be efficiently arranged on the electrode (line) The present inventors have found out. The present invention employs a configuration in which a conductive paste is used instead of a conductive film and a configuration in which the weight of the second connection target member is applied to the conductive paste without applying pressure is used in combination. The effect of the invention is achieved at a higher level, which is significant.

In addition, in WO2008 / 023452A1, it is described that, from the viewpoint of efficiently moving the solder powder on the electrode surface, the solder powder is pressed at a predetermined pressure at the time of bonding, and the pressing pressure is higher than that , It is described that the pressure is 0 MPa or more, preferably 1 MPa or more, and even if the pressure to be intentionally applied to the adhesive tape is 0 MPa, by the self weight of the member disposed on the adhesive tape, A predetermined pressure may be applied to the surface of the substrate. In WO2008 / 023452A1, it is described that the pressure to be intentionally applied to the adhesive tape may be 0 MPa. However, there is no description about the difference in the effect when the pressure exceeding 0 MPa is applied and when the pressure is 0 MPa.

If the conductive paste is used instead of the conductive film, the thickness of the connection portion can be appropriately adjusted in accordance with the application amount of the conductive paste. On the other hand, in the case of the conductive film, in order to change or adjust the thickness of the connecting portion, there is a problem that a conductive film having a different thickness or a conductive film having a predetermined thickness must be prepared.

In the method of manufacturing a connection structure according to the present invention, when the conductive particles are conductive particles having solder on the conductive outer surface or solder particles, it is preferable to heat the solder particles to the melting point or more of the solder Do. In this case, the first electrode and the second electrode are more firmly bonded to each other by the solder portion solidified after melting. As a result, the conduction reliability between the electrodes is further enhanced.

Best Mode for Carrying Out the Invention Hereinafter, the present invention will be clarified by explaining specific embodiments and examples of the present invention with reference to the drawings.

First, Fig. 1 schematically shows a partially cut-away front cross-sectional view of a connection structure obtained by using a conductive paste according to an embodiment of the present invention.

The connection structure 1 shown in Fig. 1 has a first connection target member 2, a second connection target member 3, a first connection target member 2 and a second connection target member 3, And a connecting portion 4 connected thereto. The connecting portion 4 is formed of a conductive paste containing a thermosetting component and a plurality of conductive particles. In this conductive paste, the thermosetting component contains a thermosetting compound which is solid at 25 占 폚 and a thermosetting agent. In the conductive paste, the thermosetting compound which is solid at 25 占 폚 is dispersed in a particulate form. In the present embodiment, solder particles are used as the conductive particles.

The connecting portion 4 has a solder portion 4A (conductive particle) in which a plurality of solder particles are gathered and joined together and a cured portion 4B in which a thermosetting component is thermally cured.

The first connection target member 2 has a plurality of first electrodes 2a on its surface (upper surface). The second connection target member 3 has a plurality of second electrodes 3a on its surface (lower surface). The first electrode 2a and the second electrode 3a are electrically connected by the soldering 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 connecting portion 4, there is no solder in a region (cured portion 4B) different from the soldering portion 4A gathered between the first electrode 2a and the second electrode 3a. In the region different from the soldering portion 4A (the portion of the hardened portion 4B), there is no solder spaced apart from the soldering portion 4A. If the amount is small, solder may be present in a region (cured portion 4B) different from the soldering portion 4A gathered between the first electrode 2a and the second electrode 3a.

As shown in Fig. 1, in the connection structure 1, after the plurality of solder particles are melted, the melts of the solder particles are solidified after the surface of the electrode is widened, and the solder portion 4A is formed. This increases the connection area between the solder portion 4A and the first electrode 2a and between the solder portion 4A and the second electrode 3a. That is, by using the solder particles, the solder portion 4A, the first electrode 2a, and the solder portion 4A can be formed in the same manner as in the case where the conductive outer surface is made of conductive particles of metal such as nickel, And the second electrode 3a. As a result, conduction reliability and connection reliability in the connection structure 1 are enhanced. The conductive paste may contain flux. The flux contained in the conductive paste gradually becomes inactive by heating.

In the connection structure 1 shown in Fig. 1, all of the soldering portions 4A are located in the regions where the first and second electrodes 2a and 3a face each other. The connection structure 1X of the modification shown in Fig. 3 differs from the connection structure 1 shown in Fig. 1 only in the connection portion 4X. The connecting portion 4X has a soldering portion 4XA and a cured portion 4XB. Most of the soldering portion 4XA is located in the region where the first and second electrodes 2a and 3a face each other and the soldering portion 4XA is part of the first and second electrodes 2a and 3a, But may be sideways from the opposed regions of the electrodes 2a and 3a. The soldering portion 4XA that is laterally projected from the opposing region of the first and second electrodes 2a and 3a is part of the soldering portion 4XA and is not solder spaced apart from the soldering portion 4XA . In the present embodiment, the amount of solder spaced apart from the solder portion can be reduced, but solder spaced apart from the solder portion may be present in the hardened portion.

When the usage amount of the solder particles is reduced, it is easy to obtain the connection structure 1. If the amount of solder particles used is increased, it is easy to obtain the connection structure 1X.

Next, an example of a method of manufacturing the connection structure 1 using the conductive paste according to one embodiment of the present invention will be described.

First, a first connection target member 2 having a first electrode 2a on its surface (upper surface) is prepared. 2 (a), a thermosetting component 11B and a conductive paste 11 including a plurality of solder particles 11A are formed on the surface of the first connection target member 2, (First step). The conductive paste 11 is disposed on the surface of the first connection target member 2 on which the first electrode 2a is provided. The solder particles 11A are arranged on both the first electrode 2a (line) and the region (space) where the first electrode 2a is not formed after the conductive paste 11 is disposed.

The method of disposing the conductive paste 11 is not particularly limited, and examples thereof include coating with a dispenser, screen printing, and ejection with an inkjet apparatus. Among them, screen printing is preferable. By using the conductive paste according to the present invention, the workability of coating by screen printing is remarkably improved, so that even if screen printing is performed, the conductive paste layer can be formed to have a predetermined thickness and excessive spreading of the conductive paste can be suppressed, It is difficult for the paste to be placed in an unintended area.

Furthermore, a second connection target member 3 having a second electrode 3a on its surface (lower surface) is prepared. 2 (b), in the conductive paste 11 on the surface of the first connection target member 2, the conductive paste 11 is separated from the first connection target member 2 side The second connection target member 3 is arranged on the surface on the opposite side (second step). The second connection target member 3 is disposed on the surface of the conductive paste 11 from the second electrode 3a side. At this time, the first electrode 2a and the second electrode 3a are opposed to each other.

Subsequently, the conductive paste 11 is heated to a temperature not lower than the melting point of the thermosetting compound solid at 25 占 폚 and not lower than the hardening temperature of the thermosetting component 11B (third step). That is, the conductive paste 11 is heated at a temperature which is lower than the melting point of the thermosetting compound solid at 25 DEG C and the curing temperature of the thermosetting component 11B. Preferably, the conductive paste 11 is heated at a temperature not lower than the melting point of the solder, that is, not less than the melting point of the solder particles 11A. During this heating, the solder particles 11A existing in the regions where the electrodes are not formed are gathered between the first electrode 2a and the second electrode 3a (magnetic cohesion effect). In the present embodiment, since the conductive paste is used instead of the conductive film, the solder particles 11A are effectively gathered between the first electrode 2a and the second electrode 3a. Further, the solder particles 11A are melted and bonded to each other. Further, the thermosetting component 11B thermally cures. As a result, as shown in Fig. 2C, the connecting portion 4 connecting the first connection target member 2 and the second connection target member 3 is formed by the conductive paste 11 do. The connecting portion 4 is formed by the conductive paste 11 and the plurality of solder particles 11A are bonded to form the solder portion 4A and the thermosetting component 11B is thermally cured to form the cured portion 4B . When the solder particles 3 move quickly, the movement of the solder particles 3, which are not located between the first electrode 2a and the second electrode 3a, starts, and then the first electrode 2a and the second electrode 3a, It is not necessary to keep the temperature constant until the movement of the solder particles 3 is completed between the solder balls 3a.

In addition, a preliminary heating step may be provided in the entire third step. This preliminary heating step is a step of heating the conductive paste 11 to a temperature of not higher than the melting temperature of the solder and substantially not thermally curing the thermosetting component 11B in a state in which the weight of the second connection target member 3 is applied, And heating for 60 seconds to 60 seconds. By providing this step, the action to be collected between the first electrode and the second electrode of the solder particles is further enhanced, and the voids that may occur between the first connection object member and the second connection object member can be suppressed have.

In the present embodiment, no pressure is applied in the second step and the third step. In the present embodiment, the weight of the second connection target member 3 is applied to the conductive paste 11. This allows the solder particles 11A to effectively gather between the first electrode 2a and the second electrode 3a at the time of forming the connection portion 4. Further, in at least one of the second step and the third step, if the pressing is performed, the action of the solder particles to gather between the first electrode and the second electrode is inhibited. This was discovered by the present inventors.

In this manner, the connection structure 1 shown in Fig. 1 is obtained. Further, the second step and the third step may be performed continuously. After the second step is performed, the laminate of the obtained first connection target member 2, the conductive paste 11 and the second connection target member 3 is moved to the heating portion, and the third step is performed . In order to perform the heating, the laminate may be disposed on the heating member, or the laminate may be disposed in the heated space.

The heating temperature in the third step is preferably not less than the melting point of the thermosetting compound solid at 25 DEG C and not more than the curing temperature of the thermosetting component (11B), preferably not less than the melting point of the solder and not more than the curing temperature of the thermosetting component. The heating temperature is preferably 130 占 폚 or higher, more preferably 160 占 폚 or higher, preferably 450 占 폚 or lower, more preferably 250 占 폚 or lower, further preferably 200 占 폚 or lower.

The temperature of the preliminary heating step is preferably 100 占 폚 or higher, more preferably 120 占 폚 or higher, further preferably 140 占 폚 or higher, preferably 160 占 폚 or lower, more preferably 150 占 폚 or lower.

The first connection target member may have at least one first electrode. It is preferable that the first connection target member has a plurality of first electrodes. The second connection target member may have at least one second electrode. The second connection target member preferably has a plurality of second electrodes.

The first and second connection target members are not particularly limited. Specific examples of the first and second connection target members include electronic parts such as a semiconductor chip, a capacitor and a diode, and a resin film, a printed board, a flexible printed board, a flexible flat cable, a rigid flexible board, a glass epoxy board and a glass And electronic parts such as circuit boards such as boards. It is preferable that the first and second connection target members are electronic parts.

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 circuit board, a flexible flat cable, or a rigid flexible substrate. It is preferable that the second connection target member is a resin film, a flexible printed circuit board, a flexible flat cable, or a rigid flexible substrate. Resin films, flexible printed boards, flexible flat cables and rigid flexible boards have high flexibility and relatively light weight properties. In the case where a conductive film is used for connection of such members to be connected, the conductive particles tend not to collect on the electrodes. In contrast, since the conductive paste according to the present invention is used, even if a resin film, a flexible printed circuit board, a flexible flat cable, or a rigid flexible substrate is used, the conductive particles can be efficiently collected on the electrode, Can be sufficiently increased. In the case of using a resin film, a flexible printed circuit board, a flexible flat cable, or a rigid flexible substrate, the effect of improving the reliability of the conduction between the electrodes by not applying the pressure is better compared with the case of using other members to be connected such as a semiconductor chip Can be obtained more effectively.

Examples of the electrode provided on the member to be connected include metal electrodes such as a gold electrode, a nickel electrode, a tin electrode, an aluminum electrode, a copper electrode, a silver electrode, a molybdenum electrode, a SUS electrode, and a tungsten electrode. When the connection target member is a flexible printed circuit board or a flexible flat cable, 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, it is preferable that the electrode is an aluminum electrode, a copper electrode, a molybdenum electrode, a silver electrode, or a tungsten electrode. When the electrode is an aluminum electrode, it may be an electrode formed only of aluminum, or an electrode in which an aluminum layer is laminated on the surface of the metal oxide layer. Examples of the material of 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.

The distance D1 of the connection portion at the position where the first electrode and the second electrode face each other is preferably 3 m or more, more preferably 10 m or more, preferably 100 m or less, more preferably 75 Mu m or less. When the distance D1 is equal to or larger than the lower limit, the connection reliability of the connecting portion and the member to be connected is further increased. When the distance D1 is less than the upper limit, the conductive particles are more likely to gather on the electrode at the time of forming the connecting portion, and the reliability of the conduction between the electrodes is further enhanced.

The particle diameter of the thermosetting compound which is solid at 25 占 폚 in the conductive paste in the conductive paste is preferably 0.1 占 퐉 or more, more preferably 1 占 퐉 or more, preferably 40 占 퐉 or less, more preferably 30 占 퐉 or less, More preferably 20 mu m or less, particularly preferably 10 mu m or less.

The particle diameter of the thermosetting compound which is solid at 25 占 폚 in the particulate state indicates the number average particle diameter. The particle diameter of the thermosetting compound solid at 25 占 폚, which is a particulate solid at 25 占 폚, can be obtained by, for example, observing 50 thermosetting compounds solid at 25 占 폚, which are arbitrary particles, with an electron microscope or an optical microscope and calculating an average value.

The viscosity η1 of the conductive paste at 25 ° C. and 5 rpm is preferably 10 Pas · s or more, more preferably 50 Pas · s or more, further preferably 100 Pas · s or more, preferably 800 Pas · s or less , More preferably not more than 600 Pa 占 퐏, still more preferably not more than 500 Pa 占 퐏. When the viscosity? 1 is not less than the lower limit and not more than the upper limit, the coating workability of the conductive paste and the arrangement accuracy of the conductive particles are further enhanced.

The viscosity? 2 at 25 ° C and 0.5 rpm of the conductive paste is preferably 1 Pas · s or more, and preferably 100 Pas · s or less. When the viscosity? 2 is not less than the lower limit and not more than the upper limit, the coating workability of the conductive paste and the arrangement accuracy of the conductive particles are further enhanced.

The ratio? 1 /? 2 to the viscosity? 2 at 25 占 폚 and 0.5 rpm of the viscosity? 1 at 25 占 폚 and 5 rpm is preferably at least 1, more preferably at least 2.5, still more preferably at least 4, Is preferably 7 or less, more preferably 6 or less, further preferably 5 or less. When the ratio eta / [eta] 2 is not less than the lower limit and not more than the upper limit, the coating workability of the conductive paste and the placement accuracy of the conductive particles are further increased, and the reliability of the conduction between the electrodes is effectively increased.

When the conductive particles have solder on the conductive outer surface, the melting point of the solder in the conductive particles is set to T 占 폚. The ratio (? 1 '/? 2') of the viscosity? 1 'at (T-5) ° C and 5 rpm to the viscosity? 2' at (T- 2 or less. If the ratio? 1 '/? 2' is not less than the lower limit and not more than the upper limit, the arrangement accuracy of the conductive particles is further increased, and the reliability of the conduction between the electrodes is effectively increased.

The viscosity can be appropriately adjusted to the kind of the blended component, the blending amount of the blended component, and particularly the dispersion state of the thermosetting compound which is solid at 25 占 폚.

The viscosity was measured at 25 DEG C and 5 rpm, at 25 DEG C and 0.5 rpm, at (T-5) DEG C and at 5 rpm and (T-5), using a E-type viscometer Lt; 0 > C and 0.5 rpm.

The conductive paste includes a thermosetting component and a plurality of conductive particles. The thermosetting component includes a thermosetting compound (a curing compound that can be cured by heating) solid at 25 占 폚 and a thermosetting agent. It is preferable that the conductive paste includes a thermosetting compound (a curing compound that can be cured by heating) that is liquid at 25 占 폚. The conductive paste preferably includes a flux. The conductive paste may include a filler.

Hereinafter, other details of the present invention will be described.

(Conductive particles)

The conductive particles electrically connect the electrodes of the member to be connected. The conductive particles are not particularly limited as long as they are conductive particles. The conductive particles may have a conductive portion on a conductive outer surface.

Examples of the conductive particles include conductive particles obtained by coating the surface of an organic particle, inorganic particles other than metal particles, organic-inorganic hybrid particles or metal particles with a conductive layer (metal layer), metal particles composed substantially only of metal .

The conductive particles contained in the conductive paste preferably have solder on the conductive outer surface, and more preferably solder particles. Hereinafter, the conductive particles having solder on the conductive outer surface will be described.

Fig. 4 is a cross-sectional view of conductive particles usable in a conductive paste according to an embodiment of the present invention.

The conductive particles 51 shown in Fig. 4 have base particles 52 (resin particles and the like) and conductive portions 53 disposed on the outer surface 52a of the base particles 52. Fig. The conductive portion 53 is a conductive layer. The conductive portion 53 covers the outer surface 52a of the base particle 52. [ The conductive particles 51 are coated particles in which the outer surface 52a of the base particles 52 is covered with the conductive portions 53. [ Therefore, the conductive particles 51 have the conductive portions 53 on the outer surface 51a.

The conductive portion 53 includes a first conductive portion 54 (first conductive layer) disposed on the outer surface 52a of the base particle 52 and an outer surface 54a of the first conductive portion 54, (A solder layer, a second conductive portion (second conductive layer)) disposed on the soldering portion 55. The surface portion (surface layer) on the outside of the conductive portion 53 is a soldering portion 55. Therefore, the conductive particles 51 have a solder portion 55 as a part of the conductive portion 53 and a solder portion 55 as a part of the conductive layer 53 between the base particles 52 and the solder portion 55. [ (54) separately from the first conductive portion (55). As described above, the conductive portion 53 may have a multilayer structure or may have a laminate structure of two or more layers.

As described above, the conductive portion 53 has a two-layer structure. As in the modification shown in Fig. 5, the conductive particles 61 may have a solder portion 62 as a single conductive portion (conductive layer). In the conductive particles having solder on the conductive outer surface, at least the outer surface portion (surface layer) of the conductive portion in the conductive particle may be a solder portion. However, since the production of the conductive particles is easy, the conductive particles 51 and the conductive particles 51 among the conductive particles 51 are preferable. Further, as in the modification shown in Fig. 6, the solder particles 11A may be used instead of the core-shell particles without having the base particles in the core. In the solder particles 11A, both the center portion and the conductive outer surface are formed by solder.

The conductive particles 51 and 61 and the solder particles 11A can be used for the conductive paste. Among the conductive particles 51 and 61 and the solder particles 11A, the solder particles 11A are particularly preferable from the viewpoint of effectively increasing the reliability of conduction between the electrodes and increasing the connection reliability.

The conductive portion is not particularly limited. Examples of the metal constituting the conductive portion include gold, silver, copper, nickel, palladium and tin. Examples of the conductive layer include a gold layer, a silver layer, a copper layer, a nickel layer, a palladium layer, or a conductive layer containing tin.

From the viewpoint of increasing the contact area between the electrode and the conductive particles and further enhancing the reliability of the conduction between the electrodes, the conductive particles have the resin particle and the conductive layer (first conductive layer) disposed on the surface of the resin particle . From the viewpoint of further enhancing the conduction reliability between the electrodes, it is preferable that the above-mentioned conductive particles are conductive particles whose at least conductive outer surface is a low melting point metal layer. It is more preferable that the conductive particles have a base particle and a conductive layer disposed on the surface of the base particle, and at least the outer surface of the conductive layer is a low melting point metal layer. It is more preferable that the conductive particle has base particles and a conductive portion disposed on the surface of the base particle, and at least the outer surface of the conductive portion is a low melting point metal layer.

The solder is preferably a low melting point metal having a melting point of 450 캜 or lower. The solder particles are preferably low melting point metal particles having a melting point of 450 캜 or lower. The low melting point metal particles are particles containing a low melting point metal. The low melting point metal means a metal having a melting point of 450 캜 or lower. The melting point of the low melting point metal is preferably 300 DEG C or lower, more preferably 160 DEG C or lower. Further, the solder includes tin. The content of tin is preferably at least 30 wt%, more preferably at least 40 wt%, even more preferably at least 70 wt%, particularly preferably at least 90 wt%, of tin in 100 wt% of the metal contained in the solder . If the content of tin in the solder is lower than the lower limit described above, the connection reliability between the solder portion and the electrode is further enhanced.

The content of the tin may be measured by a high frequency inductively coupled plasma emission spectrochemical analyzer ("ICP-AES" manufactured by Horiba Seisakusho Co., Ltd.) or a fluorescent X-ray analyzer ("EDX-800HS" manufactured by Shimadzu Corporation) . ≪ / RTI >

By using the conductive particles having the solder on the conductive outer surface, the solder is melted and bonded to the electrode, so that the solder portion conducts between the electrodes. For example, since the solder portion and the electrode are likely to come into contact with each other not by point contact, the connection resistance is lowered. In addition, the use of the conductive particles having the solder on the conductive outer surface increases the bonding strength between the solder portion and the electrode, and as a result, the solder portion and the electrode are less likely to be peeled off, effectively increasing the conduction reliability and the connection reliability .

The low melting point metal constituting the solder is not particularly limited. The low melting point metal is preferably an alloy containing tin or tin. The alloy includes tin-silver alloy, tin-copper alloy, tin-silver-copper alloy, tin-bismuth alloy, tin-zinc alloy and tin-indium alloy. Among them, it is preferable that the low melting point metal is tin, a tin-silver alloy, a tin-silver-copper alloy, a tin-bismuth alloy, and a tin-indium alloy from the viewpoint of excellent wettability to electrodes. Tin-bismuth alloy, and tin-indium alloy.

It is preferable that the solder is a filler material having a liquidus temperature of 450 DEG C or less based on JIS Z3001: welding terminology. Examples of the composition of the solder include a metal composition including zinc, gold, silver, lead, copper, tin, bismuth, indium and the like. Among them, lead-free tin-indium based (117 캜) or tin-bismuth (139 캜) low melting point is preferable. That is, it is preferable that the solder does not contain lead, and includes tin and indium, or includes tin and bismuth.

The solder may include phosphorus and tellurium and may be nickel, copper, antimony, aluminum, zinc, iron, gold, titanium, germanium, cobalt, bismuth, Manganese, chromium, molybdenum, palladium, and the like. From the viewpoint of further enhancing the bonding strength between the solder portion and the electrode, it is preferable that the solder includes nickel, copper, antimony, aluminum or zinc. From the viewpoint of further increasing the bonding strength between the solder portion and the electrode, the content of these metals for increasing the bonding strength is preferably 0.0001 wt% or more, and preferably 1 wt% or less, in 100 wt% of the solder.

The average particle diameter of the conductive particles is preferably 0.5 占 퐉 or more, more preferably 1 占 퐉 or more, further preferably 3 占 퐉 or more, particularly preferably 5 占 퐉 or more, preferably 100 占 퐉 or less, Is not more than 30 mu m, more preferably not more than 20 mu m, particularly preferably not more than 15 mu m, and most preferably not more than 10 mu m. When the average particle diameter of the conductive particles is not less than the lower limit and not more than the upper limit, the conductive particles can be more efficiently arranged on the electrode. The average particle diameter of the conductive particles is particularly preferably from 3 탆 to 30 탆.

The " average particle diameter " of the conductive particles indicates the number average particle diameter. The average particle diameter of the conductive particles can be obtained, for example, by observing 50 of any conductive particles with an electron microscope or an optical microscope and calculating an average value.

The content of the conductive particles in 100 wt% of the conductive paste is preferably 0.1 wt% or more, more preferably 1 wt% or more, still more preferably 2 wt% or more, further preferably 10 wt% Particularly preferably not less than 20% by weight, most preferably not less than 30% by weight, preferably not more than 80% by weight, more preferably not more than 60% by weight, further preferably not more than 50% by weight. When the content of the conductive particles is lower than or equal to the lower limit and lower than or equal to the upper limit, the conductive particles can be more efficiently arranged on the electrode, and it is easy to arrange a larger number of conductive particles between the electrodes. From the viewpoint of further enhancing conduction reliability, the content of the conductive particles is preferably large.

(Compound that can be cured by heating: a thermosetting component)

The thermosetting compound is not particularly limited as long as it is solid at 25 占 폚 and can be dispersed in the form of particles in the conductive paste. For example, at 25 占 폚, among the conductive paste, the thermosetting compound which is solid at 25 占 폚 is dispersed in particulate form. 7 shows an image of a thermosetting compound dispersed in particles in the conductive paste according to one embodiment of the present invention.

Examples of the thermosetting compound solid at 25 占 폚 include oxetane compounds, epoxy compounds, episulfide compounds, (meth) acrylic compounds, phenol compounds, amino compounds, unsaturated polyester compounds, polyurethane compounds, silicone compounds, polyimide compounds and Polythiol and the like. The thermosetting compound solid at 25 占 폚 may be used alone or in combination of two or more.

From the viewpoint of improving the dispersion state of the thermosetting compound which is solid at 25 DEG C in the conductive paste and exerting the effect of the present invention more effectively, the thermosetting compound which is solid at 25 DEG C is a thermosetting epoxy compound . Further, by using the epoxy compound, the connection reliability is further enhanced.

From the viewpoint of effectively improving the conduction reliability between the electrodes, the melting point of the thermosetting compound solid at 25 DEG C is preferably 40 DEG C or higher, more preferably 70 DEG C or higher, further preferably 90 DEG C or higher, More preferably not higher than 140 ° C, even more preferably not higher than 120 ° C.

From the viewpoint of suppressing the viscosity of the conductive paste to a drastic lowering at the time of melting the thermosetting compound solid at 25 占 폚 and suppressing excessive sedimentation of the conductive particles and consequently increasing the reliability of the conduction between the electrodes effectively, It is preferred that the thermosetting compound comprises a first thermosetting compound that is solid at 25 占 폚 and a second thermosetting compound that has a melting point different from that of the first thermosetting compound and is solid at 25 占 폚.

From the viewpoint of effectively improving the conduction reliability between the electrodes, the absolute value of the difference between the melting point of the first thermosetting compound and the melting point of the second thermosetting compound is preferably 1 DEG C or more, more preferably 5 DEG C or more, still more preferably 10 ° C or higher, preferably 30 ° C or lower, more preferably 20 ° C or lower.

From the viewpoint of improving the dispersion state of the thermosetting compound solid at 25 占 폚 and exerting the effect of the present invention more effectively, it is preferable that the conductive paste contains a thermosetting compound which is liquid at 25 占 폚. Examples of the thermosetting compound which is in a liquid phase at 25 占 폚 include oxetane compounds, epoxy compounds, episulfide compounds, (meth) acrylic compounds, phenol compounds, amino compounds, unsaturated polyester compounds, polyurethane compounds, silicone compounds, Polythiol and the like. The above-mentioned thermosetting compound which is liquid at 25 占 폚 may be used alone or two or more of them may be used in combination.

From the viewpoint of further improving the curability and viscosity of the conductive paste and further improving the connection reliability, it is preferable that the thermosetting compound which is in a liquid phase at 25 캜 is a thermosetting epoxy compound which is liquid at 25 캜.

The total content of the thermosetting compound solid at 25 占 폚 and the thermosetting compound liquid at 25 占 폚 among 100% by weight of the conductive paste is preferably 20% by weight or more, more preferably 40% by weight or more, Preferably not less than 50% by weight, preferably not more than 99% by weight, more preferably not more than 98% by weight, more preferably not more than 90% by weight, particularly preferably not more than 80% by weight. From the viewpoint of further improving the impact resistance, the content of the above-mentioned thermosetting component is preferably large.

The content of the thermosetting compound which is solid at 25 DEG C and the thermosetting epoxy compound which is solid at 25 DEG C in 100 wt% of the conductive paste is preferably 5% by weight or more, more preferably 10% by weight or more, Is not more than 70% by weight, more preferably not more than 50% by weight. If the content of the thermosetting compound which is solid at 25 占 폚 and the thermosetting epoxy compound which is solid at 25 占 폚 is lower than or equal to the lower limit and below the upper limit, the coating workability of the conductive paste and the arrangement accuracy of the conductive particles are further enhanced.

The content of the thermosetting compound which is liquid at 25 占 폚 and the thermosetting epoxy compound which is liquid at 25 占 폚 among 100% by weight of the conductive paste is preferably 5% by weight or more, more preferably 10% by weight or more, Is not more than 70% by weight, more preferably not more than 50% by weight. If the content of the thermosetting compound which is liquid at 25 占 폚 and the thermosetting epoxy compound which is liquid at 25 占 폚 is lower than or equal to the lower limit and above the upper limit, the coating workability of the conductive paste and the arrangement accuracy of the conductive particles are further enhanced.

The difference between the SP value of the thermosetting compound which is solid at 25 占 폚 and that of the thermosetting compound which is liquid at 25 占 폚 is preferably 0.5 or more, more preferably 1 or more, preferably 3 or less, more preferably 2 or less. If the difference in SP value is above the lower limit and below the upper limit, it can be stably present as particles of the thermosetting compound which is solid at 25 占 폚, and the positioning accuracy of the conductive particles in the conductive paste is further enhanced.

(Thermosetting agent: thermosetting component)

The thermosetting agent thermally cures the thermosetting compound. Examples of the heat curing agent include an imidazole curing agent, an amine curing agent, a phenol curing agent, a polythiol curing agent, an acid anhydride, a thermal cationic initiator, and a thermal radical generator. The thermosetting agent may be used alone or in combination of two or more.

Among them, an imidazole curing agent, a polythiol curing agent or an amine curing agent is preferable because the conductive paste can be cured more rapidly at a low temperature. In addition, when the heat curing agent is mixed with the curing compound that can be cured by heating, the storage stability becomes high, and therefore, a latent curing agent is preferable. The latent curing agent is preferably a latent imidazole curing agent, a latent polythiol curing agent or a latent amine curing agent. The thermosetting agent may be coated with a polymer material such as a polyurethane resin or a polyester resin.

The imidazole curing agent is not particularly limited, and examples thereof include 2-methylimidazole, 2-ethyl-4-methylimidazole, 1-cyanoethyl- 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 adduct.

The polythiol curing agent is not particularly limited and includes trimethylolpropane tris-3-mercaptopropionate, pentaerythritol tetrakis-3-mercaptopropionate, and dipentaerythritol hexa-3-mercaptopropionate And the like.

The amine curing agent is not particularly limited and includes hexamethylenediamine, octamethylenediamine, decamethylenediamine, 3,9-bis (3-aminopropyl) -2,4,8,10-tetaspiro [5.5] undecane, bis (4-aminocyclohexyl) methane, metaphenylenediamine, and diaminodiphenylsulfone.

Examples of the thermal cationic curing agent include an iodonium-based cationic curing agent, an oxonium-based cationic curing agent, and a sulfonium-based cationic curing agent. Examples of the iodonium-based cationic curing agent include bis (4-tert-butylphenyl) iodonium hexafluorophosphate and the like. Examples of the oxonium-based cation curing agent include trimethyloxonium tetrafluoroborate and the like. Examples of the sulfonium cation-based curing agent include tri-p-tolylsulfonium hexafluorophosphate and the like.

The heat radical generator is not particularly limited, and examples thereof include an azo compound and an organic peroxide. Examples of the azo compound include azobisisobutyronitrile (AIBN) and the like. Examples of the organic peroxide include di-tert-butyl peroxide and methyl ethyl ketone peroxide.

The reaction initiation temperature (curing temperature) of the heat curing 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 More preferably 150 ° C or lower, particularly preferably 140 ° C or lower. When the reaction initiation temperature of the heat curing agent is not less than the lower limit and not more than the upper limit, the conductive particles are more efficiently arranged on the electrode. The reaction initiation temperature of the thermosetting agent is particularly preferably from 80 캜 to 140 캜.

From the viewpoint of more efficiently arranging the conductive particles on the electrode, the reaction initiation temperature of the heat curing agent is preferably lower than the melting point of the solder in the conductive particle, more preferably 5 deg. C or lower, Or more.

The reaction initiation temperature of the heat curing agent means the temperature at which the exothermic peak in DSC starts rising.

The content of the thermosetting agent is not particularly limited. The content of the thermosetting agent is preferably at least 0.01 part by weight, more preferably at least 1 part by weight, preferably at most 200 parts by weight, more preferably at most 200 parts by weight, per 100 parts by weight of the thermosetting compound solid at 25 캜 More preferably 100 parts by weight or less, still more preferably 75 parts by weight or less, further preferably 50 parts by weight or less, particularly preferably 37.5 parts by weight or less. The content of the thermosetting agent is preferably 0.01 parts by weight or more, more preferably 1 part by weight or more, and even more preferably 1 part by weight or more per 100 parts by weight of the total of 100 parts by weight of the thermosetting compound solid at 25 캜 and the thermosetting compound liquid at 25 캜 Is not more than 200 parts by weight, more preferably not more than 100 parts by weight, further preferably not more than 75 parts by weight. If the content of the heat curing agent is lower than the lower limit described above, it is easy to sufficiently cure the conductive paste. If the content of the thermosetting agent is less than the upper limit, an excess of the thermosetting agent that is not involved in curing after curing is hard to remain, and the heat resistance of the cured product is further increased.

(Flux)

It is preferable that the conductive paste includes a flux. When the conductive particles are conductive particles having solder on the conductive surface, it is preferable to use a flux. By using the flux, the solder can be arranged more effectively on the electrode. The flux is not particularly limited. As the flux, a flux generally used for solder bonding or the like can be used. Examples of the flux include zinc chloride, a mixture of zinc chloride and an inorganic halide, a mixture of zinc chloride and an inorganic acid, a molten salt, a phosphoric acid, a derivative of phosphoric acid, an organic halide, a hydrazine, an organic acid, The flux may be used alone, or two or more fluxes may be used in combination.

Examples of the molten salt include ammonium chloride and the like. Examples of the organic acid include lactic acid, citric acid, stearic acid, glutamic acid and glutaric acid. Examples of the papermaking papers include activated papermaking and inactive papermaking. It is preferable that the flux is an organic acid having two or more carboxyl groups, and a feedstock. The flux may be an organic acid having two or more carboxyl groups, or may be fed. The use of an organic acid having two or more carboxyl groups and a transfer paper makes the reliability of conduction between the electrodes higher.

The above paper is a rosin mainly containing abietic acid. The flux is preferably rosin, more preferably abietic acid. By using this preferable flux, the reliability of conduction between the electrodes is further enhanced.

The melting point of the flux is preferably 50 占 폚 or higher, more preferably 70 占 폚 or higher, even more preferably 80 占 폚 or higher, preferably 200 占 폚 or lower, more preferably 160 占 폚 or lower, still more preferably 150 Lt; 0 > C, more preferably 140 < 0 > C or less. When the melting point of the flux is higher than or equal to the lower limit and lower than or equal to the upper limit, the flux effect is more effectively exerted and the solder particles are more efficiently arranged on the electrode. The melting point of the flux is preferably 80 ° C or higher and 190 ° C or lower. The melting point of the flux is particularly preferably from 80 캜 to 140 캜.

Examples of the flux having a melting point of 80 ° C or more and 190 ° C or less include succinic acid having a melting point of 186 ° C, glutaric acid having a melting point of 96 ° C, adipic acid having a melting point of 152 ° C, pimelic acid having a melting point of 104 ° C, 142 占 폚), benzoic acid (melting point 122 占 폚), malic acid (melting point 130 占 폚), 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 lower than the melting point of the solder in the solder particle, more preferably 5 deg. C or lower, more preferably 10 deg. C or lower More preferable.

From the viewpoint of more efficiently placing the solder on the electrode, the melting point of the flux is preferably lower than the reaction initiation temperature of the thermosetting agent, more preferably 5 deg. C or lower, further preferably 10 deg. C or lower do.

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

The content of the flux in 100 wt% of the conductive paste is preferably 0.5 wt% or more, preferably 30 wt% or less, and more preferably 25 wt% or less. The conductive paste may not contain flux. If the content of the flux is lower than or equal to the lower limit and lower than or equal to the upper limit, it is difficult to further form an oxide film on the surface of the solder and the electrode, and furthermore, the oxide film formed on the surface of the solder and the electrode can be removed more effectively.

(filler)

The conductive paste may include a filler. By using the filler, latent heat expansion of the hardened product of the conductive paste can be suppressed. However, it is preferable not to use a filler from the viewpoint of further enhancing the application workability of the conductive paste and the arrangement accuracy of the conductive particles, and in the case of using a filler, the smaller the content of the filler, the better.

It is preferable that the conductive paste does not include a filler, or that the conductive paste contains 100 wt% of the filler in an amount of 1 wt% or less. When the conductive paste contains a filler, the content of the filler is more preferably 0.5 wt% or less.

Examples of the filler include inorganic fillers such as silica, talc, aluminum nitride and alumina. The filler may be an organic filler or an organic-inorganic composite filler. The filler may be used alone or in combination of two or more.

(Other components)

The conductive paste may contain various additives such as fillers, extenders, softeners, plasticizers, polymerization catalysts, curing catalysts, colorants, antioxidants, heat stabilizers, light stabilizers, ultraviolet absorbents, lubricants, antistatic agents and flame retardants .

Hereinafter, the present invention will be described in detail with reference to examples and comparative examples. The present invention is not limited to the following examples.

Polymer A

Synthesis of first reactant of bisphenol F with 1,6-hexanediol diglycidyl ether and bisphenol F type epoxy resin:

72 parts by weight of bisphenol F (containing 4,4'-methylenebisphenol and 2,4'-methylenebisphenol and 2,2'-methylenebisphenol in a weight ratio of 2: 3: 1), 1,6-hexanediol di 70 parts by weight of glycidyl ether and 30 parts by weight of bisphenol F type epoxy resin ("EPICLON EXA-830CRP" manufactured by DIC Corporation) were put into a three-necked flask and dissolved at 150 ° C under a nitrogen flow. Thereafter, 0.1 part by weight of tetra-n-butylsulfonium bromide as an addition reaction catalyst of a hydroxyl group and an epoxy group was added and an addition polymerization reaction was carried out at 150 占 폚 for 6 hours under a nitrogen flow to obtain a polymer A.

NMR confirmed that the addition polymerization reaction had proceeded and that the polymer A contained a structural unit having a hydroxyl group derived from bisphenol F and an epoxy group of 1,6-hexanediol diglycidyl ether and bisphenol F type epoxy resin bonded to the main chain , And an epoxy group at both ends.

Polymer A obtained by GPC had a weight average molecular weight of 10,000 and a number average molecular weight of 3,500.

Polymer B: epoxy-terminated skeleton phenoxy resin at both ends, "YX6900BH45" manufactured by Mitsubishi Chemical Corporation, weight average molecular weight of 16,000

A thermosetting compound 1 ("EX-201" manufactured by Nagase Chemitex Co., Ltd., solid, thermosetting epoxy compound at 25 캜 was crystallized at -5 캜, washed with hexane, and then hexane was removed by vacuum drying)

A thermosetting compound 2 (solid at 25 캜, a thermosetting epoxy compound, " HP-4032D ", manufactured by DIC Corporation) was crystallized at -5 캜 and washed with hexane and then hexane was removed by vacuum drying.

Thermosetting compound 3 (liquid at 25 占 폚, thermosetting epoxy compound, "1,6-hexanediol glycidyl ether" manufactured by Yokkaichigo Co., Ltd.)

A thermosetting compound 4 (liquid at 25 캜, a thermosetting polythiol compound, "CALENS MT PE1" manufactured by Showa Denko KK)

A thermosetting compound 5 (solid at 25 캜, a thermosetting epoxy compound, "EP-3300" manufactured by ADEKA) was crystallized at -5 캜, washed with hexane, and then hexane was removed by vacuum drying.

A thermosetting compound 6 ("TEPIC-SS" manufactured by Nissan Chemical Industries, Ltd., solid, thermosetting epoxy compound at 25 캜 was crystallized at -5 캜, washed with hexane, and then hexane was removed by vacuum drying)

A thermosetting compound 7 (solid at 25 占 폚, a thermosetting epoxy compound, a product of Asahi Chemical Co., Ltd., "TEP-G" was crystallized at -5 占 폚, washed with hexane, and then hexane was removed by vacuum drying)

Flux ("adipic acid" manufactured by Wako Pure Chemical Industries, Ltd.)

Filler (hydrophobic fumed silica, " Leo seal MT-10 " manufactured by Tokuyama)

Conductive particles 1 (SnBi solder particles, melting point 139 占 폚, "ST-5" manufactured by Mitsui Chemicals, Inc., average particle diameter 5.4 占 퐉)

Conductive particles 2 (SnBi solder particles, melting point 139 占 폚, "DS-10" manufactured by Mitsui Chemicals, Inc., average particle diameter 12 占 퐉)

Conductive particles 3: (resin core solder coated particles, manufactured by the following procedure)

Divinylbenzene resin particles (micropearl SP-207, manufactured by Sekisui Chemical Co., Ltd., average particle diameter 7 mu m) were electroless nickel plated to form a ground nickel plating layer having a thickness of 0.1 mu m on the surface of the resin particles. Subsequently, resin particles having a base nickel plated layer formed thereon were electrolytically copper plated to form a copper layer having a thickness of 1 m. Further, electrolytic plating was performed using an electrolytic plating solution containing tin and bismuth to form a solder layer having a thickness of 1 占 퐉. Thus, a copper layer having a thickness of 1 占 퐉 was formed on the surface of the resin particle, and a solder layer (tin: bismuth = 43 wt%: 57 wt%) having a thickness of 1 占 퐉 was formed on the surface of the copper layer. Particles (average particle diameter 14 mu m, resin core solder coated particles) were produced.

Electroconductive particles 4: Au plating particles ("Au-210" manufactured by Sekisui Chemical Co., Ltd., average particle diameter 10 μm) of divinylbenzene resin particles,

Phenoxy resin ("YP-50S" manufactured by Shin-Nittsu Sumitomo Chemical Co., Ltd.)

(Examples 1 to 10, 12 to 17)

(1) Fabrication of anisotropic conductive paste

The components shown in Tables 1 and 2 were compounded in amounts shown in Tables 1 and 2 to obtain an anisotropic conductive paste.

Further, only the polymer A and the thermosetting compound in the components shown in Tables 1 and 2 were mixed and stirred at 120 DEG C for 1 hour at 60 rpm. Thereafter, the mixture was cooled to room temperature over 3 hours while stirring at 60 rpm. Thereafter, the glass plate was sandwiched, and the particle size of the solid thermosetting compound at 25 占 폚 was observed with an optical microscope. The particle diameters of 100 particles were measured to obtain an average particle diameter.

(2) Fabrication of first connection structure (L / S = 50 탆 / 50 탆)

A glass epoxy substrate (FR-4 substrate) (first connection target member) having a copper electrode pattern (copper electrode thickness 10 mu m) having an L / S of 50 mu m / 50 mu m on its upper surface was prepared. A flexible printed circuit board (second connection target member) having a copper electrode pattern (copper electrode thickness 10 占 퐉) having a L / S of 50 占 퐉 / 50 占 퐉 was prepared.

The overlapping area of the glass epoxy substrate and the flexible printed substrate was 1.5 cm x 4 mm, and the number of electrodes connected was 75 paired.

Anisotropic conductive paste immediately after the preparation was coated and applied on the upper surface of the glass epoxy substrate so as to have a thickness of 50 mu m by screen printing to form an anisotropic conductive paste layer. Subsequently, the flexible printed circuit board was laminated on the upper surface of the anisotropic conductive paste layer such that the electrodes were opposed to each other. At this time, no pressure was applied. The weight of the flexible printed circuit board is applied to the anisotropic conductive paste layer. Thereafter, the solder was melted while heating so that the temperature of the anisotropic conductive paste layer was 185 占 폚, and the anisotropic conductive paste layer was cured at 185 占 폚 to obtain the first connection structure.

(3) Fabrication of second connection structure (L / S = 75 mu m / 75 mu m)

A glass epoxy substrate (FR-4 substrate) (first connection target member) having a copper electrode pattern (copper electrode thickness 10 占 퐉) having an L / S of 75 占 퐉 / 75 占 퐉 on the upper surface was prepared. Further, a flexible printed circuit board (second connection target member) having a copper electrode pattern (copper electrode thickness 10 占 퐉) having L / S of 75 占 퐉 / 75 占 퐉 was prepared.

A second connection structure was obtained in the same manner as in the production of the first connection structure except that the above-mentioned glass epoxy substrate and flexible printed substrate having different L / S were used.

(4) Fabrication of third connection structure (L / S = 100 mu m / 100 mu m)

A glass epoxy substrate (FR-4 substrate) (first connection target member) having a copper electrode pattern (copper electrode thickness of 10 mu m) having an L / S of 100 mu m / 100 mu m on its upper surface was prepared. Further, a flexible printed circuit board (second connection target member) having a copper electrode pattern (copper electrode thickness 10 占 퐉) having L / S of 100 占 퐉 / 100 占 퐉 was prepared.

A third connection structure was obtained in the same manner as in the production of the first connection structure except that the above-mentioned glass epoxy substrate and flexible printed substrate having different L / S were used.

(5) Fabrication of fourth connection structure (L / S = 50 탆 / 50 탆)

(First connection target member) for obtaining the first connection structure and a flexible printed circuit board (second connection target member) for obtaining the first connection structure are placed at 120 DEG C and a humidity of 20 % For 1 hour. A fourth connection structure was obtained in the same manner as in the production of the first connection structure except that the first and second connection target members after storage were used.

(6) Fabrication of fifth connection structure (L / S = 75 占 퐉 / 75 占 퐉)

(First connection target member) for obtaining the second connection structure and a flexible printed circuit board (second connection target member) for obtaining the second connection structure are placed at 120 DEG C and a humidity of 20 % For 1 hour. A fifth connection structure was obtained in the same manner as in the production of the second connection structure except that the first and second connection target members after storage were used.

(7) Fabrication of sixth connection structure (L / S = 100 mu m / 100 mu m)

(First connection object member) for obtaining the third connection structure and a flexible printed circuit board (second connection object member) for obtaining the third connection structure are placed at 120 DEG C and a humidity of 20 % For 1 hour. A sixth connection structure was obtained in the same manner as in the production of the third connection structure except that the first and second connection target members after storage were used.

(Example 11)

(For the first and fourth connection structures), 75 占 퐉 / 75 占 퐉 (for the second and fifth connection structures), 100 占 퐉 / 100 占 퐉 (Size: 30 mm x 30 mm thickness: 0.4 mm) having a rectangular semiconductor chip (thickness 400 mu m) having one side of 5 mm and an electrode facing the same, Second, third, fourth, fifth, and sixth connection structures were obtained.

(Comparative Example 1)

10 parts by weight of a phenoxy resin ("YP-50S" manufactured by Shin-Nittsu Sumitomo Chemical Co., Ltd.) was dissolved in methyl ethyl ketone (MEK) so that the solid content was 50% by weight. The ingredients shown in Table 2 were mixed in the amounts shown in Table 2 below and the total amount of the above solution and stirred at 2000 rpm for 5 minutes using a planetary stirrer and then dried using a bar coater (Polyethylene terephthalate) film so as to have a thickness of 30 mu m. By vacuum drying at room temperature, MEK was removed to obtain an anisotropic conductive film.

The first, second, third, fourth, fifth, and sixth connection structures were obtained in the same manner as in Example 1 except that the anisotropic conductive film was used.

(evaluation)

(1) Viscosity

The viscosity? 1 of the anisotropic conductive paste at 25 占 폚 and 5 rpm was measured using an E-type viscometer (manufactured by Axis KK). The viscosity? 2 at 25 占 폚 and 0.5 rpm of the anisotropic conductive paste was measured using an E-type viscometer (manufactured by Axis KK). The ratio (? 1 /? 2) was obtained from the obtained measurement value.

The viscosity? 1 'of the solder in the conductive particles of the anisotropic conductive paste at a melting point of -5 占 폚 and 5 rpm was measured using an E-type viscometer (manufactured by Axis Industries). The viscosity? 2 'of the solder in the conductive particles of the anisotropic conductive paste at the melting point of -5 占 폚 and 0.5 rpm was measured using an E-type viscometer (manufactured by Axis Industries). The ratio (eta 1 '/ eta 2') was obtained from the obtained measurement value. The ratio? 1 '/? 2' was determined according to the following criteria.

[Criteria of determination of ratio (? 1 '/? 2')]

A: 1 or more and 2 or less

B: It does not correspond to the standard of A

(2) dispersion state

In the anisotropic conductive paste, the dispersion state and the particle diameter of the thermosetting compound solid at 25 占 폚 were observed using an electron microscope. The dispersion state was judged based on the following criteria.

[Criteria for determination of dispersion state]

○ ○: In the conductive paste, the thermosetting compound which is solid at 25 ° C. is dispersed in the form of particles, and the particle diameter of the particle-shaped thermosetting compound is 1 μm or more and 10 μm or less

?: In the conductive paste, the thermosetting compound which is solid at 25 占 폚 is dispersed in the form of particles, and the particle diameter of the thermosetting compound in the particle form is more than 10 占 퐉 and not more than 40 占 퐉

?: In the conductive paste, the thermosetting compound solid at 25 占 폚 is dispersed in a particulate form, and the particle diameter of the particulate thermosetting compound exceeds 40 占 퐉

X: In the conductive paste, the thermosetting compound which is solid at 25 占 폚 is not dispersed in particulate form

(3) Coating workability

In order to obtain the first connection structure, it was evaluated whether or not coating unevenness occurred when the anisotropic conductive paste immediately after fabrication was applied by screen printing to a thickness of 50 mu m. The coating workability was determined based on the following criteria.

[Criteria for determination of application workability]

?: Anisotropic conductive paste does not spread in the unintentional region.

DELTA: Coating can be performed with a thickness deviation of not less than 5 mu m and less than 10 mu m, and anisotropic conductive paste does not spread in unintended areas

X: Thickness deviation of 10 占 퐉 or more occurs after coating, or the anisotropic conductive paste spreads in unintended areas

(4) Spacing between electrodes

The obtained first connection structure was observed by a section to evaluate the distance D1 (distance D1 of the connection portion) between the electrodes at the positions where the upper and lower electrodes face each other.

(5) Arrangement accuracy of conductive particles on electrodes

In the cross section (cross section in the direction shown in Fig. 1) of the obtained first, second and third connection structures, the total of the conductive particles (solder portions, etc.) (%) Of the conductive particles (solder particles or the like) remaining in the cured product. In addition, the average of the areas on the five sections was calculated. The placement accuracy of the conductive particles on the electrode was determined based on the following criteria.

[Criteria for determination of placement accuracy of conductive particles on electrodes]

0: Area A1 is 0%

?: Area A1 is more than 0% and not more than 10%

?: Area A1 is more than 10% but not more than 30%

X: area A1 exceeds 30%

(6) Reliability of conduction between the upper and lower electrodes

In the obtained first, second, third, fourth, fifth, and sixth connection structures (n = 15), the connection resistance between the upper and lower electrodes was measured by the four-terminal method. And the average value of the connection resistance was calculated. From the relationship of voltage = current x resistance, the connection resistance can be obtained by measuring the voltage when a constant current is passed. The conduction reliability was judged to be the criterion below.

[Criteria for reliability of conduction]

○○: Average value of connection resistance is 8.0Ω or less

O: Average value of connection resistance exceeds 8.0? 10.0?

?: Average value of connection resistance exceeds 10.0? 15.0?

X: Average value of connection resistance exceeds 15.0?

(7) Reliability of insulation between adjacent electrodes

In the obtained first, second, third, fourth, fifth, and sixth connection structures (n = 15), after being left in an atmosphere at 85 캜 and 85% humidity for 100 hours, And the resistance value was measured at 25 points. The insulation reliability was determined based on the following criteria.

[Judgment Criteria of Insulation Reliability]

○○: Average value of connection resistance is more than 10 ⁷ Ω

○: Average value of connection resistance is 10 ⁶ Ω or more and less than 10 ⁷ Ω

△: average value of connection resistance is 10 ⁵ Ω or more and less than 10 ⁶ Ω

X: Average value of connection resistance is less than 10 ⁵ Ω

The results are shown in Tables 1 and 2 below.

From the difference between the results of Example 1 and Comparative Example 1 and the difference between the results of Example 11 and Comparative Example 3, it can be seen that, when the second connection target member is a flexible printed circuit board, , It can be seen that the effect of improving the conduction reliability by using the conductive paste of the present invention can be obtained more effectively. Further, in the evaluation of the conduction reliability (results xxx) of Examples 16 and 17, since a plurality of thermosetting compounds which are solid at 25 占 폚 having different melting points are used, Specific values of connection resistance were low. In Examples 16 and 17, the conduction reliability is particularly excellent as compared with the other embodiments.

1, 1X: connection structure
2: first connection object member
2a: first electrode
3: second connection object member
3a: second electrode
4, 4X: connection
4A, 4XA: soldering portion
4B and 4XB:
11: Conductive paste
11A: Solder particles
11B: Thermosetting component
51: conductive particles
51a: outer surface
52: Base particles
52a: outer surface
53:
54: first conductive part
54a: outer surface
55: soldering portion
61: conductive particles
62: soldering portion

Claims (18)

A thermosetting component and a plurality of conductive particles,
Wherein the thermosetting component comprises a thermosetting compound which is solid at 25 DEG C and a thermosetting agent,
Wherein the thermosetting compound solid at 25 占 폚 is dispersed in the form of particles in the conductive paste. The conductive paste according to claim 1, which contains a thermosetting compound which is liquid at 25 占 폚. The conductive paste according to claim 1 or 2, wherein the thermosetting compound solid at 25 占 폚 is a thermosetting epoxy compound solid at 25 占 폚. The method of any one of claims 1 to 3, wherein the thermosetting compound that is solid at 25 占 폚 has a melting point different from that of the first thermosetting compound at 25 占 폚 and a second thermosetting compound having a melting point at 25 占 폚 A conductive paste comprising a second thermosetting compound that is solid. 5. The conductive paste according to any one of claims 1 to 4, wherein the conductive particles comprise solder on a conductive outer surface. The conductive paste according to claim 5, wherein the conductive particles are solder particles. The conductive particle according to claim 5 or 6, wherein the ratio of the viscosity of the solder at -5 占 폚 and 5 rpm to the viscosity at -5 占 폚 and 0.5 rpm of the solder in the conductive particle 1 or more and 2 or less. The conductive paste according to any one of claims 1 to 7, wherein the particulate thermosetting compound has a particle diameter of 1 占 퐉 or more and 40 占 퐉 or less. 9. The conductive paste according to any one of claims 1 to 8, wherein the ratio of the viscosity at 25 DEG C and 5 rpm to the viscosity at 25 DEG C and 0.5 rpm is from 2.5 to 7. 10. The conductive paste according to claim 9, wherein the ratio of the viscosity at 25 DEG C and 5 rpm to the viscosity at 25 DEG C and 0.5 rpm is 4 or more and 7 or less. 11. The conductive paste according to any one of claims 1 to 10, comprising a flux. 12. The conductive paste according to any one of claims 1 to 11, wherein the filler is not contained, or the filler is contained in an amount of 1 wt% or less in 100 wt% of the conductive paste. A method for producing a conductive paste according to any one of claims 1 to 12,
A mixture of a thermosetting component containing a thermosetting compound which is solid at 25 占 폚 and a thermosetting component and a plurality of conductive particles is obtained by mixing the mixture at 25 占 폚 at a temperature not lower than the melting point of the thermosetting compound which is solid at 25 占 폚, To obtain a conductive paste in which the thermosetting compound solid at 25 占 폚 is dispersed in a particulate form by melting the thermosetting compound solid at 25 占 폚 and then solidifying the thermosetting compound at 25 占 폚,
A mixture containing a plurality of conductive particles and a thermosetting component containing a thermosetting compound and a thermosetting agent which are particulate and solid at 25 DEG C and a thermosetting agent at 25 DEG C at a temperature of 25 DEG C, A conductive paste in which a thermosetting compound is dispersed in particles is obtained. A first connection target member having at least one first electrode on its surface,
A second connection target member having at least one second electrode on its surface,
And a connection unit connecting the first connection target member and the second connection target member,
Wherein the connecting portion is formed by the conductive paste according to any one of claims 1 to 12,
Wherein the first electrode and the second electrode are electrically connected by the conductive particles in the connection portion. The connection structure according to claim 14, wherein the second connection target member is a resin film, a flexible printed circuit board, a flexible flat cable, or a rigid flexible substrate. 13. A method of manufacturing a semiconductor device, comprising the steps of: disposing the conductive paste on a surface of a first connection target member having at least one first electrode on a surface thereof using the conductive paste according to any one of claims 1 to 12;
A second connection target member having at least one second electrode on its surface on a surface opposite to the first connection target member side of the conductive paste is arranged so that the first electrode and the second electrode face each other The process,
Heating the conductive paste at a temperature higher than the melting point of the thermosetting compound solid at 25 占 폚 and not lower than the hardening temperature of the thermosetting component to form a connection portion connecting the first connection target member and the second connection target member to the conductive paste And electrically connecting the first electrode and the second electrode by the conductive particles in the connection portion. The method according to claim 16, wherein in the step of disposing the second connection target member and the step of forming the connection part, the weight of the second connection object member is applied to the conductive paste without applying pressure, Gt; The method of manufacturing a connection structure according to claim 16 or 17, wherein the second connection target member is a resin film, a flexible printed substrate, a flexible flat cable, or a rigid flexible substrate.

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