JP6974137B2 - Conductive material, connection structure and method for manufacturing the connection structure - Google Patents

Description

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

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

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

With the anisotropic conductive material, for example, when the electrode of the flexible printed substrate and the electrode of the glass epoxy substrate are electrically connected, the anisotropic conductive material containing the conductive particles is arranged on the glass epoxy substrate. do. Next, the flexible printed substrates are laminated, heated and pressurized. As a result, the anisotropic conductive material is cured, and the electrodes are electrically connected to each other via the conductive particles to obtain a connection structure.

Patent Document 1 below discloses a conductive paste containing a thermosetting component and a plurality of solder particles. The zeta potential on the surface of the solder particles is positive.

Patent Document 2 below discloses a solder paste containing a solder powder, a composite epoxy resin containing a first epoxy resin solid at 25 ° C. and a second epoxy resin liquid at 25 ° C., and a curing agent. ing. The first epoxy resin has a softening point that is 10 ° C. or higher lower than the melting point of the solder powder. The content of the first epoxy resin with respect to 100 parts by weight of the entire composite epoxy resin is 10 parts by weight to 75 parts by weight.

Japanese Unexamined Patent Publication No. 2016-076494 Japanese Unexamined Patent Publication No. 2017-080997

In recent years, mounting has been performed on small electrodes having a narrow electrode width and a narrow space between electrodes. In such a mounting, a line electrode in which a plurality of electrodes are arranged in a line shape may be used.

Conductive materials may be used to connect electronic components such as semiconductor devices that have line electrodes. In the connection of the line electrodes, the conductive material may be applied in a line shape on the line electrodes in order to efficiently carry out the connection between the electrodes. The conductive material applied in a line shape is required to electrically connect the electrodes in the vertical direction to be connected.

In the conventional conductive material, the viscosity of the conductive material is low, and it may be difficult to accurately apply the conductive material in a line shape on the line electrode. Further, when a conventional conductive material having a low melt viscosity is applied on a line electrode, the conductive material may flow excessively due to heating by reflow or the like. If the viscosity of the conductive material is low or the conductive material flows excessively, the line shape cannot be maintained and the conductive material may spread out of the line electrode. When the conductive material spreads out of the line electrode, the solder particles or conductive particles contained in the conductive material are arranged in the region where the line electrode is not formed, and the solder particles or the conductive particles are arranged between the vertical electrodes to be connected. It becomes difficult to efficiently arrange the sex particles. As a result, conventional conductive materials may have low conduction reliability between the electrodes.

Further, when there are a plurality of line electrodes adjacent to each other in the lateral direction, in the conventional conductive material, the solder particles or the conductive particles must not be connected by being arranged in the region where the line electrodes are not formed. Adjacent line electrodes may be electrically connected. As a result, conventional conductive materials may have low insulation reliability between adjacent line electrodes.

An object of the present invention is to provide a conductive material capable of effectively enhancing conduction reliability between electrodes in the vertical direction. Another object of the present invention is to provide a connection structure using the above conductive material and a method for manufacturing the connection structure.

According to a broad aspect of the present invention, it is a conductive material containing a heat-curable component and conductive particles, and the conductive material is placed on a first member with a width of 250 ± 20 μm, a length of 2200 ± 20 μm, and a thickness. The width of the conductive material was set to X1 when the second member was placed on the conductive material and allowed to stand under a pressure condition of 60 Pa, and 60 Pa after standing. When the conductive material reaches 100 ° C. by pressurizing and heating the conductive material under the pressure condition of 1 and the condition of heating from 40 ° C. to 170 ° C. at a heating rate of 1.08 ° C./sec. Provided is a conductive material in which X2 is 1.25 times or less than X1 when the width of the conductive material is X2.

In certain aspects of the conductive material according to the present invention, the conductive particles are solder particles.

In a specific aspect of the conductive material according to the present invention, the minimum value of the melt viscosity of the conductive material in the temperature range of 140 ° C. or lower is 50 Pa · s or more.

In certain aspects of the conductive material according to the present invention, the thermosetting component comprises a thermosetting compound and a thermosetting agent.

In certain aspects of the conductive material according to the present invention, the conductive material comprises a flux.

In certain aspects of the conductive material according to the present invention, the conductive material is a conductive paste.

In a specific aspect of the conductive material according to the present invention, the conductive material is applied and used in a line shape.

According to a broad aspect of the present invention, a first connection target member having a first electrode on the surface, a second connection target member having a second electrode on the surface, and the first connection target member. A connecting portion connecting the second connection target member is provided, the material of the connecting portion is the above-mentioned conductive material, and the first electrode and the second electrode are the conductive material. A connecting structure is provided that is electrically connected by particles.

According to a broad aspect of the present invention, the above-mentioned conductive material is placed on the surface of a first connection target member having a first electrode arranged in a line on the surface along the line of the first electrode. The step of applying in a line shape and the second connection target member having the second electrode arranged in a line shape on the surface opposite to the first connection target member side of the conductive material. By arranging the first electrode and the second electrode so as to face each other and heating the conductive material, the first connection target member and the second connection target member are connected. A method for manufacturing a connection structure, comprising a step of forming the connecting portion with the conductive material and electrically connecting the first electrode and the second electrode with the conductive particles. Is provided.

According to a broad aspect of the present invention, a thermosetting component is provided on the surface of a first connection target member having a first electrode arranged in a line on the surface along the line of the first electrode. A coating step of applying a conductive material containing conductive particles in a line shape, and a second electrode arranged in a line shape on a surface of the conductive material opposite to the first connection target member side. The first connection target member is arranged by arranging the second connection target member having a surface so that the first electrode and the second electrode face each other, and by heating the conductive material. The connection portion connecting the second electrode and the second connection target member is formed of the conductive material, and the first electrode and the second electrode are electrically connected by the conductive particles. The width of the conductive material at the start of heating of the conductive material in the connection step is Xa1, and the temperature of the conductive material reaches 100 ° C. after the start of heating of the conductive material. Provided is a method for manufacturing a connection structure in which Xa2 is 1.25 times or less that of Xa1 when the width of the conductive material is Xa2.

The conductive material according to the present invention contains a thermosetting component and conductive particles. The conductive material according to the present invention is applied in a line on the first member so as to have a width of 250 ± 20 μm, a length of 2200 ± 20 μm, and a thickness of 150 ± 30 μm. Next, when the second member is placed on the conductive material and allowed to stand under a pressure condition of 60 Pa, the width of the conductive material is set to X1, and after standing, the pressure condition is 60 Pa and the temperature rise rate is 1.08. The width of the conductive material when the conductive material reaches 100 ° C. is defined as X2 by pressurizing and heating the conductive material under the condition of heating from 40 ° C. to 170 ° C. at ° C./sec. In the conductive material according to the present invention, the width X2 is 1.25 times or less the width X1. Since the conductive material according to the present invention has the above-mentioned configuration, it is possible to effectively enhance the conduction reliability between the electrodes in the vertical direction. Further, when there are a plurality of line electrodes, the conductive material according to the present invention can effectively enhance the insulation reliability between adjacent line electrodes.

The method for manufacturing a connection structure according to the present invention is to thermally cure the first electrode on the surface of the first connection target member having the first electrodes arranged in a line shape along the line of the first electrode. The present invention comprises a coating step of applying a conductive material containing a sex component and conductive particles in a line shape. The method for manufacturing a connection structure according to the present invention is a second connection having a second electrode arranged in a line on the surface of the conductive material opposite to the first connection target member side. The target member is provided with an arrangement step of arranging the target member so that the first electrode and the second electrode face each other. In the method for manufacturing a connection structure according to the present invention, the conductive material is used to connect the first connection target member and the second connection target member by heating the conductive material. It is provided with a connection step of forming and electrically connecting the first electrode and the second electrode with the conductive particles. In the method for manufacturing a connecting structure according to the present invention, the width of the conductive material at the start of heating of the conductive material in the connection step is set to Xa1, and the temperature of the conductive material reaches 100 ° C. after the heating of the conductive material is started. When the width of the conductive material at the time of reaching is Xa2, Xa2 is set to 1.25 times or less of Xa1. Since the method for manufacturing a connection structure according to the present invention has the above configuration, it is possible to effectively improve the reliability of conduction between the electrodes in the vertical direction. Further, when there are a plurality of line electrodes, the method for manufacturing a connection structure according to the present invention can effectively improve the insulation reliability between adjacent line electrodes.

FIG. 1 is a cross-sectional view schematically showing a connection structure obtained by using the conductive material according to the embodiment of the present invention. 2 (a) to 2 (c) are cross-sectional views for explaining each step of an example of a method of manufacturing a connection structure using the conductive material according to the embodiment of the present invention. FIG. 3 is a cross-sectional view showing a modified example of the connection structure. FIG. 4 is a cross-sectional view showing a first example of conductive particles that can be used as a conductive material. FIG. 5 is a cross-sectional view showing a second example of conductive particles that can be used as a conductive material. FIG. 6 is a cross-sectional view showing a third example of conductive particles that can be used as a conductive material. FIG. 7 is a diagram for explaining electrodes arranged in a line.

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

(Conductive material)
The conductive material according to the present invention contains a thermosetting component and conductive particles. The conductive material according to the present invention is applied in a line on the first member so as to have a width of 250 ± 20 μm, a length of 2200 ± 20 μm, and a thickness of 150 ± 30 μm. Next, when the second member is placed on the conductive material and allowed to stand under a pressure condition of 60 Pa, the width of the conductive material is set to X1, and after standing, the pressure condition is 60 Pa and the temperature rise rate is 1.08. The width of the conductive material when the conductive material reaches 100 ° C. is defined as X2 by pressurizing and heating the conductive material under the condition of heating from 40 ° C. to 170 ° C. at ° C./sec. In the conductive material according to the present invention, the width X2 is 1.25 times or less the width X1. In other words, in the conductive material according to the present invention, the ratio of X2 to X1 is 1.25 or less.

Since the conductive material according to the present invention has the above-mentioned configuration, it is possible to effectively enhance the conduction reliability between the electrodes in the vertical direction. Further, when there are a plurality of line electrodes adjacent to each other in the lateral direction, the conductive material according to the present invention can effectively enhance the conduction reliability and effectively improve the insulation reliability between the adjacent line electrodes. Can be enhanced to.

In the conventional conductive material, the viscosity of the conductive material is low, and it may be difficult to accurately apply the conductive material in a line shape on the line electrode. Further, when a conventional conductive material having a low melt viscosity is applied on a line electrode, the conductive material may flow excessively due to heating by reflow or the like. If the viscosity of the conductive material is low or the conductive material flows excessively, the line shape cannot be maintained and the conductive material spreads out of the line electrode. Therefore, the conductive particles are arranged in the region where the line electrodes are not formed, and the conductive particles cannot be efficiently arranged between the vertical electrodes to be connected, and the conduction between the line electrodes cannot be achieved. It may not be possible to increase the reliability sufficiently. Further, by arranging the conductive particles in the region where the line electrodes are not formed, the adjacent line electrodes in the lateral direction which should not be connected are electrically connected, and the insulation reliability between the adjacent line electrodes is established. It may not be possible to fully enhance the sex.

The present inventors have found that by using a specific conductive material, a line-like shape can be maintained at the time of conductive connection, and line electrodes can be efficiently connected. In the present invention, even in the case of connection between line electrodes, the conduction reliability between the electrodes in the vertical direction to be connected can be effectively increased, and the insulation reliability between adjacent line electrodes can be effectively enhanced. be able to.

In the present invention, the use of a specific conductive material in order to obtain the above-mentioned effects greatly contributes. Examples of the method for obtaining a specific conductive material include the following methods. A method for adjusting physical properties such as viscosity or thixotropic property by adjusting the type and molecular weight of a thermosetting component. A method for adjusting physical properties such as viscosity or thixotropic properties by adjusting the type, surface treatment method, size, blending amount, etc. of conductive particles. A method for adjusting physical properties such as viscosity or thixotropic properties by adjusting the type, size, blending amount, etc. of the filler. A method of adjusting physical properties such as viscosity or thixotropic property by adding a thickener, thixotropic agent, or the like to a conductive material.

Further, in the present invention, it is possible to prevent the positional deviation between the electrodes. In the present invention, when the second connection target member is superposed on the first connection target member on which the conductive material is arranged on the upper surface, the electrodes of the first connection target member and the electrodes of the second connection target member are aligned with each other. Even if the alignment is misaligned, the misalignment can be corrected and the electrodes can be connected to each other (self-alignment effect).

In the conductive material according to the present invention, the ratio of X2 to X1 (X2 / X1) is 1.25 or less. The above ratio (X2 / X1) is preferably 1.20 or less, more preferably 1.10 or less. The lower limit of the above ratio (X2 / X1) is not particularly limited. The above ratio (X2 / X1) may be 1.00 or more. When the ratio (X2 / X1) is equal to or higher than the lower limit and lower than the upper limit, the conduction reliability between the electrodes in the vertical direction can be further effectively increased, and the insulation reliability between the adjacent line electrodes can be improved. It can be enhanced even more effectively.

The temperature at which the conductive material is heated and pressurized is confirmed by the surface temperature of the first electrode.

The width, width X1 and width X2 of the conductive material are obtained by averaging the entire widths. The length of the conductive material is obtained by averaging the total lengths. The thickness of the conductive material is obtained by averaging the total thickness.

In the conductive material according to the present invention, the first member and the second member for obtaining the ratio (X2 / X1) are preferably the following members.

First member: A member having a line electrode having a width of 250 μm, a length of 2200 μm, and a thickness of 150 μm on the surface of the member. One line electrode is an aggregate of electrodes in which a plurality of electrodes having an electrode length of 300 μm are arranged in the length direction of the line electrode with a length between electrodes of 200 μm. The first member is preferably a glass epoxy substrate.

Second member: A member having a line electrode having a width of 250 μm, a length of 2200 μm, and a thickness of 150 μm on the surface of the member body. One line electrode is an aggregate of electrodes in which a plurality of electrodes having an electrode length of 300 μm are arranged in the length direction of the line electrode with a length between electrodes of 200 μm. The second member is preferably a semiconductor chip.

FIG. 7 is a diagram for explaining electrodes arranged in a line.

The member 51 shown in FIG. 7 has electrodes 51a arranged in a line. There are a plurality of electrodes 51a. An aggregate 51A of electrodes in which a plurality of electrodes 51a are lined up corresponds to a line electrode. In FIG. 7, three line electrodes are shown. The line electrode is a portion surrounded by a broken line in FIG. 7. When the line electrode is an aggregate of electrodes, the line electrode has a portion with an electrode and a portion without an electrode. When the line electrode is an aggregate of electrodes and the conductive material is applied along the line electrode, the conductive material is applied on the line electrode including the portion with the electrode and the portion without the electrode. For example, the conductive material is applied in the direction of arrow A in FIG.

From the viewpoint of further effectively enhancing the conduction reliability between the electrodes in the vertical direction and further effectively enhancing the insulation reliability between the adjacent line electrodes, the conductive material may be a conductive paste. preferable.

The viscosity (η25) of the conductive material at 25 ° C. is preferably 50 Pa · s or more, more preferably 100 Pa · s or more, preferably 800 Pa · s or less, and more preferably 600 Pa · s or less. The viscosity (η25) can be appropriately adjusted depending on the type and amount of the compounding component. When the viscosity (η25) is equal to or higher than the lower limit and lower than the upper limit, the conduction reliability between the electrodes in the vertical direction can be further effectively enhanced, and the insulation reliability between the adjacent line electrodes can be further enhanced. Can be effectively enhanced.

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

The viscosity (η100) of the conductive material at 100 ° C. is preferably 100 Pa · s or more, more preferably 150 Pa · s or more, preferably 800 Pa · s or less, and more preferably 650 Pa · s or less. The viscosity (η100) can be appropriately adjusted depending on the type and amount of the compounding component. When the viscosity (η100) is equal to or higher than the lower limit and lower than the upper limit, the conduction reliability between the electrodes in the vertical direction can be further effectively enhanced, and the insulation reliability between the adjacent line electrodes can be further enhanced. Can be effectively enhanced.

The viscosity (η100) can be measured at 100 ° C. and 5 rpm using, for example, an E-type viscometer (“TVE22L” manufactured by Toki Sangyo Co., Ltd.).

The minimum value of the melt viscosity of the conductive material in the temperature range of 140 ° C. or lower is preferably 50 Pa · s or more, more preferably 60 Pa · s or more, preferably 700 Pa · s or less, and more preferably 600 Pa · s or less. be. When the minimum value of the melt viscosity of the conductive material in the temperature range of 140 ° C. or lower is equal to or higher than the lower limit and lower than the upper limit, the conduction reliability between the electrodes in the vertical direction can be further effectively improved, and the conduction reliability between the electrodes in the vertical direction can be further improved. The insulation reliability between the matching line electrodes can be further effectively improved.

The minimum value of the melt viscosity of the conductive material in the temperature range of 70 ° C. or higher and 140 ° C. or lower is preferably 50 Pa · s or more, more preferably 60 Pa · s or more, preferably 700 Pa · s or less, more preferably 600 Pa · s or less.・ It is less than or equal to s. When the minimum value of the melt viscosity of the conductive material in the temperature range of 70 ° C. or higher and 140 ° C. or lower is the lower limit or higher and the upper limit or lower, the conduction reliability between the electrodes in the vertical direction is further effectively enhanced. This makes it possible to further effectively improve the insulation reliability between adjacent line electrodes.

The melt viscosity can be measured by using STRESSTECH (manufactured by REOLOGICA) or the like under the conditions of strain control 1 rad, frequency 1 Hz, heating rate 20 ° C./min, and measurement temperature range 25 to 200 ° C. From the measurement results, the minimum value of the melt viscosity of the conductive material in the temperature range of 140 ° C. or lower or the minimum value of the melt viscosity of the conductive material in the temperature range of 70 ° C. or higher and 140 ° C. or lower can be obtained.

The conductive material can be used as a conductive paste, a conductive film, or the like. The conductive paste is preferably an anisotropic conductive paste, and the conductive film is preferably an anisotropic conductive film. From the viewpoint of more efficiently arranging the solder on the electrodes, the conductive material is preferably a conductive paste. The conductive material is suitably used for electrical connection of electrodes. The conductive material is preferably a circuit connection material. The conductive material is preferably used for electrical connection of line electrodes. The conductive material is preferably used by being applied in a line shape. The conductive material is preferably used by being applied in a line shape on a line electrode. The line electrode is an electrode arranged in a line shape. One electrode may be line-shaped, and the line electrode may be one electrode. A plurality of electrodes may be arranged side by side in a line, and the line electrode may be an aggregate of a plurality of electrodes. There may be a plurality of line electrodes. The plurality of line electrodes may be arranged side by side at intervals.

Hereinafter, each component contained in the conductive material will be described. In the present specification, "(meth) acrylic" means one or both of "acrylic" and "methacrylic", and "(meth) acrylate" means one or both of "acrylate" and "methacrylate". Means.

(Conductive particles)
The conductive material contains conductive particles. The conductive particles electrically connect between the electrodes of the member to be connected. The conductive particles preferably have solder on the outer surface portion of the conductive portion. The conductive particles may be solder particles formed by soldering. Both the central portion and the outer surface of the solder particles are formed of solder. The solder particles are particles in which both the central portion and the outer surface are solder. The conductive particles may have a base material particles and a conductive portion arranged on the surface of the base material particles. In this case, the conductive particles have solder on the outer surface portion of the conductive portion.

The conductive particles preferably have solder on the outer surface portion of the conductive portion. The base particles may be solder particles formed by soldering. The conductive particles may be solder particles in which both the base material particles and the outer surface portion of the conductive portion are solder.

Compared to the case where the above-mentioned solder particles are used, when the conductive particles having the base particles not formed by the solder and the solder portion arranged on the surface of the base particles are used, the case is used. It becomes difficult for conductive particles to collect on the electrodes. Further, since the solder bondability between the conductive particles is low, the conductive particles that have moved on the electrodes tend to move easily to the outside of the electrodes, and the effect of suppressing the displacement between the electrodes tends to be low. Therefore, the conductive particles are preferably solder particles formed by soldering.

Next, a specific example of the conductive particles will be described with reference to the drawings.

FIG. 4 is a cross-sectional view showing a first example of conductive particles that can be used as a conductive material.

The conductive particles 21 shown in FIG. 4 are solder particles. The conductive particles 21 are entirely formed of solder. The conductive particles 21 do not have the base particles in the core and are not core-shell particles. In the conductive particles 21, both the central portion and the outer surface portion of the conductive portion are formed of solder.

FIG. 5 is a cross-sectional view showing a second example of conductive particles that can be used as a conductive material.

The conductive particle 31 shown in FIG. 5 includes a base particle 32 and a conductive portion 33 arranged on the surface of the base particle 32. The conductive portion 33 covers the surface of the base particle 32. The conductive particles 31 are coated particles in which the surface of the base particles 32 is coated with the conductive portion 33.

The conductive portion 33 has a second conductive portion 33A and a solder portion 33B (first conductive portion). The conductive particle 31 includes a second conductive portion 33A between the base particle 32 and the solder portion 33B. Therefore, the conductive particles 31 include the base particles 32, the second conductive portion 33A arranged on the surface of the base particles 32, and the solder portion 33B arranged on the outer surface of the second conductive portion 33A. And prepare.

FIG. 6 is a cross-sectional view showing a third example of conductive particles that can be used as a conductive material.

The conductive portion 33 of the conductive particles 31 in FIG. 5 has a two-layer structure. The conductive particles 41 shown in FIG. 6 have a solder portion 42 as a single-layer conductive portion. The conductive particles 41 include a base particle 32 and a solder portion 42 arranged on the surface of the base particle 32.

Hereinafter, other details of the conductive particles will be described.

Base particle:
Examples of the base particles include resin particles, inorganic particles excluding metal particles, organic-inorganic hybrid particles, and metal particles. The base particles are preferably base particles excluding metal particles, and more preferably resin particles, inorganic particles excluding metal particles, or organic-inorganic hybrid particles. The base particle may be a core-shell particle having a core and a shell arranged on the surface of the core. The core may be an organic core and the shell may be an inorganic shell.

The base particles are more preferably resin particles or organic-inorganic hybrid particles, and may be resin particles or organic-inorganic hybrid particles. The use of these preferred substrate particles provides more suitable conductive particles for electrical connection between the electrodes.

When connecting the electrodes using the conductive particles, the conductive particles are placed between the electrodes and then crimped to compress the conductive particles. When the base particle is a resin particle or an organic-inorganic hybrid particle, the conductive particle is easily deformed at the time of crimping, and the contact area between the conductive particle and the electrode becomes large. Therefore, the continuity reliability between the electrodes is further improved.

Various resins are preferably used as the material for the resin particles. Examples of the material of the resin particles include polyolefin resins such as polyethylene, polypropylene, polystyrene, polyvinyl chloride, polyvinylidene chloride, polyisobutylene and polybutadiene; acrylic resins such as polymethylmethacrylate and polymethylacrylate; polyalkylene terephthalate and polycarbonate. , Polyamide, phenol formaldehyde resin, melamine formaldehyde resin, benzoguanamine formaldehyde resin, urea formaldehyde resin, phenol resin, melamine resin, benzoguanamine resin, urea resin, epoxy resin, unsaturated polyester resin, saturated polyester resin, polysulfone, polyphenylene oxide, polyacetal, Polymerization of one or more types of polyimides, polyamideimides, polyether ether ketones, polyether sulfones, divinylbenzene polymers, divinylbenzene-based copolymers, and various polymerizable monomers having ethylenically unsaturated groups. Examples thereof include a polymer obtained by subjecting the mixture. Examples of the divinylbenzene-based copolymer include a divinylbenzene-styrene copolymer and a divinylbenzene- (meth) acrylic acid ester copolymer.

Since resin particles having arbitrary compressive properties suitable for conductive particles can be designed and synthesized, and the hardness of the substrate particles can be easily controlled within a suitable range, the material of the resin particles is not ethylenically. It is preferably a polymer obtained by polymerizing one or more polymerizable monomers having a plurality of saturated groups.

When the resin particles are obtained by polymerizing a polymerizable monomer having an ethylenically unsaturated group, the polymerizable monomer having an ethylenically unsaturated group may be a non-crosslinkable monomer. Examples thereof include crosslinkable monomers.

Examples of the non-crosslinkable monomer include styrene-based monomers such as styrene and α-methylstyrene; carboxyl group-containing monomers such as (meth) acrylic acid, maleic acid, and maleic anhydride; and methyl ( Meta) acrylate, ethyl (meth) acrylate, propyl (meth) acrylate, butyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, lauryl (meth) acrylate, cetyl (meth) acrylate, stearyl (meth) acrylate, cyclohexyl (meth) Alkyl (meth) acrylate compounds such as meta) acrylate and isobornyl (meth) acrylate; oxygen atoms such as 2-hydroxyethyl (meth) acrylate, glycerol (meth) acrylate, polyoxyethylene (meth) acrylate and glycidyl (meth) acrylate. Containing (meth) acrylate compound; nitrile-containing monomer such as (meth) acrylonitrile; acid vinyl ester compound such as vinyl acetate, vinyl butyrate, vinyl laurate, vinyl stearate; unsaturated such as ethylene, propylene, isoprene, and butadiene. Hydrocarbons; examples thereof include halogen-containing monomers such as trifluoromethyl (meth) acrylate, pentafluoroethyl (meth) acrylate, vinyl chloride, vinyl fluoride, and chlorstyrene.

Examples of the crosslinkable monomer include tetramethylol methanetetra (meth) acrylate, tetramethylol methanetri (meth) acrylate, tetramethylol methanedi (meth) acrylate, trimethylol propanetri (meth) acrylate, and dipenta. Elythritol hexa (meth) acrylate, dipentaerythritol penta (meth) acrylate, glycerol tri (meth) acrylate, glycerol di (meth) acrylate, (poly) ethylene glycol di (meth) acrylate, (poly) propylene glycol di (meth) Polyfunctional (meth) acrylate compounds such as acrylates, (poly) tetramethylene glycol di (meth) acrylates, 1,4-butanediol di (meth) acrylates; triallyl (iso) cyanurate, triallyl trimellitate, divinylbenzene, Examples thereof include silane-containing monomers such as diallyl phthalate, diallyl acrylamide, diallyl ether, γ- (meth) acryloxypropyltrimethoxysilane, trimethoxysilylstyrene, and vinyltrimethoxysilane.

The resin particles can be obtained by polymerizing the polymerizable monomer having an ethylenically unsaturated group by a known method. Examples of this method include a method of suspension polymerization in the presence of a radical polymerization initiator, and a method of swelling and polymerizing a monomer together with a radical polymerization initiator using non-crosslinked seed particles.

When the base particle is an inorganic particle other than the metal particle or an organic-inorganic hybrid particle, examples of the inorganic substance as the material of the base particle include silica, alumina, barium titanate, zirconia, and carbon black. It is preferable that the inorganic substance is not a metal. The particles formed of the silica are not particularly limited, but for example, after hydrolyzing a silicon compound having two or more hydrolyzable alkoxysilyl groups to form crosslinked polymer particles, firing is performed as necessary. Examples include particles obtained by doing so. Examples of the organic-inorganic hybrid particles include organic-inorganic hybrid particles formed of a crosslinked alkoxysilyl polymer and an acrylic resin.

The organic-inorganic hybrid particles are preferably core-shell type organic-inorganic hybrid particles having a core and a shell arranged on the surface of the core. It is preferable that the core is an organic core. It is preferable that the shell is an inorganic shell. From the viewpoint of further effectively lowering the connection resistance between the electrodes, the base particle is preferably an organic-inorganic hybrid particle having an organic core and an inorganic shell arranged on the surface of the organic core. ..

Examples of the material of the organic core include the material of the resin particles described above.

Examples of the material of the inorganic shell include the inorganic substances mentioned as the material of the base particles described above. The material of the inorganic shell is preferably silica. The inorganic shell is preferably formed by forming a metal alkoxide into a shell-like material by a sol-gel method on the surface of the core and then firing the shell-like material. The metal alkoxide is preferably a silane alkoxide. The inorganic shell is preferably formed of silane alkoxide.

When the base material particles are metal particles, examples of the metal as the material of the metal particles include silver, copper, nickel, silicon, gold, and titanium.

The particle size of the base particles is preferably 0.5 μm or more, more preferably 1 μm or more, still more preferably 3 μm or more, preferably 100 μm or less, more preferably 60 μm or less, still more preferably 50 μm or less. When the particle size of the base particles is equal to or larger than the above lower limit, the contact area between the conductive particles and the electrodes becomes large, so that the conduction reliability between the electrodes becomes even higher and the particles are connected via the conductive particles. The connection resistance between the electrodes can be reduced even more effectively. Further, when the conductive portion is formed on the surface of the base particles, it becomes difficult to aggregate, and it becomes difficult to form the aggregated conductive particles. When the particle size of the base particles is not more than the above upper limit, the conductive particles are easily sufficiently compressed, and the connection resistance between the electrodes connected via the conductive particles can be further effectively lowered. can.

It is particularly preferable that the particle size of the base particles is 5 μm or more and 40 μm or less. When the particle size of the base particles is within the range of 5 μm or more and 40 μm or less, the distance between the electrodes can be made smaller, and even if the thickness of the conductive portion is increased, small conductive particles can be obtained. be able to.

The particle size of the base particles indicates the diameter when the base particles are spherical, and indicates the maximum diameter when the base particles are not spherical.

The particle size of the base particles is preferably an average particle size, and preferably a number average particle size. The particle size of the base particles is determined by using a particle size distribution measuring device or the like. The particle size of the base particles is preferably determined by observing 50 arbitrary base particles with an electron microscope or an optical microscope and calculating an average value. When measuring the particle size of the base particles in the conductive particles, for example, the measurement can be performed as follows.

An embedded resin for conducting a conductive particle inspection is prepared by adding and dispersing the conductive particles to "Technobit 4000" manufactured by Kulzer so that the content of the conductive particles is 30% by weight. A cross section of the conductive particles is cut out using an ion milling device (“IM4000” manufactured by Hitachi High-Technologies Corporation) so as to pass near the center of the conductive particles dispersed in the embedded resin for inspection. Then, using a field emission scanning electron microscope (FE-SEM), the image magnification is set to 25,000 times, 50 conductive particles are randomly selected, and the substrate particles of each conductive particle are observed. do. The particle size of the base particle in each conductive particle is measured, and they are arithmetically averaged to obtain the particle size of the base particle.

Conductive part:
The method of forming the conductive portion on the surface of the base material particles and the method of forming the solder portion on the surface of the base material particles or on the surface of the second conductive portion are not particularly limited. Examples of the method for forming the conductive portion and the solder portion include a method by electroplating, a method by electroplating, a method by physical collision, a method by mechanochemical reaction, a method by physical vapor deposition or physical adsorption, and the like. Further, a method of coating the surface of the base particle with a metal powder or a paste containing the metal powder and the binder and the like can be mentioned. The method for forming the conductive portion and the solder portion is preferably a method by electroless plating, electroplating or physical collision. Examples of the method by physical vapor deposition include vacuum deposition, ion plating, and ion sputtering. Further, in the above-mentioned physical collision method, for example, a seater composer (manufactured by Tokuju Kosakusho Co., Ltd.) or the like is used.

The melting point of the base particles is preferably higher than the melting points of the conductive portion and the solder portion. The melting point of the base particles preferably exceeds 160 ° C., more preferably exceeds 300 ° C., further preferably exceeds 400 ° C., and particularly preferably exceeds 450 ° C. The melting point of the base particles may be less than 400 ° C. The melting point of the base particles may be 160 ° C. or lower. The softening point of the base particles is preferably 260 ° C. or higher. The softening point of the base particles may be less than 260 ° C.

The conductive particles may have a single-layer solder portion. The conductive particles may have a plurality of layers of conductive portions (solder portion, second conductive portion). That is, in the conductive particles, two or more conductive portions may be laminated. When the conductive portion has two or more layers, it is preferable that the conductive particles have solder on the outer surface portion of the conductive portion.

The solder is preferably a metal having a melting point of 450 ° C. or lower (low melting point metal). The solder portion is preferably a metal layer (low melting point metal layer) having a melting point of 450 ° C. or lower. The low melting point metal layer is a layer containing a low melting point metal. The solder in the conductive particles is preferably metal particles having a melting point of 450 ° C. or lower (low melting point metal particles). The solder particles are preferably low melting point metal particles. 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 ° C. or lower. The melting point of the low melting point metal is preferably 300 ° C. or lower, more preferably 160 ° C. or lower. The solder particles are preferably low melting point solder having a melting point of less than 150 ° C.

The melting point of the low melting point metal and the melting point of the solder particles can be determined by differential scanning calorimetry (DSC). Examples of the differential scanning calorimetry (DSC) device include "EXSTAR DSC7020" manufactured by SII.

Further, the solder in the conductive particles preferably contains tin. The tin content is preferably 30% by weight or more, more preferably 40% by weight or more, still more preferably 40% by weight or more, in 100% by weight of the metal contained in the solder portion and 100% by weight of the metal contained in the solder in the conductive particles. Is 70% by weight or more, particularly preferably 90% by weight or more. When the content of tin contained in the solder in the solder portion and the conductive particles is at least the above lower limit, the conduction reliability between the conductive particles and the electrode is further increased.

The tin content may be determined using a high frequency inductively coupled plasma emission spectrophotometer (“ICP-AES” manufactured by Horiba, Ltd.) or a fluorescent X-ray analyzer (“EDX-800HS” manufactured by Shimadzu Corporation). Can be measured.

By using the conductive particles having the solder on the outer surface portion of the conductive portion, the solder melts and is bonded to the electrodes, and the solder conducts the electrodes. For example, the solder and the electrode are likely to make surface contact rather than point contact, so that the connection resistance is low. Further, by using the conductive particles having the solder on the outer surface portion of the conductive portion, the bonding strength between the solder and the electrode is increased, and as a result, the peeling between the solder and the electrode is more difficult to occur, and the conduction reliability is effective. Will be high.

The solder portion and the low melting point metal constituting the solder are not particularly limited. The low melting point metal is preferably tin or an alloy containing tin. Examples of the alloy include tin-silver alloy, tin-copper alloy, tin-silver-copper alloy, tin-bismuth alloy, tin-zinc alloy, tin-indium alloy and the like. The low melting point metal is preferably tin, tin-silver alloy, tin-silver-copper alloy, tin-bismuth alloy, or tin-indium alloy because of its excellent wettability to the electrode. More preferably, it is a tin-bismuth alloy or a tin-indium alloy.

The material constituting the solder (solder portion) is preferably a filler material having a liquidus line of 450 ° C. or lower based on JIS Z3001: welding terminology. Examples of the composition of the solder include a metal composition containing zinc, gold, silver, lead, copper, tin, bismuth, indium and the like. A tin-indium system (117 ° C. eutectic) or a tin-bismuth system (139 ° C. eutectic), which has a low melting point and is lead-free, is preferable. That is, the solder preferably does not contain lead, and is preferably a solder containing tin and indium, or a solder containing tin and bismuth.

In order to further increase the bonding strength between the solder and the electrode in the solder part or the conductive particles, the solder in the conductive particles is nickel, copper, antimony, aluminum, zinc, iron, gold, titanium, phosphorus, germanium, tellurium. , Cobalt, bismuth, manganese, chromium, molybdenum, palladium and the like may be contained. Further, from the viewpoint of further increasing the bonding strength between the solder and the electrode in the solder portion or the conductive particles, the solder in the conductive particles preferably contains nickel, copper, antimony, aluminum or zinc. From the viewpoint of further increasing the bonding strength between the solder and the electrode in the solder portion or the conductive particles, the content of these metals for increasing the bonding strength is preferably 0 in 100% by weight of the solder in the conductive particles. It is .0001% by weight or more, preferably 1% by weight or less.

The melting point of the second conductive portion is preferably higher than the melting point of the solder portion. The melting point of the second conductive portion preferably exceeds 160 ° C, more preferably exceeds 300 ° C, further preferably exceeds 400 ° C, further preferably exceeds 450 ° C, and particularly preferably exceeds 500 ° C. Most preferably, it exceeds 600 ° C. Since the solder portion has a low melting point, it melts at the time of conductive connection. It is preferable that the second conductive portion does not melt at the time of conductive connection. The conductive particles are preferably used by melting the solder, preferably by melting the solder portion, and are used by melting the solder portion and not melting the second conductive portion. It is preferable to be Since the melting point of the second conductive portion is higher than the melting point of the solder portion, it is possible to melt only the solder portion without melting the second conductive portion at the time of conductive connection.

The absolute value of the difference between the melting point of the solder portion and the melting point of the second conductive portion exceeds 0 ° C., preferably 5 ° C. or higher, more preferably 10 ° C. or higher, still more preferably 30 ° C. or higher, particularly preferably. Is 50 ° C. or higher, most preferably 100 ° C. or higher.

The second conductive portion preferably contains a metal. The metal constituting the second conductive portion is not particularly limited. Examples of the metal include gold, silver, copper, platinum, palladium, zinc, lead, aluminum, cobalt, indium, nickel, chromium, titanium, antimony, bismuth, germanium and cadmium, and alloys thereof. Further, tin-doped indium oxide (ITO) may be used as the metal. Only one kind of the above metal may be used, or two or more kinds thereof may be used in combination.

The second conductive portion is preferably a nickel layer, a palladium layer, a copper layer or a gold layer, more preferably a nickel layer, a gold layer or a copper layer, and further preferably a copper layer. The conductive particles preferably have a nickel layer, a palladium layer, a copper layer or a gold layer, more preferably have a nickel layer, a gold layer or a copper layer, and even more preferably have a copper layer. By using the conductive particles having these preferable conductive portions for the connection between the electrodes, the connection resistance between the electrodes is further lowered. Further, a solder portion can be more easily formed on the surface of these preferable conductive portions.

The thickness of the solder portion is preferably 0.005 μm or more, more preferably 0.01 μm or more, preferably 10 μm or less, more preferably 1 μm or less, still more preferably 0.3 μm or less. When the thickness of the solder portion is not less than the above lower limit and not more than the above upper limit, sufficient conductivity can be obtained, the conductive particles do not become too hard, and the conductive particles are sufficiently deformed at the time of connection between the electrodes. do.

The particle size of the conductive particles is preferably 0.5 μm or more, more preferably 1 μm or more, still more preferably 3 μm or more, preferably 100 μm or less, more preferably 60 μm or less, still more preferably 50 μm or less, and particularly preferably. It is 40 μm or less. When the particle size of the conductive particles is equal to or greater than the above lower limit and equal to or less than the above upper limit, the solder in the conductive particles can be arranged more efficiently on the electrodes, and more solder in the conductive particles is formed between the electrodes. It is easy to arrange and the continuity reliability is further improved.

The particle size of the conductive particles is preferably an average particle size, more preferably a number average particle size. The average particle size of the conductive particles can be obtained, for example, by observing 50 arbitrary conductive particles with an electron microscope or an optical microscope, calculating the average value, or performing laser diffraction type particle size distribution measurement.

The CV value of the particle size of the conductive particles is preferably 5% or more, more preferably 10% or more, preferably 40% or less, and more preferably 30% or less. When the CV value of the particle size is at least the above lower limit and at least the above upper limit, the solder can be arranged more efficiently on the electrode. However, the CV value of the particle size of the conductive particles may be less than 5%.

The CV value (coefficient of variation) of the particle size of the conductive particles can be measured as follows.

CV value (%) = (ρ / Dn) × 100

ρ: Standard deviation of particle size of conductive particles Dn: Average value of particle size of conductive particles

The shape of the conductive particles is not particularly limited. The shape of the conductive particles may be spherical or may be a shape other than a spherical shape such as a flat shape.

The content of the conductive particles in 100% by weight of the conductive material is preferably 1% by weight or more, more preferably 2% by weight or more, still more preferably 10% by weight or more, particularly preferably 20% by weight or more, and most preferably. It is 30% by weight or more, preferably 80% by weight or less, more preferably 60% by weight or less, still more preferably 50% by weight or less. When the content of the conductive particles is not less than the above lower limit and not more than the above upper limit, the conductive particles can be arranged more efficiently on the electrodes, and more conductive particles can be arranged between the electrodes. It is easy and the continuity reliability is further improved. From the viewpoint of further enhancing the conduction reliability, it is preferable that the content of the conductive particles is large.

(Thermosetting component)
The conductive material contains a thermosetting component. The thermosetting component may contain a thermosetting compound or may contain a thermosetting agent. In order to cure the conductive material more satisfactorily, the thermosetting component preferably contains a thermosetting compound and a thermosetting agent. In order to cure the conductive material more satisfactorily, the thermosetting component preferably contains a curing accelerator.

(Thermosetting component: Thermosetting compound)
The thermosetting compound is not particularly limited. Examples of the thermosetting compound include oxetane compounds, epoxy compounds, episulfide compounds, (meth) acrylic compounds, phenol compounds, amino compounds, unsaturated polyester compounds, polyurethane compounds, silicone compounds and polyimide compounds. From the viewpoint of further improving the curability and viscosity of the conductive material, from the viewpoint of further effectively enhancing the conduction reliability between the electrodes in the vertical direction, and further effectively enhancing the insulation reliability between the adjacent line electrodes. From the viewpoint, an epoxy compound or an episulfide compound is preferable, and an epoxy compound is more preferable.

The thermosetting compound preferably contains an epoxy compound. Only one kind of the thermosetting compound may be used, or two or more kinds may be used in combination.

The epoxy compound is a compound having at least one epoxy group. Examples of the epoxy compound include bisphenol A type epoxy compound, bisphenol F type epoxy compound, bisphenol S type epoxy compound, phenol novolac type epoxy compound, biphenyl type epoxy compound, biphenyl novolac type epoxy compound, biphenol type epoxy compound, and naphthalene type epoxy compound. , Fluolene type epoxy compound, phenol aralkyl type epoxy compound, naphthol aralkyl type epoxy compound, dicyclopentadiene type epoxy compound, anthracene type epoxy compound, adamantan skeleton epoxy compound, tricyclodecane skeleton epoxy compound, naphthylene ether type Examples thereof include epoxy compounds and epoxy compounds having a triazine nucleus as a skeleton. Only one kind of the epoxy compound may be used, or two or more kinds may be used in combination.

The epoxy compound is liquid or solid at room temperature (23 ° C.), and when the epoxy compound is solid at room temperature, the melting temperature of the epoxy compound is equal to or lower than the melting point of the conductive portion of the conductive particles. Is preferable.

The thermosetting compound contains an epoxy compound from the viewpoint of further effectively enhancing the conduction reliability between the electrodes in the vertical direction and further effectively enhancing the insulation reliability between the adjacent line electrodes. Is preferable.

From the viewpoint of further effectively enhancing the conduction reliability between the electrodes in the vertical direction and further effectively enhancing the insulation reliability between the adjacent line electrodes, the epoxy compound is a dicyclopentadiene type epoxy compound or It is preferably a naphthalene type epoxy compound.

From the viewpoint of further effectively enhancing the heat resistance of the cured product, the thermosetting compound preferably contains a thermosetting compound having an isocyanulu skeleton.

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

The content of the thermosetting compound in 100% by weight of the conductive material is preferably 20% by weight or more, more preferably 40% by weight or more, still more preferably 50% by weight or more, and preferably 99% by weight or less. It is preferably 98% by weight or less, more preferably 90% by weight or less, and particularly preferably 80% by weight or less. When the content of the thermosetting compound is not less than the above lower limit and not more than the above upper limit, the conductive particles can be arranged more efficiently on the electrode. When the content of the thermosetting compound is not less than the above lower limit and not more than the above upper limit, the conduction reliability between the electrodes in the vertical direction can be further effectively increased, and the insulation reliability between the adjacent line electrodes can be further improved. Can be enhanced even more effectively. From the viewpoint of further effectively enhancing the impact resistance, it is preferable that the content of the thermosetting compound is large.

The content of the epoxy compound in 100% by weight of the conductive material is preferably 20% by weight or more, more preferably 40% by weight or more, still more preferably 50% by weight or more, preferably 99% by weight or less, more preferably 99% by weight or less. It is 98% by weight or less, more preferably 90% by weight or less, and particularly preferably 80% by weight or less. When the content of the epoxy compound is not less than the above lower limit and not more than the above upper limit, the conductive particles can be arranged more efficiently on the electrode. When the content of the epoxy compound is not less than the above lower limit and not more than the above upper limit, the conduction reliability between the electrodes in the vertical direction can be further effectively increased, and the insulation reliability between the adjacent line electrodes can be further improved. It can be enhanced more effectively. From the viewpoint of further enhancing the impact resistance, it is preferable that the content of the epoxy compound is large.

(Thermosetting component: Thermosetting agent)
The thermosetting agent is not particularly limited. The thermosetting agent heat-cures the thermosetting compound. Examples of the heat curing agent include thiol curing agents such as imidazole curing agents, amine curing agents, phenol curing agents, and polythiol curing agents, acid anhydride curing agents, thermal cation initiators (thermal cation curing agents), and thermal radical generators. Can be mentioned. Only one type of the thermosetting agent may be used, or two or more types may be used in combination.

From the viewpoint of enabling the conductive material to be cured more quickly at a low temperature, the thermosetting agent is preferably an imidazole curing agent, a thiol curing agent, or an amine curing agent. Further, from the viewpoint of enhancing the storage stability when the thermosetting compound and the thermosetting agent are mixed, the thermosetting agent is preferably a latent curing agent. The latent curing agent is preferably a latent imidazole curing agent, a latent thiol curing agent or a latent amine curing agent. The thermosetting agent may be coated with a polymer substance such as a polyurethane resin or a polyester resin.

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

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

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

The acid anhydride curing agent is not particularly limited, and any acid anhydride used as a curing agent for a thermosetting compound such as an epoxy compound can be widely used. Examples of the acid anhydride curing agent include phthalic anhydride, tetrahydrophthalic anhydride, trialkyltetrahydrochloride phthalic acid, hexahydrohydride phthalic acid, methylhexahydrohydride phthalic acid, methyltetrahydrohydride phthalic acid, and methylbutenyltetrahydrochloride phthalic acid. , Anhydride of phthalic acid derivative, maleic anhydride, nadic acid anhydride, methylnadic acid anhydride, glutaric anhydride, succinic anhydride, glycerinbis anhydrous trimellitic acid monoacetate, ethylene glycol bis anhydrous trimellitic acid, etc. Acid anhydride curing agent, trifunctional acid anhydride curing agent such as trimellitic anhydride, and pyromellitic anhydride, benzophenonetetracarboxylic acid anhydride, methylcyclohexenetetracarboxylic acid anhydride, polyazelineic acid anhydride, etc. Examples thereof include an acid anhydride curing agent having four or more functions.

The thermal cation initiator is not particularly limited. Examples of the thermal cation initiator include an iodonium-based cation curing agent, an oxonium-based cation curing agent, and a sulfonium-based cation curing agent. Examples of the iodine-based cationic curing agent include bis (4-tert-butylphenyl) iodinenium hexafluorophosphate and the like. Examples of the oxonium-based cationic curing agent include trimethyloxonium tetrafluoroborate. Examples of the sulfonium-based cationic curing agent include tri-p-tolylsulfonium hexafluorophosphate.

The thermal radical generator is not particularly limited. Examples of the thermal radical generator include azo compounds and organic peroxides. Examples of the azo compound include azobisisobutyronitrile (AIBN) and the like. Examples of the organic peroxide include di-tert-butyl peroxide and methyl ethyl ketone peroxide.

The reaction start temperature of the thermosetting agent is preferably 50 ° C. or higher, more preferably 70 ° C. or higher, still more preferably 80 ° C. or higher, preferably 250 ° C. or lower, more preferably 200 ° C. or lower, still more preferably 150 ° C. or higher. Below, it is particularly preferably 140 ° C. or lower. When the reaction start temperature of the thermosetting agent is equal to or higher than the lower limit and lower than the upper limit, the conductive particles are more efficiently arranged on the electrode. The reaction start temperature of the thermosetting agent is particularly preferably 80 ° C. or higher and 140 ° C. or lower.

From the viewpoint of more efficiently arranging the conductive particles on the electrode, the reaction start temperature of the thermal curing agent is preferably higher than the melting point of the solder in the conductive particles, and more preferably 5 ° C. or higher. It is preferable, and it is more preferable that the temperature is 10 ° C. or higher.

The reaction start temperature of the thermosetting agent means the temperature at which the exothermic peak starts to rise in the DSC.

The content of the thermosetting agent is not particularly limited. With respect to 100 parts by weight of the thermosetting compound, the content of the thermosetting agent is preferably 0.01 parts by weight or more, more preferably 1 part by weight or more, preferably 200 parts by weight or less, and more preferably. It is 100 parts by weight or less, more preferably 75 parts by weight or less. When the content of the thermosetting agent is at least the above lower limit, it is easy to sufficiently cure the conductive material. When the content of the thermosetting agent is not more than the above upper limit, it becomes difficult for the surplus thermosetting agent that was not involved in the curing to remain after curing, and the heat resistance of the cured product is further increased.

(Thermosetting component: Curing accelerator)
The conductive material may contain a curing accelerator. The curing accelerator is not particularly limited. The curing accelerator preferably acts as a curing catalyst in the reaction between the thermosetting compound and the thermosetting agent. The curing accelerator preferably acts as a curing catalyst in the reaction with the thermosetting compound. As the curing accelerator, only one kind may be used, or two or more kinds may be used in combination.

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

The phosphonium salt is not particularly limited. Examples of the phosphonium salt include tetranormal butyl phosphonium bromide, tetranormal butyl phosphonium O-O diethyl dithiophosphate, methyl tributyl phosphonium dimethyl phosphate, tetranormal butyl phosphonium benzotriazole, tetranormal butyl phosphonium tetrafluoroborate, and tetranormal butyl. Examples thereof include phosphonium tetraphenylborate.

The content of the curing accelerator is appropriately selected so that the thermosetting compound can be cured well. The content of the curing accelerator with respect to 100 parts by weight of the thermosetting compound is preferably 0.5 parts by weight or more, more preferably 3 parts by weight or more, preferably 8 parts by weight or less, and more preferably 6 parts by weight. It is as follows. When the content of the curing accelerator is at least the above lower limit and at least the above upper limit, the thermosetting compound can be satisfactorily cured.

(flux)
The conductive material may contain a flux. By using the flux, the conductive particles can be arranged more efficiently on the electrode. The above flux is not particularly limited. As the flux, a flux generally used for solder joining or the like can be used.

The flux includes zinc chloride, a mixture of zinc chloride and an inorganic halide, a mixture of zinc chloride and an inorganic acid, a molten salt, phosphoric acid, a derivative of phosphoric acid, an organic halide, a hydrazine, an amine compound, an organic acid and the like. Examples include pine fat. Only one kind of the above flux may be used, or two or more kinds of the flux may be used in combination.

Examples of the molten salt include ammonium chloride. Examples of the organic acid include lactic acid, citric acid, stearic acid, glutamic acid and glutaric acid. Examples of the pine fat include activated pine fat and deactivated pine fat. The flux is preferably an organic acid having two or more carboxyl groups or pine fat. The flux may be an organic acid having two or more carboxyl groups, or may be pine fat. The use of organic acids and pine fats having two or more carboxyl groups further enhances the reliability of conduction between the electrodes.

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

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

The above-mentioned pine fat is a rosin containing abietic acid as a main component. Examples of the rosins include abietic acid and acrylic-modified rosins. The flux is preferably rosins, more preferably abietic acid. By using this preferable flux, the conduction reliability between the electrodes is further increased.

The active temperature (melting point) of the flux is preferably 50 ° C. or higher, more preferably 70 ° C. or higher, still more preferably 80 ° C. or higher, preferably 200 ° C. or lower, more preferably 190 ° C. or lower, still more preferably 160 ° C. or higher. ° C. or lower, more preferably 150 ° C. or lower, even more preferably 140 ° C. or lower. When the active temperature of the flux is not less than the lower limit and not more than the upper limit, the flux effect is exhibited more effectively and the conductive particles are arranged more efficiently on the electrode. The active temperature (melting point) of the flux is preferably 80 ° C. or higher and 190 ° C. or lower. The active temperature (melting point) of the flux is particularly preferably 80 ° C. or higher and 140 ° C. or lower.

The active temperature (melting point) of the flux is 80 ° C. or higher and 190 ° C. or lower. 104 ° C.), dicarboxylic acids such as suberic acid (melting point 142 ° C.), benzoic acid (melting point 122 ° C.), malic acid (melting point 130 ° C.) and the like.

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

From the viewpoint of more efficiently arranging the conductive particles on the electrode, the melting point of the flux is preferably higher than the melting point of the solder in the conductive particle particles, and more preferably 5 ° C. or higher. It is more preferable that the temperature is higher than ° C.

From the viewpoint of more efficiently arranging the conductive particles on the electrode, the melting point of the flux is preferably higher than the reaction start temperature of the thermosetting agent, more preferably 5 ° C. or higher, and more preferably 10 ° C. It is more preferable that the value is higher than that.

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

Since the melting point of the flux is higher than the melting point of the solder in the conductive particles, the conductive particles can be efficiently aggregated on the electrode portion. This is because, when heat is applied at the time of joining, when the electrode formed on the connection target member and the connection target member portion around the electrode are compared, the thermal conductivity of the electrode portion is that of the connection target member portion around the electrode. Because it is higher than the thermal conductivity, the temperature rise of the electrode portion is fast. At the stage where the melting point of the solder in the conductive particles is exceeded, the solder portion in the conductive particles is melted, but the oxide film formed on the surface is not removed because it has not reached the melting point (active temperature) of the flux. In this state, since the temperature of the electrode portion reaches the melting point (active temperature) of the flux first, the oxide film on the surface of the conductive particles that has preferentially moved onto the electrode is removed, and the solder in the conductive particles is the electrode. Can be wet and spread on the surface of the. As a result, the conductive particles can be efficiently aggregated on the electrode.

The flux is preferably a flux that releases cations by heating. The use of a flux that releases cations upon heating allows the conductive particles to be placed more efficiently on the electrodes.

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

From the viewpoint of more efficiently arranging the conductive particles on the electrode, more effectively enhancing the insulation reliability, and further effectively enhancing the conduction reliability, the above-mentioned flux is a compound with an acid compound. It is preferably a salt with a basic compound.

The acid compound is preferably an organic compound having a carboxyl group. Examples of the acid compound include malonic acid, succinic acid, glutaric acid, adipic acid, pimelli acid, suberic acid, azelaic acid, sebacic acid, citric acid, malic acid, and cyclic aliphatic carboxylic acid, which are aliphatic carboxylic acids. Examples thereof include cyclohexylcarboxylic acid, 1,4-cyclohexyldicarboxylic acid, aromatic carboxylic acids isophthalic acid, terephthalic acid, trimellitic acid, ethylenediamine tetraacetic acid and the like. From the viewpoint of more efficiently arranging the conductive particles on the electrode, more effectively enhancing the insulation reliability, and further effectively enhancing the conduction reliability, the acid compound is glutaric acid. , Cyclohexylcarboxylic acid, or adipic acid is preferred.

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

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

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

The conductive material preferably does not contain the filler or contains the filler in an amount of 5% by weight or less. When the thermosetting compound is used, the smaller the filler content, the easier it is for the solder particles to move onto the electrodes.

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

(Other ingredients)
The conductive material may be, for example, a filler, a bulking agent, a softener, a plasticizer, a thickener, a thixo agent, a leveling agent, a polymerization catalyst, a curing catalyst, a colorant, an antioxidant, a heat stabilizer, if necessary. , Light stabilizers, UV absorbers, lubricants, antistatic agents, flame retardants and the like.

(Connection structure and manufacturing method of connection structure)
The connection structure according to the present invention includes a first connection target member having a first electrode on the surface, a second connection target member having a second electrode on the surface, and the first connection target member. It includes a connecting portion that connects to the second connection target member. In the connection structure according to the present invention, the material of the connection portion is the above-mentioned conductive material. In the connection structure according to the present invention, the first electrode and the second electrode are electrically connected by the conductive particles. It is preferable that the first electrode and the second electrode are arranged in a line.

In a specific aspect, the method for manufacturing a connection structure according to the present invention is to use a line of the first electrode on the surface of a first connection target member having the first electrodes arranged in a line on the surface. Along with the above, a step of applying the above-mentioned conductive material in a line shape is provided. The method for manufacturing a connection structure according to the present invention is a second connection having a second electrode arranged in a line on the surface of the conductive material opposite to the first connection target member side. A step of arranging the target member so that the first electrode and the second electrode face each other is provided. In the method for manufacturing a connection structure according to the present invention, the conductive material is used to connect the first connection target member and the second connection target member by heating the conductive material. It is provided with a step of forming and electrically connecting the first electrode and the second electrode with the conductive particles.

In a specific aspect, the method for manufacturing a connection structure according to the present invention is to use a line of the first electrode on the surface of a first connection target member having the first electrodes arranged in a line on the surface. Along with the above, a coating step of applying a conductive material containing a thermosetting component and a thermosetting agent in a line shape is provided. The method for manufacturing a connection structure according to the present invention is a second connection having a second electrode arranged in a line on the surface of the conductive material opposite to the first connection target member side. The target member is provided with an arrangement step of arranging the target member so that the first electrode and the second electrode face each other. In the method for manufacturing a connection structure according to the present invention, the conductive material is used to connect the first connection target member and the second connection target member by heating the conductive material. It is provided with a connection step of forming and electrically connecting the first electrode and the second electrode with the conductive particles. In the method for manufacturing a connecting structure according to the present invention, the width of the conductive material at the start of heating of the conductive material in the connection step is set to Xa1, and the temperature of the conductive material reaches 100 ° C. after the heating of the conductive material is started. When the width of the conductive material at the time of reaching is Xa2, Xa2 is set to 1.25 times or less of Xa1. In other words, in the method for manufacturing a connection structure according to the present invention, the ratio of Xa2 to Xa1 is set to 1.25 or less. In the method for producing a connection structure according to the present invention, it is preferable to start heating from a temperature of 40 ° C. or lower.

Since the connection structure and the method for manufacturing the connection structure according to the present invention have the above-mentioned configuration, the conduction reliability between the electrodes in the vertical direction can be effectively improved, and the conduction between the adjacent line electrodes can be effectively improved. Insulation reliability can be effectively improved.

The present inventors have found that by adopting a specific connection structure manufacturing process, it is possible to maintain a line-like shape at the time of conductive connection, and it is possible to efficiently connect electrodes. In the present invention, even in the case of connection between line electrodes, it is possible to effectively enhance the conduction reliability between the electrodes in the vertical direction to be connected. Further, when there are a plurality of line electrodes adjacent to each other in the lateral direction, the insulation reliability between the adjacent line electrodes can be effectively improved.

In the present invention, in order to obtain the above-mentioned effects, it is greatly contributed to adopt the manufacturing process of a specific connection structure.

The ratio of Xa2 to Xa1 (Xa2 / Xa1) is 1.25 or less. The above ratio (Xa2 / Xa1) is preferably 1.20 or less, more preferably 1.10 or less. The lower limit of the above ratio (Xa2 / Xa1) is not particularly limited. The above ratio (Xa2 / Xa1) may be 1.01 or more. When the ratio (Xa2 / Xa1) is equal to or higher than the lower limit and lower than the upper limit, the conduction reliability between the electrodes in the vertical direction can be further effectively increased, and the insulation reliability between the adjacent line electrodes can be improved. It can be enhanced even more effectively.

The width of the conductive material at the start of heating of the conductive material in the connection step is Xa1. The length of the conductive material at the start of heating of the conductive material in the connection step is Ya1, and the thickness is Za1.

From the viewpoint of further effectively enhancing the conduction reliability between the electrodes in the vertical direction and further effectively enhancing the insulation reliability between the adjacent line electrodes, the width Xa1 is preferably 150 μm or more. It is preferably 200 μm or more, preferably 300 μm or less, and more preferably 275 μm or less.

From the viewpoint of further effectively enhancing the conduction reliability between the electrodes in the vertical direction and further effectively enhancing the insulation reliability between the adjacent line electrodes, the length Ya1 is preferably 1000 μm or more. It is more preferably 1500 μm or more, preferably 4000 μm or less, and more preferably 3000 μm or less.

From the viewpoint of further effectively enhancing the conduction reliability between the electrodes in the vertical direction and further effectively enhancing the insulation reliability between the adjacent line electrodes, the thickness Za1 is preferably 100 μm or more. It is more preferably 125 μm or more, preferably 300 μm or less, and more preferably 275 μm or less.

In the method for manufacturing a connection structure according to the present invention, the conductive material may be applied so as to have a width of 250 ± 20 μm, a length of 2200 ± 20 μm, and a thickness of 150 ± 30 μm, and may have a width of 250 ± 20 μm and a length of 2200. It may be applied in a size different from ± 20 μm and a thickness of 150 ± 30 μm.

In the method for manufacturing a connection structure according to the present invention, the conductive material may be heated and pressurized under the pressure condition of 60 Pa and the condition of heating from 40 ° C. to 170 ° C. at a heating rate of 1.08 ° C./sec. In the method for manufacturing a connection structure according to the present invention, the conductive material is heated and pressurized under conditions other than the pressure condition of 60 Pa and the condition of heating from 40 ° C. to 170 ° C. at a heating rate of 1.08 ° C./sec. May be good.

Further, in order to efficiently arrange the conductive particles on the electrodes and to considerably reduce the amount of the conductive particles arranged in the region where the electrodes are not formed, the conductive material is not a conductive film but a conductive film. It is preferable to use a conductive paste.

The thickness of the solder portion between the electrodes is preferably 10 μm or more, more preferably 20 μm or more, preferably 100 μm or less, and more preferably 80 μm or less. The solder wet area on the surface of the electrode (the area in contact with the solder in the exposed area of the electrode) is preferably 50% or more, more preferably 70% or more, and preferably 100% or less.

In the method for manufacturing a connection structure according to the present invention, no pressurization is performed in the step of arranging the second connection target member and the step of forming the connection portion, and the conductive material is connected to the second connection. It is preferable that the weight of the target member is added. In the method for manufacturing a connection structure according to the present invention, in the step of arranging the second connection target member and the step of forming the connection portion, the conductive material is subjected to the force of the weight of the second connection target member. It is preferable that no pressurizing pressure exceeding the above is applied. In these cases, the uniformity of the amount of conductive particles can be further enhanced among the plurality of electrodes. Furthermore, the thickness of the solder portion between the electrodes can be increased more effectively, a large number of conductive particles can easily gather between the electrodes, and the plurality of conductive particles can be more efficiently collected on the electrodes (lines). Can be arranged as a target. Further, it is difficult for some of the plurality of conductive particles to be arranged in the region (space) where the electrode is not formed, and the amount of the conductive particles arranged in the region where the electrode is not formed can be further reduced. can. Therefore, the continuity reliability between the electrodes can be further improved. Moreover, it is possible to further prevent electrical connection between the line electrodes adjacent to each other in the lateral direction which should not be connected, and it is possible to further improve the insulation reliability.

Further, if a conductive paste is used instead of the conductive film, it becomes easy to adjust the thickness of the connecting portion and the solder portion depending on the amount of the conductive paste applied. On the other hand, in the case of the conductive film, in order to change or adjust the thickness of the connecting portion, it is necessary to prepare a conductive film having a different thickness or a conductive film having a predetermined thickness. There is. Further, in the conductive film, the melt viscosity of the conductive film cannot be sufficiently lowered as compared with the conductive paste, and the aggregation of the conductive particles tends to be hindered easily.

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

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

The connection structure 1 shown in FIG. 1 is a connection connecting the first connection target member 2, the second connection target member 3, the first connection target member 2, and the second connection target member 3. A unit 4 is provided. The connecting portion 4 is formed of the above-mentioned conductive material. In this embodiment, the conductive material contains a thermosetting component and conductive particles. In this embodiment, solder particles are used as the conductive particles. In this embodiment, a conductive paste is used as the conductive material.

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

The first connection target member 2 has a plurality of first electrodes 2a on the surface (upper surface). The plurality of first electrodes 2a are arranged in a line. In FIG. 1, a plurality of first electrodes 2a are arranged side by side in the left-right direction. The line-shaped first electrode 2a (line electrode) is an aggregate of a plurality of first electrodes 2a. The second connection target member 3 has a plurality of second electrodes 3a on the surface (lower surface). The plurality of second electrodes 3a are arranged in a line. In FIG. 1, the plurality of second electrodes 3a are arranged side by side in the left-right direction. The line-shaped second electrode 3a (line electrode) is an aggregate of a plurality of second electrodes 3a.

The first electrode 2a and the second electrode 3a are electrically connected by the solder portion 4A. Therefore, the first connection target member 2 and the second connection target member 3 are electrically connected by the solder portion 4A. In the connecting portion 4, the solder particles do not exist in the region (cured product portion 4B portion) different from the solder portion 4A gathered between the first electrode 2a and the second electrode 3a. In the region different from the solder portion 4A (cured product portion 4B portion), there are no solder particles separated from the solder portion 4A. If the amount is small, the solder particles may be present in a region (cured product portion 4B portion) different from the solder portion 4A gathered between the first electrode 2a and the second electrode 3a.

As shown in FIG. 1, in the connection structure 1, a plurality of solder particles are gathered between the first electrode 2a and the second electrode 3a, and after the plurality of solder particles are melted, the melt of the solder particles is formed. The surface of the electrode is wet and spread, and then solidified to form the solder portion 4A. Therefore, the connection area between the solder portion 4A and the first electrode 2a and the solder portion 4A and the second electrode 3a becomes large. That is, by using the solder particles, the solder portion 4A, the first electrode 2a, and the solder portion are compared with the case where the conductive particles whose conductive outer surface is a metal such as nickel, gold, or copper are used. The contact area between the 4A and the second electrode 3a becomes large. This also increases the continuity reliability and connection reliability of the connection structure 1. When the conductive material contains a flux, the flux is generally gradually deactivated by heating.

In the connection structure 1 shown in FIG. 1, all of the solder portions 4A are located in facing regions between the first and second electrodes 2a and 3a. In the connection structure 1X of the modified example shown in FIG. 3, only the connection portion 4X is different from the connection structure 1 shown in FIG. The connection portion 4X has a solder portion 4XA and a cured product portion 4XB. Like the connection structure 1X, most of the solder portions 4XA are located in the facing regions of the first and second electrodes 2a and 3a, and a part of the solder portions 4XA is the first and second electrodes. The electrodes 2a and 3a may protrude laterally from the facing regions. The solder portion 4XA protruding laterally from the facing regions of the first and second electrodes 2a and 3a is a part of the solder portion 4XA and is not a solder particle separated from the solder portion 4XA. In this embodiment, the amount of solder particles separated from the solder portion can be reduced, but the solder particles separated from the solder portion may be present in the cured product portion.

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

In the connection structures 1, 1X, when the portions facing each other of the first electrode 2a and the second electrode 3a are seen in the stacking direction of the first electrode 2a, the connection portions 4, 4X, and the second electrode 3a. It is preferable that the solder portions 4A and 4XA in the connecting portions 4 and 4X are arranged in 50% or more of the area of 100% of the portions facing each other of the first electrode 2a and the second electrode 3a. .. When the solder portions 4A and 4XA in the connection portions 4 and 4X satisfy the above-mentioned preferable embodiments, the continuity reliability can be further improved.

When the portions facing each other of the first electrode and the second electrode are seen in the stacking direction of the first electrode, the connection portion, and the second electrode, the first electrode and the second electrode are seen. It is preferable that the solder portion in the connection portion is arranged in 50% or more of the area of 100% of the portions facing the electrodes of 2. When the portions facing each other of the first electrode and the second electrode are seen in the stacking direction of the first electrode, the connection portion, and the second electrode, the first electrode and the second electrode are seen. It is more preferable that the solder portion in the connection portion is arranged in 60% or more of the area of 100% of the portions facing the electrodes of 2. When the portions facing each other of the first electrode and the second electrode are seen in the stacking direction of the first electrode, the connection portion, and the second electrode, the first electrode and the second electrode are seen. It is more preferable that the solder portion in the connection portion is arranged in 70% or more of the area of 100% of the portions facing the electrodes of 2. When the portions facing each other of the first electrode and the second electrode are seen in the stacking direction of the first electrode, the connection portion, and the second electrode, the first electrode and the second electrode are seen. It is particularly preferable that the solder portion in the connection portion is arranged in 80% or more of the area of 100% of the portions facing the electrodes of 2. When the portions facing each other of the first electrode and the second electrode are seen in the stacking direction of the first electrode, the connection portion, and the second electrode, the first electrode and the second electrode are seen. It is most preferable that the solder portion in the connection portion is arranged in 90% or more of the area of 100% of the portions facing the electrodes of 2. When the solder portion in the connection portion satisfies the above-mentioned preferable embodiment, the continuity reliability can be further improved.

When the portion where the first electrode and the second electrode face each other is seen in a direction orthogonal to the stacking direction of the first electrode, the connection portion, and the second electrode, the first electrode is used. It is preferable that 60% or more of the solder portion in the connection portion is arranged at the portion where the electrode and the second electrode face each other. When the portion where the first electrode and the second electrode face each other is seen in a direction orthogonal to the stacking direction of the first electrode, the connection portion, and the second electrode, the first electrode is used. It is more preferable that 70% or more of the solder portion in the connection portion is arranged at the portion where the electrode and the second electrode face each other. When the portion where the first electrode and the second electrode face each other is seen in a direction orthogonal to the stacking direction of the first electrode, the connection portion, and the second electrode, the first electrode is used. It is more preferable that 90% or more of the solder portion in the connection portion is arranged at the portion where the electrode and the second electrode face each other. When the portion where the first electrode and the second electrode face each other is seen in a direction orthogonal to the stacking direction of the first electrode, the connection portion, and the second electrode, the first electrode is used. It is particularly preferable that 95% or more of the solder portion in the connection portion is arranged at the portion where the electrode and the second electrode face each other. When the portion where the first electrode and the second electrode face each other is seen in a direction orthogonal to the stacking direction of the first electrode, the connection portion, and the second electrode, the first electrode is used. It is most preferable that 99% or more of the solder portion in the connection portion is arranged at the portion where the electrode and the second electrode face each other. When the solder portion in the connection portion satisfies the above-mentioned preferable embodiment, the continuity reliability can be further improved.

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

First, a first connection target member 2 having a first electrode 2a arranged in a line on the surface (upper surface) is prepared. Next, as shown in FIG. 2A, the conductive material 11 containing the thermosetting component 11B and the plurality of solder particles 11A is applied in a line on the surface of the first connection target member 2 (). First step, coating step). The conductive material 11 used contains a thermosetting compound and a thermosetting agent as the thermosetting component 11B.

The conductive material 11 is applied in a line shape along the line of the first electrode 2a on the surface provided with the first electrode 2a arranged in a line shape of the first connection target member 2. After the arrangement of the conductive material 11, the solder particles 11A are arranged both on the first electrode 2a (line electrode) and on the region (space) where the first electrode 2a is not formed.

The method of arranging the conductive material 11 is not particularly limited, and examples thereof include coating with a dispenser, screen printing, and ejection with an inkjet device.

Further, a second connection target member 3 having a second electrode 3a arranged in a line on the surface (lower surface) is prepared. Next, as shown in FIG. 2B, in the conductive material 11 on the surface of the first connection target member 2, on the surface of the conductive material 11 opposite to the first connection target member 2 side. The second connection target member 3 is arranged (second step, arrangement step). The second connection target member 3 is arranged on the surface of the conductive material 11 from the second electrode 3a side. At this time, the first electrode 2a and the second electrode 3a are opposed to each other.

Next, the conductive material 11 is heated above the melting point of the solder particles 11A (third step, connection step). Preferably, the conductive material 11 is heated above the curing temperature of the thermosetting component 11B (thermosetting compound). At the time of this heating, the solder particles 11A existing in the region where the electrodes are not formed gather between the first electrode 2a and the second electrode 3a (self-aggregation effect). When a conductive paste is used instead of the conductive film, the solder particles 11A are more effectively collected between the first electrode 2a and the second electrode 3a. Further, the solder particles 11A are melted and joined to each other. Further, the thermosetting component 11B is thermoset. 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 of the conductive material 11. The connecting portion 4 is formed by the conductive material 11, the solder portion 4A is formed by joining the plurality of solder particles 11A, and the cured product portion 4B is formed by thermosetting the thermosetting component 11B. If the solder particles 11A move sufficiently, the solder particles 11A that are not located between the first electrode 2a and the second electrode 3a start to move, and then the first electrode 2a and the second electrode 2a and the second electrode It is not necessary to keep the temperature constant until the movement of the solder particles 11A to and from 3a is completed.

In the present embodiment, it is preferable not to pressurize in the second step and the third step. In this case, the weight of the second connection target member 3 is added to the conductive material 11. Therefore, when the connecting portion 4 is formed, the solder particles 11A gather more effectively between the first electrode 2a and the second electrode 3a. When pressure is applied in at least one of the second step and the third step, the solder particles 11A tend to gather between the first electrode 2a and the second electrode 3a. Is more likely to be inhibited.

Further, in the present embodiment, since the pressurization is not performed, the first connection target member 2 and the second connection target member 3 are in a state where the first electrode 2a and the second electrode 3a are out of alignment. Even when and are overlapped with each other, the deviation can be corrected and the first electrode 2a and the second electrode 3a can be connected (self-alignment effect). This is because the molten solder that is self-aggregated between the first electrode 2a and the second electrode 3a is the solder between the first electrode 2a and the second electrode 3a and other conductive materials. This is because the one where the area in contact with the component is the minimum is energetically stable, and the force for making the connected structure with alignment, which is the connection structure with the minimum area, works. At this time, it is desirable that the conductive material is not cured and that the viscosity of the components other than the solder particles of the conductive material is sufficiently low at the temperature and time.

The viscosity of the conductive material at the melting point of the solder particles is preferably 50 Pa · s or less, more preferably 10 Pa · s or less, still more preferably 1 Pa · s or less, preferably 0.1 Pa · s or more, and more preferably 0. .2 Pa · s or more. When the viscosity is not more than the upper limit, the solder particles can be efficiently aggregated. When the viscosity is at least the above lower limit, voids at the connecting portion can be suppressed, and the protrusion of the conductive material to other than the connecting portion can be suppressed.

For the viscosity of the conductive material at the melting point of the solder particles, strain control 1 rad, frequency 1 Hz, temperature rise rate 20 ° C./min, measurement temperature range 25 to 200 ° C. (however, solder) using STRESSTECH (manufactured by REOLOGICA) or the like. When the melting point of the particles exceeds 200 ° C., the upper limit of the temperature is taken as the melting point of the solder particles). From the measurement results, the viscosity of the solder particles at the melting point (° C) is evaluated.

In this way, the connection structure 1 shown in FIG. 1 is obtained. The second step and the third step may be continuously performed. Further, after performing the second step, the obtained laminate of the first connection target member 2, the conductive material 11 and the second connection target member 3 is moved to the heating unit, and the third The process may be performed. In order to perform the heating, the laminate may be arranged on the heating member, or the laminate may be arranged in the heated space.

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

As a heating method in the third step, a method of heating the entire connection structure using a reflow furnace or an oven or a connection structure above the melting point of the solder particles and above the curing temperature of the thermosetting component. A method of locally heating only the connection part of the body can be mentioned.

Examples of the appliance used for the method of locally heating include a hot plate, a heat gun for applying hot air, a soldering iron, an infrared heater, and the like.

When locally heating on a hot plate, use a metal with high thermal conductivity directly under the connection, and use a material with low thermal conductivity such as fluororesin in other areas where heating is not preferable. , It is preferable to form the upper surface of the hot plate.

The first and second connection target members are not particularly limited. Specific examples of the first and second connection target members include electronic components such as semiconductor chips, semiconductor packages, LED chips, LED packages, capacitors and diodes, resin films, printed circuit boards, flexible printed circuit boards, and flexible devices. Examples thereof include electronic components such as flat cables, rigid flexible boards, glass epoxy boards, circuit boards such as glass boards, and the like. The first and second connection target members are preferably electronic components.

It is preferable that at least one of the first connection target member and the second connection target member is a resin film, a flexible printed substrate, 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 substrate, a flexible flat cable, or a rigid flexible substrate. Resin films, flexible printed substrates, flexible flat cables and rigid flexible substrates have the properties of high flexibility and relatively light weight. When a conductive film is used for connecting such a member to be connected, solder particles tend to be difficult to collect on the electrodes. On the other hand, by using the conductive paste, even if a resin film, a flexible printed substrate, a flexible flat cable or a rigid flexible substrate is used, the solder particles are efficiently collected on the electrodes, so that the conduction between the electrodes is reliable. The sex can be sufficiently enhanced. When a resin film, flexible printed substrate, flexible flat cable, or rigid flexible substrate is used, the conduction reliability between the electrodes due to no pressurization is higher than when other connected members such as semiconductor chips are used. The improvement effect can be obtained even more effectively.

Examples of the electrodes provided on the connection target member include metal electrodes such as gold electrodes, nickel electrodes, tin electrodes, aluminum electrodes, copper electrodes, molybdenum electrodes, silver electrodes, SUS electrodes, and tungsten electrodes. When the connection target member is a flexible printed substrate, the electrode is preferably a gold electrode, a nickel electrode, a tin electrode, a silver electrode, or a copper electrode. When the connection target member is a glass substrate, the electrode is preferably an aluminum electrode, a copper electrode, a molybdenum electrode, a silver electrode, or a tungsten electrode. 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 a 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.

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

Hereinafter, the present invention will be specifically described with reference to Examples and Comparative Examples. The present invention is not limited to the following examples.

Thermosetting component (thermosetting compound):
Thermosetting compound 1: Novolac type epoxy compound, "DEN431" manufactured by The Dow Chemical Company, Inc.
Thermosetting compound 2: Dicyclopentadiene type epoxy compound, "HP7200HH" manufactured by DIC Corporation

Thermosetting component (thermosetting agent):
Thermosetting agent 1: "Ricashid TH" manufactured by Shin Nihon Rika Co., Ltd.
Thermosetting agent 2: "Ricacid MH700" manufactured by Shin Nihon Rika Co., Ltd.

Thermosetting component (curing accelerator):
Curing accelerator 1: "PX-4MP" manufactured by Nippon Chemical Industrial Co., Ltd.

flux:
Flux 1: "Glutaric acid benzylamine salt", melting point 108 ° C

Method for producing flux 1:
In a glass bottle, 24 g of water as a reaction solvent and 13.212 g of glutaric acid (manufactured by Wako Pure Chemical Industries, Ltd.) were put and dissolved at room temperature until uniform. Then, 10.715 g of benzylamine (manufactured by Wako Pure Chemical Industries, Ltd.) was added and stirred for about 5 minutes to obtain a mixed solution. The obtained mixed solution was placed in a refrigerator at 5 to 10 ° C. and left overnight. The precipitated crystals were separated by filtration, washed with water and vacuum dried to obtain flux 1.

Conductive particles:
Conductive particles 1: SnBi solder particles, melting point 138 ° C, solder particles selected from "Sn42Bi58" manufactured by Mitsui Kinzoku Co., Ltd., particle size: 12 μm

Filler: Filler:
Filler 1: "AEROSIL R7200" manufactured by Aerosil Japan
Filler 2: "Micropearl SP-275" manufactured by Sekisui Chemical Co., Ltd.

(Examples 1 to 3 and Comparative Examples 1 to 4)
(1) Preparation of Conductive Material (Anisotropic Conductive Paste) A conductive material (anisotropic conductive paste) was obtained by blending the components shown in Table 1 below in the blending amounts shown in Table 1 below.

(2) Preparation of connection structure As the first connection target member, glass having a line electrode (material: copper) having a width of 250 μm, a length of 2200 μm, and a thickness of 150 μm on the surface of a glass epoxy substrate main body (material FR-4). An epoxy board was prepared. One line electrode is an aggregate of electrodes in which a plurality of electrodes having an electrode length of 300 μm are arranged in the length direction of the line electrode with a length between electrodes of 200 μm. The glass epoxy substrate has a plurality of line electrodes.

As a second connection target member, a semiconductor chip having a line electrode (material: copper) having a width of 250 μm, a length of 2200 μm, and a thickness of 150 μm was prepared on the surface of the semiconductor chip main body. One line electrode is an aggregate of electrodes in which a plurality of electrodes having an electrode length of 300 μm are arranged in the length direction of the line electrode with a length between electrodes of 200 μm. The semiconductor chip has a plurality of line electrodes.

On the upper surface of the line electrode of the glass epoxy substrate, the conductive material (anisotropic conductive paste) immediately after production is spread along the line electrode so as to have a width of 250 ± 20 μm, a length of 2200 ± 20 μm, and a thickness of 150 ± 30 μm. It was applied to form a conductive material (anisotropic conductive paste) layer. Next, semiconductor chips were laminated on the upper surface of the conductive material (anisotropic conductive paste) layer so that the electrodes face each other. The weight of the semiconductor chip is added to the conductive material (anisotropic conductive paste) layer. From that state, the temperature of the conductive material (anisotropic conductive paste) layer was heated to reach the melting point of the solder 90 seconds after the start of temperature rise. Further, 120 seconds after the start of temperature rise, the conductive material (anisotropic conductive paste) layer is heated to 170 ° C. to cure the conductive material (anisotropic conductive paste) layer, and the connection structure is formed. Obtained. No pressurization was performed during heating.

(evaluation)
(1) Shape maintenance characteristics of conductive material A glass epoxy substrate and a semiconductor chip used for manufacturing a connection structure were prepared. The obtained conductive material was applied to the upper surface of the line electrode of the glass epoxy substrate along the line of the line electrode so as to have a width of 250 ± 20 μm, a length of 2200 ± 20 μm, and a thickness of 150 ± 30 μm. A cover glass having a short side of 1500 μm, a long side of 2400 μm, and a thickness of 150 μm is placed on the conductive material with a tweezers or a mounter so that the long side portion coincides with the length direction of the conductive material, and 60 Pa is placed on the conductive material. It was allowed to stand under the condition of applying pressure. The width X1 of the conductive material when allowed to stand was measured. After standing, the conductive material was pressurized and heated under the pressure condition of 60 Pa and the condition of heating from 40 ° C. to 170 ° C. at a heating rate of 1.08 ° C./sec. The width X2 of the conductive material was measured when the conductive material reached 100 ° C. From the obtained measurement results, the ratio of X2 to X1 (X2 / X1) was calculated. The shape maintenance characteristics of the conductive material were judged according to the following criteria.

[Criteria for determining the shape maintenance characteristics of conductive materials]
◯: X2 / X1 is 1.18 or less Δ: X2 / X1 exceeds 1.18 and 1.25 or less ×: X2 / X1 exceeds 1.25

(2) Insulation between adjacent line electrodes By observing between the line electrodes with an optical electron microscope in the obtained connection structure, it was confirmed whether or not there was a spread of the conductive material between the line electrodes. .. The insulation between adjacent line electrodes was determined according to the following criteria.

[Criteria for determining insulation between adjacent line electrodes]
◯: There is no spread of the conductive material between the adjacent line electrodes, and the insulation between the adjacent line electrodes is good. ×: There is a spread of the conductive material between the adjacent line electrodes, and the adjacent lines Poor insulation between electrodes

(3) Precision of solder placement on the electrode In the obtained connection structure, the portion where the first electrode and the second electrode face each other in the stacking direction of the first electrode, the connection portion, and the second electrode. The ratio Y of the area where the solder portion in the connecting portion is arranged in the area of 100% of the portions facing each other of the first electrode and the second electrode was evaluated. The accuracy of solder placement on the electrodes was judged according to the following criteria. The ratio Y can be measured by using image analysis software "ImageJ" or the like in observation with an optical microscope.

[Criteria for determining the accuracy of solder placement on electrodes]
XX: Ratio Y is 70% or more ○: Ratio Y is 60% or more and less than 70% Δ: Ratio Y is 50% or more and less than 60% ×: Ratio Y is less than 50% The results are shown in Table 1 below.

The same tendency can be seen when a flexible printed substrate, a resin film, a flexible flat cable and a rigid flexible substrate are used.

1,1X ... Connection structure 2 ... First connection target member 2a ... First electrode 3 ... Second connection target member 3a ... Second electrode 4,4X ... Connection part 4A, 4XA ... Solder part 4B, 4XB … Cured material part 11… Conductive material 11A… Solder particles 11B… Thermocurable component 21… Conductive particles (solder particles)
31 ... Conductive particles 32 ... Base particles 33 ... Conductive parts (conductive parts with solder)
33A ... Second conductive part 33B ... Solder part 41 ... Conductive particles 42 ... Solder part 51 ... Member 51A ... Electrode aggregate 51a ... Electrode

Claims (9)

A conductive material containing a thermosetting component and conductive particles.
The conductive material is applied in a line on the first member so as to have a width of 250 ± 20 μm, a length of 2200 ± 20 μm, and a thickness of 150 ± 30 μm, and the second member is placed on the conductive material. , The width of the conductive material when allowed to stand under a pressure condition of 60 Pa is X1, and after standing, a pressure condition of 60 Pa and a condition of heating from 40 ° C. to 170 ° C. at a heating rate of 1.08 ° C./sec. A conductive material in which X2 is 1.25 times or less of X1 when the width of the conductive material is X2 when the conductive material reaches 100 ° C. by pressurizing and heating the conductive material. The conductive material according to claim 1, wherein the conductive particles are solder particles. The conductive material according to claim 1 or 2, wherein the minimum value of the melt viscosity of the conductive material in a temperature region of 140 ° C. or lower is 50 Pa · s or more. The conductive material according to any one of claims 1 to 3, wherein the thermosetting component contains a thermosetting compound and a thermosetting agent. The conductive material according to any one of claims 1 to 4, which comprises a flux. The conductive material according to any one of claims 1 to 5, which is a conductive paste. The conductive material according to any one of claims 1 to 6, which is applied and used in a line shape. A first connection target member having a first electrode on its surface,
A second connection target member having a second electrode on the surface,
The first connection target member and the connection portion connecting the second connection target member are provided.
The material of the connection portion is the conductive material according to any one of claims 1 to 7.
A connection structure in which the first electrode and the second electrode are electrically connected by the conductive particles. The conductivity according to any one of claims 1 to 7, along the line of the first electrode, on the surface of the first connection target member having the first electrode arranged in a line on the surface. The process of applying the material in a line and
A second connection target member having a second electrode arranged in a line on the surface of the conductive material opposite to the first connection target member side is provided with the first electrode and the first electrode. The process of arranging the electrodes of 2 so as to face each other,
By heating the conductive material, a connecting portion connecting the first connection target member and the second connection target member is formed by the conductive material, and the first electrode and the said. A method for manufacturing a connection structure, comprising a step of electrically connecting a second electrode with the conductive particles.

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