JP2019096549A - Conductive material, connection structure and production method of connection structure - Google Patents

Abstract

To provide a conductive material capable of effectively enhancing communication reliability between electrodes in a vertical direction.SOLUTION: A conductive material according to the present invention is a conductive material containing a thermosetting component and conductive particles and obtained by coating in line the conductive material on the first member such that a width is 250±20 μm, a length is 2200±20 μm, and a thickness is 150±30 μm, followed by placing the second member on the conductive material. When a width of the conductive material when left under pressure condition of 60 Pa is set to X1, and a width of the conductive material at the time point when the conductive material reaches 100°C by pressurizing and heating the conductive material under pressure condition of 60 Pa after leaving still, and a condition of heating at a temperature increase rate of 1.08°C/second from 40°C to 170°C is set to X2, X2 is 1.25 times or smaller the X1.SELECTED DRAWING: Figure 1

Description

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

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

  The anisotropic conductive material is used to obtain various connection structures. As the connection by the anisotropic conductive material, for example, connection of a flexible printed substrate and a glass substrate (FOG (Film on Glass)), connection of a semiconductor chip and a flexible printed substrate (COF (Chip on Film)), semiconductor The connection between a chip and a glass substrate (COG (Chip on Glass)), the connection between a flexible printed substrate and a glass epoxy substrate (FOB (Film on Board)), and the like can be mentioned.

  For example, when electrically connecting an electrode of a flexible printed board and an electrode of a glass epoxy board with the above-mentioned anisotropic conductive material, an anisotropic conductive material containing conductive particles is arranged on the glass epoxy board Do. Next, the flexible printed circuit is laminated, and heated and pressurized. Thus, the anisotropic conductive material is cured to electrically connect the electrodes 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 of the surface of the solder particle 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 lower by 10 ° C. or more than the melting point of the solder powder. The content of the first epoxy resin is 10 parts by weight to 75 parts by weight with respect to 100 parts by weight of the entire composite epoxy resin.

JP, 2016-076494, A Unexamined-Japanese-Patent No. 2017-080797

  In recent years, mounting has been performed on small electrodes having narrow electrode widths and inter-electrode widths. In such an implementation, a line electrode in which a plurality of electrodes are arranged in a line may be used.

  A conductive material may be used to connect electronic components such as semiconductor devices having line electrodes. In the connection of the line electrodes, a conductive material may be applied in a line on the line electrodes in order to efficiently perform the connection between the electrodes. The conductive material applied in a line is required to electrically connect between 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 apply the conductive material accurately in a line shape on the line electrode. In addition, when a conventional conductive material having a low melt viscosity is applied onto the 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-like shape can not 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 disposed in the area where the line electrode is not formed, and the solder particles or the conductive between the vertical electrodes to be connected It becomes difficult to arrange the sexing particles efficiently. As a result, in the conventional conductive material, the conduction reliability between the electrodes may be low.

  Also, in the case where there are a plurality of line electrodes adjacent in the lateral direction, in the conventional conductive material, the solder particles or the conductive particles should not be connected by being disposed in the region where the line electrode is not formed. Adjacent line electrodes may be electrically connected. As a result, in the conventional conductive material, the insulation reliability between adjacent line electrodes may be low.

  An object of the present invention is to provide a conductive material capable of effectively enhancing the conduction reliability between electrodes in the vertical direction. Moreover, the objective of this invention is providing the manufacturing method of the connection structure which used the said electrically-conductive material, and a connection structure.

  According to a broad aspect of the present invention, it is a conductive material comprising a thermosetting component and conductive particles, and on the first member, the conductive material has a width of 250 ± 20 μm, a length of 2200 ± 20 μm, a thickness The conductive material is applied in a line shape to have a thickness of 150 ± 30 μm, the second member is placed on the conductive material, and the width of the conductive material when left to stand under a pressure condition of 60 Pa is X1. Under pressure and heating conditions from 40 ° C. to 170 ° C. at a heating rate of 1.08 ° C./s, the conductive material is pressurized and heated, and the conductive material reaches 100 ° C. Provided that the width of the conductive material is X2, a conductive material is provided in which X2 is 1.25 times or less of X1.

  In a specific aspect 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 a temperature range of 140 ° C. or less is 50 Pa · s or more.

  In a specific aspect of the conductive material according to the present invention, the thermosetting component contains a thermosetting compound and a thermosetting agent.

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

  In a specific aspect 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 in a line form.

  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 And a connecting portion connecting the second connection target member, the material of the connecting portion is the above-described conductive material, and the first electrode and the second electrode are the conductive. A connection structure is provided, which is electrically connected by particles.

  According to a broad aspect of the present invention, on the surface of a first connection target member having a first electrode arranged in a line on the surface, the above-mentioned conductive material is provided along the line of the first electrode. A step of applying in a line shape, and a second connection target member having on the surface a second electrode arranged in a line shape on the surface of the conductive material opposite to the first connection target member side, A step of arranging the first electrode and the second electrode to face each other, and heating the conductive material to connect the first connection target member and the second connection target member. Forming a connecting portion made of 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 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. Applying a conductive material including conductive particles in a line, and a second electrode disposed in a line on the surface of the conductive material opposite to the first connection target member. Disposing the second connection target member on the surface such that the first electrode and the second electrode face each other, and heating the conductive material to form the first connection target member And a connection portion connecting the second connection target member and the second connection target member are formed of the conductive material, and the first electrode and the second electrode are electrically connected by the conductive particles. And the start of heating of the conductive material in the connecting step. Assuming that the width of the conductive material is Xa1, and the width of the conductive material is Xa2 when the conductive material reaches 100 ° C. after heating of the conductive material is started, Xa2 is 1.25 of Xa1. Provided is a method of manufacturing a connection structure that is less than doubled.

  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 shape 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, the second member is placed on the conductive material, and the width of the conductive material when left to stand under a pressure condition of 60 Pa is X1, and after standing, the pressure condition of 60 Pa and the temperature rising rate of 1.08. The conductive material is pressurized and heated under the conditions of heating from 40 ° C. to 170 ° C./° C./sec, and the width of the conductive material when the conductive material reaches 100 ° C. is X2. In the conductive material according to the present invention, the width X2 is not more than 1.25 times the width X1. In the conductive material according to the present invention, since the above configuration is provided, the conduction reliability between the electrodes in the vertical direction can be effectively improved. Furthermore, in the case where there are a plurality of line electrodes, in the conductive material according to the present invention, insulation reliability between adjacent line electrodes can be effectively enhanced.

  In the method of manufacturing a connection structure according to the present invention, heat curing is performed 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. And a coating step of applying a conductive material including the sex component and the conductive particles in a line. In the method of manufacturing a connection structure according to the present invention, a second connection having on the surface a second electrode arranged in a line on the surface of the conductive material opposite to the first connection target member side is provided. And an arranging step of arranging the target member such that the first electrode and the second electrode face each other. In the method of manufacturing a connection structure according to the present invention, the connection portion connecting the first connection target member and the second connection target member by heating the conductive material is made of the conductive material. And a connecting step of electrically connecting the first electrode and the second electrode with the conductive particles. In the method for manufacturing a connection 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 Xa1, and the heating of the conductive material is started to 100 ° C. When the width of the conductive material at the time of reaching is Xa2, Xa2 is made 1.25 times or less of Xa1. In the method for manufacturing a connection structure according to the present invention, since the above-described configuration is provided, the conduction reliability between the electrodes in the vertical direction can be effectively enhanced. Furthermore, when there are a plurality of line electrodes, in the method of manufacturing a connection structure according to the present invention, insulation reliability between adjacent line electrodes can be effectively enhanced.

FIG. 1 is a cross-sectional view schematically showing a connection structure obtained by using a conductive material according to an embodiment of the present invention. FIGS. 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 a conductive material according to an 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 for the conductive material. FIG. 5 is a cross-sectional view showing a second example of conductive particles usable for the conductive material. FIG. 6 is a cross-sectional view showing a third example of conductive particles usable for the conductive material. FIG. 7 is a diagram for explaining electrodes arranged in a line.

  Hereinafter, the present invention will be described in detail.

(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 shape 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, the second member is placed on the conductive material, and the width of the conductive material when left to stand under a pressure condition of 60 Pa is X1, and after standing, the pressure condition of 60 Pa and the temperature rising rate of 1.08. The conductive material is pressurized and heated under the conditions of heating from 40 ° C. to 170 ° C./° C./sec, and the width of the conductive material when the conductive material reaches 100 ° C. is X2. In the conductive material according to the present invention, the width X2 is not more than 1.25 times 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.

  In the conductive material according to the present invention, since the above configuration is provided, the conduction reliability between the electrodes in the vertical direction can be effectively improved. Furthermore, when there are a plurality of line electrodes adjacent in the lateral direction, the conductive material according to the present invention can effectively enhance the conduction reliability and effectively achieve the insulation reliability between the adjacent line electrodes. Can be raised.

  In the conventional conductive material, the viscosity of the conductive material is low, and it may be difficult to apply the conductive material accurately in a line shape on the line electrode. Moreover, when the conventional conductive material with low melt viscosity is apply | coated on a line electrode, a conductive material may flow excessively by heating by reflow etc. When the viscosity of the conductive material is low or the conductive material flows excessively, the line-like shape can not be maintained, and the conductive material spreads out of the line electrode. For this reason, the conductive particles are disposed in the region where the line electrodes are not formed, and the conductive particles can not be efficiently disposed between the vertical electrodes to be connected. In some cases, the reliability can not be improved sufficiently. In addition, the conductive particles are disposed in the area where the line electrodes are not formed, so that the adjacent line electrodes in the lateral direction that should not be connected are electrically connected, and the insulation reliability between the adjacent line electrodes is established. In some cases, it is not possible to improve sexuality.

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

  In the present invention, the use of a specific conductive material greatly contributes to obtaining the above-mentioned effects. The following method is mentioned as a method of obtaining a specific electrically-conductive material. A method of adjusting physical properties such as viscosity or thixotropy by adjusting the type or molecular weight of a thermosetting component. A method of adjusting physical properties such as viscosity or thixotropy by adjusting the type, surface treatment method, size, and blending amount of conductive particles. A method of adjusting physical properties such as viscosity or thixotropy by adjusting the type, size, and blending amount of a filler. A method of adjusting physical properties such as viscosity or thixotropy by adding a thickener, a thixo agent and the like to a conductive material.

  Furthermore, in the present invention, positional deviation between the electrodes can be prevented. In the present invention, when the second connection target member is superimposed on the first connection target member on the upper surface of which the conductive material is disposed, the electrode of the first connection target member and the electrode of the second connection target member Even in the state where the alignment is deviated, it is possible to correct the deviation and connect the electrodes (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 ratio (X2 / X1) is preferably 1.20 or less, more preferably 1.10 or less. The lower limit of the ratio (X2 / X1) is not particularly limited. The 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 more effectively enhanced, and the insulation reliability between adjacent line electrodes can be increased. It can be enhanced more effectively.

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

  The width of the conductive material, the width X1 and the width X2 can be obtained by averaging the entire width. The length of the conductive material can be obtained by averaging the entire length. The thickness of the conductive material can be obtained by averaging the overall 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 of 250 μm in width, 2200 μm in length, and 150 μm in thickness on the surface of the member. One line electrode is an assembly of electrodes in which a plurality of electrodes having an electrode length of 300 μm are arranged at an inter-electrode length of 200 μm in the longitudinal direction of the line electrode. The first member is preferably a glass epoxy substrate.

  Second member: A member having a line electrode 250 μm wide, 2200 μm long and 150 μm thick on the surface of the member body. One line electrode is an assembly of electrodes in which a plurality of electrodes having an electrode length of 300 μm are arranged at an inter-electrode length of 200 μm in the longitudinal direction of the line electrode. The second member is preferably a semiconductor chip.

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

  A member 51 shown in FIG. 7 has electrodes 51 a arranged in a line. The electrode 51a is plural. An assembly 51A of electrodes in which a plurality of electrodes 51a are arranged 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. When the line electrode is a collection of electrodes, the line electrode has a portion with the electrode and a portion without the electrode. In the case where the line electrode is a collection of electrodes, when applying the conductive material 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, a conductive material is applied in the direction of arrow A in FIG.

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

  The viscosity (η 25) at 25 ° C. of the conductive material is preferably 50 Pa · s or more, more preferably 100 Pa · s or more, preferably 800 Pa · s or less, more preferably 600 Pa · s or less. The viscosity (η 25) can be appropriately adjusted according to the type and the amount of the blending component. When the viscosity (η 25) is not less than the lower limit and not more than the upper limit, conduction reliability between the electrodes in the vertical direction can be more effectively enhanced, and insulation reliability between adjacent line electrodes is further enhanced. It can be effectively enhanced.

  The viscosity (η 25) can be measured, for example, at 25 ° C. and 5 rpm using an E-type viscometer (“TVE 22L” manufactured by Toki Sangyo Co., Ltd.) or the like.

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

  The viscosity (η 100) can be measured, for example, using an E-type viscometer (“TVE 22L” manufactured by Toki Sangyo Co., Ltd.) or the like under the conditions of 100 ° C. and 5 rpm.

  The minimum value of the melt viscosity of the conductive material in a temperature range of 140 ° C. or less 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 is there. When the minimum value of the melt viscosity of the conductive material in the temperature range of 140 ° C. or less is the lower limit or more and the upper limit or less, the conduction reliability between the electrodes in the vertical direction can be more effectively enhanced. The insulation reliability between the matching line electrodes can be more effectively enhanced.

  The minimum value of the melt viscosity of the conductive material in a temperature range of 70 ° C. or more and 140 ° C. or less 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 less than or equal to In the temperature range of 70 ° C. or more and 140 ° C. or less, when the minimum value of the melt viscosity of the conductive material is the above lower limit and the above upper limit, the conduction reliability between the electrodes in the vertical direction is more effectively enhanced. Thus, the insulation reliability between adjacent line electrodes can be more effectively enhanced.

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

  The said conductive material can be used as a conductive paste, a conductive film, etc. The conductive paste is preferably an anisotropic conductive paste, and the conductive film is preferably an anisotropic conductive film. From the viewpoint of arranging the solder more efficiently on the electrodes, the conductive material is preferably a conductive paste. The said conductive material is used suitably for the electrical connection of an electrode. The conductive material is preferably a circuit connection material. The conductive material is preferably used for electrical connection of the line electrode. The conductive material is preferably applied in a line form. The conductive material is preferably applied in a line on the line electrode. The line electrode is an electrode arranged in a line. One electrode may be line-shaped, and the line electrode may be one electrode. The plurality of electrodes may be arranged side by side in a line, and the line electrode may be an assembly 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 a conductive material is demonstrated. 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 includes conductive particles. The conductive particles electrically connect the electrodes of the connection target member. The conductive particles preferably have a solder on the outer surface portion of the conductive portion. The conductive particles may be solder particles formed of solder. Both the central portion and the outer surface of the solder particles are formed by solder. The solder particles are particles in which both the central portion and the outer surface are solder. The conductive particles may have base particles and conductive portions disposed on the surface of the base particles. In this case, the conductive particles have solder on the outer surface portion of the conductive portion.

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

  In addition, compared with the case where the said solder particle is used, when using electroconductive particle provided with the base material particle which is not formed by solder, and the solder part arrange | positioned on the surface of this base material particle, It becomes difficult for the conductive particles to collect on the electrode. Furthermore, since the solderability of the conductive particles is low, the conductive particles moved onto the electrodes tend to move to the outside of the electrodes, and the effect of suppressing displacement between the electrodes also tends to be low. Therefore, it is preferable that the said electroconductive particle is a solder particle formed of the solder.

  Next, specific examples 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 for the 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 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 usable for the conductive material.

  The conductive particle 31 shown in FIG. 5 includes a substrate particle 32 and a conductive portion 33 disposed on the surface of the substrate particle 32. The conductive portion 33 covers the surface of the base particle 32. The conductive particle 31 is a coated particle in which the surface of the base particle 32 is covered by 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 particle 32, the second conductive portion 33A disposed on the surface of the base particle 32, and the solder portion 33B disposed on the outer surface of the second conductive portion 33A. And

  FIG. 6 is a cross-sectional view showing a third example of conductive particles usable for the conductive material.

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

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

Base particle:
Examples of the substrate particles include resin particles, inorganic particles other than metal particles, organic-inorganic hybrid particles, metal particles and the like. The substrate particles are preferably substrate 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 comprising a core and a shell disposed on the surface of the core. The core may be an organic core, and the shell may be an inorganic shell.

  The base material 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 results in more suitable conductive particles due to the electrical connection between the electrodes.

  When connecting between electrodes using the said electroconductive particle, after arrange | positioning the said electroconductive particle between electrodes, the said electroconductive particle is compressed by pressure-bonding. When the substrate particles are resin particles or organic-inorganic hybrid particles, the conductive particles are easily deformed during the pressure bonding, and the contact area between the conductive particles and the electrode becomes large. Therefore, the conduction reliability between the electrodes is further enhanced.

  Various resins are suitably used as the material of 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 polymethyl methacrylate and polymethyl acrylate; polyalkylene terephthalates and polycarbonates , Polyamide, phenol formaldehyde resin, melamine formaldehyde resin, benzoguanamine formaldehyde resin, urea formaldehyde resin, phenol resin, melamine resin, melamine resin, benzoguanamine resin, urea resin, epoxy resin, unsaturated polyester resin, saturated polyester resin, polysulfone, polyphenylene oxide, polyacetal, Polyimide, polyamide imide, polyether ether ketone, polyester Terusuruhon, divinylbenzene polymers, divinylbenzene copolymers, and polymers such as obtained by a variety of polymerizable monomer having an ethylenically unsaturated group is polymerized with one or more thereof. Examples of the divinylbenzene-based copolymer include divinylbenzene-styrene copolymer and divinylbenzene- (meth) acrylic acid ester copolymer.

  The material of the resin particle is ethylenic, since resin particles having any compression property suitable for the conductive particles can be designed and synthesized, and the hardness of the substrate particles can be easily controlled to a suitable range. It is preferable that it is a polymer obtained by polymerizing one or two or more kinds of polymerizable monomers having a plurality of saturated groups.

  When the resin particle is obtained by polymerizing a polymerizable monomer having an ethylenically unsaturated group, as the polymerizable monomer having an ethylenically unsaturated group, a non-crosslinkable monomer may be used. And crosslinkable monomers.

  Examples of the non-crosslinkable monomers include styrene-based monomers such as styrene and α-methylstyrene; carboxyl-containing monomers such as (meth) acrylic acid, maleic acid and maleic anhydride; 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 ( Alkyl (meth) acrylate compounds such as meta) acrylate and isobornyl (meth) acrylate; 2-hydroxyethyl (meth) acrylate, glycerol (meth) acrylate, polyoxyethylene (meth) acrylate, glycidyl (meth) acrylate and the like Element-containing (meth) acrylate compounds; nitrile-containing monomers such as (meth) acrylonitrile; acid vinyl ester compounds such as vinyl acetate, vinyl butyrate, vinyl laurate and vinyl stearate; ethylene, propylene, isoprene, butadiene and the like Unsaturated hydrocarbons; halogen-containing monomers such as trifluoromethyl (meth) acrylate, pentafluoroethyl (meth) acrylate, vinyl chloride, vinyl fluoride, chlorostyrene and the like can be mentioned.

  Examples of the crosslinkable monomer include, for example, tetramethylolmethane tetra (meth) acrylate, tetramethylolmethane tri (meth) acrylate, tetramethylolmethane di (meth) acrylate, trimethylolpropane tri (meth) acrylate, and dipentamer. Erythritol 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) Multifunctional (meth) acrylate compounds such as acrylate, (poly) tetramethylene glycol di (meth) acrylate, 1,4-butanediol di (meth) acrylate; triallyl (iso) cyan Silane-containing monomers such as triaryltrimellitate, divinylbenzene, diallyl phthalate, diallylacrylamide, diallyl ether, .gamma .- (meth) acryloxypropyltrimethoxysilane, trimethoxysilylstyrene, vinyltrimethoxysilane, etc. Can be mentioned.

  The said resin particle can be obtained by polymerizing the polymerizable monomer which has the said ethylenically unsaturated group by a well-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 with a radical polymerization initiator using non-crosslinked seed particles.

  When the substrate particles are inorganic particles or organic-inorganic hybrid particles other than metal particles, examples of the inorganic substance that is the material of the substrate particles include silica, alumina, barium titanate, zirconia, carbon black and the like. It is preferable that the said inorganic substance is not a metal. The particles formed of the above silica are not particularly limited. For example, after forming a crosslinked polymer particle by hydrolyzing a silicon compound having two or more hydrolyzable alkoxysilyl groups, baking is carried out as necessary. The particles obtained by carrying out are mentioned. As said organic-inorganic hybrid particle | grains, the organic-inorganic hybrid particle | grains etc. which were formed, for example by bridge | crosslinking alkoxy silyl polymer and acrylic resin are mentioned.

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

  As a material of the said organic core, the material of the resin particle mentioned above, etc. are mentioned.

  As a material of the said inorganic shell, the inorganic substance mentioned as a material of the base material particle mentioned above is mentioned. The material of the inorganic shell is preferably silica. The inorganic shell is preferably formed on the surface of the core by forming a metal alkoxide into a shell by a sol-gel method and then firing the shell. The metal alkoxide is preferably a silane alkoxide. The inorganic shell is preferably formed of a silane alkoxide.

  When the base particle is a metal particle, examples of the metal that is the material of the metal particle include silver, copper, nickel, silicon, gold and titanium.

  The particle diameter of the base particle 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 diameter of the base particle is equal to or more than the above lower limit, the contact area between the conductive particle and the electrode is increased, so that the conduction reliability between the electrodes is further enhanced, and connection is made via the conductive particle. The connection resistance between the electrodes can be further effectively reduced. Furthermore, when forming a conductive part on the surface of a substrate particle, it becomes difficult to aggregate, and it becomes difficult to form aggregated conductive particles. When the particle diameter of the base particle is equal to or less than the above upper limit, the conductive particles are easily compressed sufficiently, and the connection resistance between the electrodes connected via the conductive particles is further effectively reduced. it can.

  The particle diameter of the base particle is particularly preferably 5 μm or more and 40 μm or less. When the particle diameter of the base particle is in the range of 5 μm to 40 μm, the distance between the electrodes can be further reduced, and small conductive particles can be obtained even if the thickness of the conductive portion is increased. be able to.

  The particle diameter of the substrate particle indicates a diameter when the substrate particle is spherical, and indicates a maximum diameter when the substrate particle is not spherical.

  The particle diameter of the base particle is preferably an average particle diameter, and more preferably a number average particle diameter. The particle diameter of the substrate particles can be determined using a particle size distribution measuring device or the like. The particle diameter of the substrate particles is preferably determined by observing 50 arbitrary substrate particles with an electron microscope or an optical microscope and calculating an average value. In the case of measuring the particle diameter of the above-mentioned base material particle in the conductive particle, it can be measured, for example, as follows.

  It is added to "Technobit 4000" manufactured by Kulzer, and dispersed so that the content of the conductive particles is 30% by weight, and a conductive particle inspection embedded resin is produced. The cross section of the conductive particles is cut out using an ion milling apparatus ("IM 4000" 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 25000 times, 50 conductive particles are randomly selected, and the substrate particles of each conductive particle are observed. Do. The particle size of the base material particles in each conductive particle is measured, and arithmetic mean of them is made to be the particle size of the base material particles.

Conductive part:
The method of forming a conductive portion on the surface of the base particle and the method of forming a solder portion on the surface of the base particle or the surface of the second conductive portion are not particularly limited. As the method of forming the conductive portion and the solder portion, for example, a method by electroless plating, a method by electroplating, a method by physical collision, a method by mechanochemical reaction, a method by physical vapor deposition or physical adsorption, And a method of coating a metal powder or a paste containing a metal powder and a binder on the surface of a substrate particle, and the like. The method of 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 methods such as vacuum deposition, ion plating and ion sputtering. Further, in the method based on the physical collision, for example, a theta composer (manufactured by Tokuju Craft Co., Ltd.) or the like is used.

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

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

  It is preferable that the said solder is a metal (low melting metal) whose melting | fusing point is 450 degrees C or less. The solder portion is preferably a metal layer (low melting point metal layer) having a melting point of 450 ° C. or less. 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 (low melting point metal particles) having a melting point of 450 ° C. or less. 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 less. The melting point of the low melting point metal is preferably 300 ° C. or less, more preferably 160 ° C. or less. The solder particles are preferably low melting point solder having a melting point of less than 150.degree.

  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 a differential scanning calorimetry (DSC) apparatus include "EXSTAR DSC 7020" manufactured by SII.

  Moreover, it is preferable that the solder in the said electroconductive particle contains a tin. The content of tin is preferably 30% by weight or more, more preferably 40% by weight or more, more preferably 100% by weight of the metal contained in the solder portion and 100% by weight of the metal contained in the solder of 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 particle is equal to or more than the lower limit, the conduction reliability between the conductive particle and the electrode is further enhanced.

  The content of tin is determined using a high-frequency inductively coupled plasma emission spectrometer ("ICP-AES" manufactured by Horiba, Ltd.) or a fluorescent X-ray analyzer ("EDX-800HS" manufactured by Shimadzu Corporation). It can be measured.

  By using the conductive particles having the above-described solder on the outer surface portion of the conductive portion, the solder is melted and joined to the electrodes, and the solder brings the electrodes into conduction. For example, since the solder and the electrode are likely to be in surface contact rather than point contact, connection resistance is lowered. In addition, the use of conductive particles having solder on the outer surface portion of the conductive part increases the bonding strength between the solder and the electrode. As a result, peeling between the solder and the electrode is more difficult to occur, and conduction reliability is effective. Become high.

  The low melting point metal which comprises the said solder part and the said solder is not specifically 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, and tin-indium alloy. The low melting point metal is preferably tin, a tin-silver alloy, a tin-silver-copper alloy, a tin-bismuth alloy, or a tin-indium alloy because the wettability to the electrode is excellent. More preferably, tin-bismuth alloy or tin-indium alloy is used.

  It is preferable that the material which comprises the said solder (solder part) is a filler material whose liquidus line is 450 degrees C or less based on JISZ3001: welding term. Examples of the composition of the solder include metal compositions containing zinc, gold, silver, lead, copper, tin, bismuth, indium and the like. Low melting point and lead-free tin-indium (117 ° C eutectic) or tin-bismuth (139 ° C eutectic) is preferable. That is, the solder is preferably free of 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 portion or the conductive particle, the solder in the conductive particle is preferably nickel, copper, antimony, aluminum, zinc, iron, gold, titanium, phosphorus, germanium, tellurium It may contain metals such as cobalt, bismuth, manganese, chromium, molybdenum and palladium. Further, from the viewpoint of further increasing the bonding strength between the solder and the electrode in the solder portion or the conductive particle, the solder in the conductive particle preferably contains nickel, copper, antimony, aluminum or zinc. From the viewpoint of further enhancing the bonding strength between the solder and the electrode in the solder portion or the conductive particles, the content of these metals for enhancing the bonding strength is preferably 0% in 100% by weight of the solder in the conductive particles. .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 part is preferably more than 160 ° C., more preferably more than 300 ° C., still more preferably more than 400 ° C., still more preferably more than 450 ° C., particularly preferably more than 500 ° C. Most preferably, it exceeds 600 ° C. The solder portion melts at the time of conductive connection because the melting point is low. 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 a solder, preferably by melting the solder portion, and used without melting the solder portion and the second conductive portion. Being preferred. When 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 is more than 0 ° C., preferably 5 ° C. or more, more preferably 10 ° C. or more, still more preferably 30 ° C. or more, particularly preferably Is 50.degree. C. or higher, most preferably 100.degree. C. or higher.

  The second conductive portion preferably contains a metal. The metal which comprises the said 2nd electroconductive part is not specifically 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. Alternatively, tin-doped indium oxide (ITO) may be used as the metal. The metal may be used alone or in combination of two or more.

  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 still more preferably a copper layer. The conductive particles preferably have 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 still more preferably a copper layer. By using conductive particles having these preferred conductive portions for connection between electrodes, connection resistance between the electrodes is further reduced. In addition, solder portions can be more easily formed on the surfaces of these preferred 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, and 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 is obtained, and the conductive particles are sufficiently deformed at the time of connection between the electrodes without the conductive particles becoming too hard. Do.

  The particle diameter 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, particularly preferably 40 μm or less. The solder in the conductive particles can be arranged more efficiently on the electrodes when the particle diameter of the conductive particles is not less than the lower limit and not more than the upper limit, and many solders in the conductive particles can be disposed between the electrodes It is easy to arrange, and the conduction reliability is further enhanced.

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

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

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

  CV value (%) = (ρ / Dn) × 100

ρ: Standard deviation of particle diameter of conductive particles Dn: Average value of particle diameters 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 flat or other non-spherical shape.

  The content of the conductive particles 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 100% by weight of the conductive material. It is 30% by weight or more, preferably 80% by weight or less, more preferably 60% by weight or less, and still more preferably 50% by weight or less. When the content of the conductive particles is not less than the lower limit and not more than the upper limit, the conductive particles can be disposed more efficiently on the electrode, and a large amount of conductive particles can be disposed between the electrodes. It is easy and the conduction reliability is further enhanced. 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, and may contain a thermosetting agent. In order to cure the conductive material better, the thermosetting component preferably contains a thermosetting compound and a thermosetting agent. In order to cure the conductive material better, the thermosetting component preferably contains a curing accelerator.

(Thermosetting component: Thermosetting compound)
The said thermosetting compound is not specifically 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 enhancing the conduction reliability between the electrodes in the vertical direction more effectively, and further enhancing the insulation reliability between the adjacent line electrodes more effectively. From the viewpoint, an epoxy compound or an episulfide compound is preferable, and an epoxy compound is more preferable.

  It is preferable that the said thermosetting compound contains an epoxy compound. Only one type of the thermosetting compound may be used, or two or more types may be used in combination.

  The epoxy compound is a compound having at least one epoxy group. Examples of the epoxy compounds include bisphenol A type epoxy compounds, bisphenol F type epoxy compounds, bisphenol S type epoxy compounds, phenol novolac type epoxy compounds, biphenyl type epoxy compounds, biphenyl novolac type epoxy compounds, biphenol type epoxy compounds, naphthalene type epoxy compounds , Fluorene type epoxy compounds, phenol aralkyl type epoxy compounds, naphthol aralkyl type epoxy compounds, dicyclopentadiene type epoxy compounds, anthracene type epoxy compounds, epoxy compounds having an adamantane skeleton, epoxy compounds having a tricyclodecane skeleton, naphthalene ether type The epoxy compound, the epoxy compound which has a triazine nucleus in frame | skeleton, etc. are mentioned. Only one type of the epoxy compound may be used, or two or more types may be used in combination.

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

  From the viewpoint of more effectively enhancing the conduction reliability between the electrodes in the vertical direction and the viewpoint of enhancing the insulation reliability between the adjacent line electrodes more effectively, the thermosetting compound contains an epoxy compound. Is preferred.

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

  From the viewpoint of more effectively improving the heat resistance of the cured product, the thermosetting compound preferably contains a thermosetting compound having an isocyanuric skeleton.

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

  The content of the thermosetting compound is preferably 20% by weight or more, more preferably 40% by weight or more, still more preferably 50% by weight or more, and preferably 99% by weight or less in 100% by weight of the conductive material. It is preferably at most 98 wt%, more preferably at most 90 wt%, particularly preferably at most 80 wt%. When the content of the thermosetting compound is not less than the lower limit and not more than the upper limit, the conductive particles can be arranged more efficiently on the electrode. When the content of the thermosetting compound is at least the lower limit and the upper limit, the conduction reliability between the electrodes in the vertical direction can be more effectively enhanced, and the insulation reliability between the adjacent line electrodes is achieved. Can be enhanced more effectively. From the viewpoint of more effectively improving the impact resistance, the content of the thermosetting compound is preferably as large as possible.

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

(Thermosetting component: thermosetting agent)
The said thermosetting agent is not specifically limited. The thermosetting agent thermally cures the thermosetting compound. Examples of the thermosetting agent include imidazole curing agents, amine curing agents, phenol curing agents, thiol curing agents such as polythiol curing agents, acid anhydride curing agents, thermal cation initiators (thermal cationic curing agents), thermal radical generating agents, etc. 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 rapidly at low temperature, the heat curing 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 polymeric substance such as a polyurethane resin or a polyester resin.

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

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

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

  The above-mentioned acid anhydride curing agent is not particularly limited, and any acid anhydride may be used widely as long as it is used as a curing agent for thermosetting compounds such as epoxy compounds. As the above acid anhydride curing agent, phthalic anhydride, tetrahydrophthalic anhydride, trialkyltetrahydrophthalic anhydride, hexahydrophthalic anhydride, methylhexahydrophthalic anhydride, methyltetrahydrophthalic anhydride, methylbutenyltetrahydrophthalic anhydride , Anhydrides of phthalic acid derivatives, maleic anhydride, nadic acid anhydride, methyl nadic acid anhydride, glutaric acid anhydride, succinic acid anhydride, glycerin bis trimellitic anhydride monoacetate, and difunctional ethylene glycol bis trimellitic anhydride, etc. Acid anhydride curing agents, trifunctional acid anhydride curing agents such as trimellitic anhydride, and pyromellitic anhydride, benzophenone tetracarboxylic acid anhydride, methylcyclohexene tetracarboxylic acid anhydride, polyazelaic acid anhydride, etc. Acidic anhydride of 4 or more functional Curing agents.

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

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

  The reaction initiation temperature of the thermosetting agent is preferably 50 ° C. or more, more preferably 70 ° C. or more, still more preferably 80 ° C. or more, preferably 250 ° C. or less, more preferably 200 ° C. or less, still more preferably 150 ° C. The temperature is particularly preferably 140 ° C. or less. When the reaction initiation temperature of the thermosetting agent is above the lower limit and below the upper limit, the conductive particles are more efficiently disposed on the electrode. The reaction initiation temperature of the thermosetting agent is particularly preferably 80 ° C. or more and 140 ° C. or less.

  From the viewpoint of arranging the conductive particles more efficiently on the electrode, the reaction initiation temperature of the thermosetting agent is preferably higher than the melting point of the solder in the conductive particles, and higher by 5 ° C. or more Preferably, the temperature is higher by 10 ° C. or more.

  The reaction initiation temperature of the thermosetting agent means the temperature at which the onset of the onset of the exothermic peak in DSC.

  The content of the thermosetting agent is not particularly limited. The content of the thermosetting agent is preferably 0.01 parts by weight or more, more preferably 1 part by weight or more, and preferably 200 parts by weight or less, more preferably 100 parts by weight of the thermosetting compound. It is 100 parts by weight or less, more preferably 75 parts by weight or less. It is easy to fully harden a conductive material as content of a thermosetting agent is more than the above-mentioned minimum. When the content of the thermosetting agent is less than or equal to the above upper limit, it becomes difficult for the surplus thermosetting agent that did not participate in curing to remain after curing, and the heat resistance of the cured product is further enhanced.

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

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

  The phosphonium salt is not particularly limited. Examples of the phosphonium salt include tetranormal butyl phosphonium bromide, tetra normal butyl phosphonium OO diethyl dithiophosphate, methyl tributyl phosphonium dimethyl phosphate, tetra normal butyl phosphonium benzotriazole, tetra normal butyl phosphonium tetrafluoroborate, and tetra normal butyl Examples include phosphonium tetraphenyl borate and the like.

  The content of the curing accelerator is appropriately selected so that the thermosetting compound cures satisfactorily. The content of the curing accelerator relative 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, more preferably 6 parts by weight It is below. The said thermosetting compound can be favorably hardened as content of the said hardening accelerator is more than the said minimum and below the said upper limit.

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

  Examples of the flux include zinc chloride, a mixture of zinc chloride and an inorganic halide, a mixture of zinc chloride and an inorganic acid, a molten salt, phosphoric acid, a derivative of phosphoric acid, an organic halide, a hydrazine, an amine compound, an organic acid and Matsusebo, etc. may be mentioned. The flux may be used alone or in combination of two or more.

  Ammonium chloride etc. are mentioned as said molten salt. Examples of the organic acids include lactic acid, citric acid, stearic acid, glutamic acid and glutaric acid. Examples of the rosin include activated rosin and non-activated rosin. The flux is preferably an organic acid having two or more carboxyl groups, or rosin. The flux may be an organic acid having two or more carboxyl groups, or may be rosin. The use of an organic acid having two or more carboxyl groups, or rosin, further enhances the conduction reliability 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 above amine compound include cyclohexylamine, dicyclohexylamine, benzylamine, benzhydrylamine, imidazole, benzimidazole, phenylimidazole, carboxybenzimidazole, benzotriazole, carboxybenzotriazole and the like.

  The above-mentioned rosins are rosins mainly composed of abietic acid. Examples of the rosins include abietic acid and acrylic modified rosin. The flux is preferably rosins, more preferably abietic acid. The use of this preferred flux further enhances the conduction reliability between the electrodes.

  The activation temperature (melting point) of the flux is preferably 50 ° C. or more, more preferably 70 ° C. or more, still more preferably 80 ° C. or more, preferably 200 ° C. or less, more preferably 190 ° C. or less, still more preferably 160 Or less, more preferably 150 ° C. or less, still more preferably 140 ° C. or less. When the activation temperature of the flux is above the lower limit and below the upper limit, the flux effect is more effectively exhibited, and the conductive particles are arranged more efficiently on the electrode. The activation temperature (melting point) of the flux is preferably 80 ° C. or more and 190 ° C. or less. The activation temperature (melting point) of the flux is particularly preferably 80 ° C. or more and 140 ° C. or less.

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

  Moreover, it is preferable that the boiling point of the said flux is 200 degrees C or less.

  From the viewpoint of arranging the conductive particles more efficiently on the electrode, the melting point of the flux is preferably higher than the melting point of the solder in the conductive particle, and more preferably 5 ° C. or more, 10 It is further preferable that the temperature is higher by at least ° C.

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

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

  When 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 in the electrode portion. This is because, when heat is applied at the time of bonding, the thermal conductivity of the electrode portion is equal to that of the connection target member portion when comparing the electrode formed on the connection target member and the connection target member portion around the electrode. The higher temperature than the thermal conductivity is attributed to the rapid temperature rise of the electrode portion. When the conductive particle exceeds the melting point of the solder, the solder portion of the conductive particle dissolves, but the oxide film formed on the surface is not removed because it does not reach the melting point (activation temperature) of the flux. In this state, since the temperature of the electrode portion first reaches the melting point (activation temperature) of the flux, the oxide film on the surface of the conductive particles moved preferentially onto the electrode is removed, and the solder in the conductive particles becomes the electrode Can spread on the surface of the Thereby, conductive particles can be efficiently aggregated on the electrode.

  It is preferable that the said flux is a flux which discharge | releases a cation by heating. The use of a flux that releases cations upon heating allows the conductive particles to be placed more efficiently on the electrode.

  As a flux which releases a cation by the above-mentioned heating, the above-mentioned heat cation initiator (heat cation hardening agent) is mentioned.

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

  The acid compound is preferably an organic compound having a carboxyl group. Examples of the acid compound include malonic acid which is an aliphatic carboxylic acid, succinic acid, glutaric acid, adipic acid, pimelic acid, suberic acid, azelaic acid, sebacic acid, citric acid, malic acid and cycloaliphatic carboxylic acid Examples thereof include cyclohexylcarboxylic acid, 1,4-cyclohexyldicarboxylic acid, isophthalic acid which is an aromatic carboxylic acid, terephthalic acid, trimellitic acid, and ethylenediaminetetraacetic acid. From the viewpoint of more efficiently arranging the conductive particles on the electrode, the viewpoint of enhancing the insulation reliability more effectively, and the viewpoint of enhancing the conduction reliability more effectively, the above-mentioned acid compound is And cyclohexylcarboxylic acid or adipic acid.

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

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

  It is preferable that the conductive material does not contain the filler, or contains 5% by weight or less of the filler. When the above-mentioned thermosetting compound is used, the smaller the filler content, the easier the solder particles move on the electrode.

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

(Other ingredients)
The conductive material may optionally contain, for example, fillers, extenders, softeners, plasticizers, thickeners, thickeners, thixo agents, leveling agents, polymerization catalysts, curing catalysts, colorants, antioxidants, heat stabilizers Various additives such as light stabilizers, UV absorbers, lubricants, antistatic agents and flame retardants may be included.

(Connection structure and manufacturing method of connection structure)
A 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. And a connecting portion connecting the second connection target member. In the connection structure according to the present invention, the material of the connection portion is the above-described 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. The first electrode and the second electrode are preferably arranged in a line.

  In a specific aspect, a method of manufacturing a connection structure according to the present invention includes: forming a line of the first electrode on a surface of a first connection target member having a first electrode arranged in a line on the surface; And the step of applying the conductive material described above in a line. In the method of manufacturing a connection structure according to the present invention, a second connection having on the surface a second electrode arranged in a line on the surface of the conductive material opposite to the first connection target member side is provided. And disposing the target member such that the first electrode and the second electrode face each other. In the method of manufacturing a connection structure according to the present invention, the connection portion connecting the first connection target member and the second connection target member by heating the conductive material is made of the conductive material. Forming and electrically connecting the first electrode and the second electrode with the conductive particles.

  In a specific aspect, a method of manufacturing a connection structure according to the present invention includes: forming a line of the first electrode on a surface of a first connection target member having a first electrode arranged in a line on the surface; Along a line, a conductive material including a thermosetting component and a thermosetting agent is applied in a line. In the method of manufacturing a connection structure according to the present invention, a second connection having on the surface a second electrode arranged in a line on the surface of the conductive material opposite to the first connection target member side is provided. And an arranging step of arranging the target member such that the first electrode and the second electrode face each other. In the method of manufacturing a connection structure according to the present invention, the connection portion connecting the first connection target member and the second connection target member by heating the conductive material is made of the conductive material. And a connecting step of electrically connecting the first electrode and the second electrode with the conductive particles. In the method for manufacturing a connection 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 Xa1, and the heating of the conductive material is started to 100 ° C. When the width of the conductive material at the time of reaching is Xa2, Xa2 is made 1.25 times or less of Xa1. In other words, in the method of 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 of manufacturing a connection structure according to the present invention, it is preferable to start heating from a temperature of 40 ° C. or less.

  The connection structure and the method of manufacturing the connection structure according to the present invention, having the above-described configuration, can effectively enhance the conduction reliability between the electrodes in the vertical direction, and between adjacent line electrodes. 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 to efficiently connect electrodes. According to the present invention, even in the connection between line electrodes, the conduction reliability between the electrodes in the vertical direction to be connected can be effectively improved. Furthermore, in the case where there are a plurality of line electrodes adjacent in the lateral direction, insulation reliability between the adjacent line electrodes can be effectively enhanced.

  In the present invention, in order to obtain the effects as described above, adopting a specific connection structure manufacturing process greatly contributes.

  The ratio of Xa2 to Xa1 (Xa2 / Xa1) is 1.25 or less. The ratio (Xa2 / Xa1) is preferably 1.20 or less, more preferably 1.10 or less. The lower limit of the ratio (Xa2 / Xa1) is not particularly limited. The ratio (Xa2 / Xa1) may be 1.01 or more. When the ratio (Xa2 / Xa1) is equal to or more than the lower limit and equal to or less than the upper limit, the conduction reliability between the electrodes in the vertical direction can be more effectively enhanced, and the insulation reliability between adjacent line electrodes can be increased. It can be enhanced 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 more effectively enhancing the conduction reliability between the electrodes in the vertical direction and the viewpoint of enhancing the insulation reliability between the adjacent line electrodes more effectively, the width Xa1 is preferably 150 μm or more, and more preferably Preferably it is 200 micrometers or more, Preferably it is 300 micrometers or less, More preferably, it is 275 micrometers or less.

  From the viewpoint of more effectively enhancing the conduction reliability between the electrodes in the vertical direction and the viewpoint of enhancing the insulation reliability between the adjacent line electrodes more effectively, the length Ya1 is preferably at least 1000 μm, More preferably, it is 1500 micrometers or more, Preferably it is 4000 micrometers or less, More preferably, it is 3000 micrometers or less.

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

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

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

  Further, in order to efficiently dispose the conductive particles on the electrode and considerably reduce the amount of the conductive particles disposed in the region where the electrode is not formed, the conductive material is not 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, more preferably 80 μm or less. The solder wet area on the surface of the electrode (the area in contact with the solder in 100% of the exposed area of the electrode) is preferably 50% or more, more preferably 70% or more, and preferably 100% or less.

  In the method of manufacturing a connection structure according to the present invention, no pressure is applied in the step of arranging the second connection target member and the step of forming the connection portion, and the second connection is performed on the conductive material. Preferably, the weight of the target member is added. In the method of 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 controlled by the force of the weight of the second connection target member. Preferably, no overpressure 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 further effectively increased, and a large number of conductive particles are easily collected between the electrodes, and the efficiency of the conductive particles on the electrodes (lines) is further enhanced. Can be arranged. In addition, a part of the plurality of conductive particles is difficult to be disposed in the region (space) in which the electrode is not formed, and the amount of the conductive particles disposed in the region in which the electrode is not formed is further reduced. it can. Therefore, the conduction reliability between the electrodes can be further enhanced. Moreover, the electrical connection between the laterally adjacent line electrodes, which should not be connected, can be further prevented, and the insulation reliability can be further enhanced.

  In addition, if the conductive paste is used instead of the conductive film, the thickness of the connection portion and the solder portion can be easily adjusted by the application amount of the conductive paste. On the other hand, in the case of the conductive film, in order to change or adjust the thickness of the connection portion, it is necessary to prepare conductive films having different thicknesses or to prepare conductive films having a predetermined thickness. There is. In addition, the conductive film can not sufficiently lower the melt viscosity of the conductive film as compared with the conductive paste, and the aggregation of the conductive particles tends to be inhibited.

  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 a conductive material according to an embodiment of the present invention.

  The connection structure 1 shown in FIG. 1 is a connection in which the first connection target member 2, the second connection target member 3, and the first connection target member 2 and the second connection target member 3 are connected. And 4 are provided. The connection portion 4 is formed of the above-described conductive material. In the present embodiment, the conductive material includes a thermosetting component and conductive particles. In the present embodiment, solder particles are used as the conductive particles. In the present embodiment, a conductive paste is used as the conductive material.

  The connection portion 4 includes a solder portion 4A in which a plurality of solder particles are gathered and joined together, 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, the plurality of first electrodes 2 a are arranged side by side in the left-right direction. The linear first electrode 2a (line electrode) is an assembly 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 3 a are arranged side by side in the left-right direction. The linear second electrode 3a (line electrode) is an assembly 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 connection portion 4, solder particles do not exist in a region (hardened portion 4 B portion) different from the solder portion 4 A gathered between the first electrode 2 a and the second electrode 3 a. In a region (hardened portion 4B portion) different from the solder portion 4A, there is no solder particle separated from the solder portion 4A. If the amount is small, solder particles may be present in a region (hardened portion 4B portion) different from the solder portion 4A collected between the first electrode 2a and the second electrode 3a.

  As shown in FIG. 1, in the connection structure 1, a plurality of solder particles gather between the first electrode 2 a and the second electrode 3 a, and after the plurality of solder particles are melted, a melt of the solder particles After the surface of the electrode is wetted and spread, it is solidified to form a solder portion 4A. Therefore, the connection area between the solder portion 4A and the first electrode 2a, and between the solder portion 4A and the second electrode 3a is increased. That is, by using the solder particles, the solder portion 4A, the first electrode 2a, and the solder portion are compared to the case where the conductive outer surface is a metal such as nickel, gold or copper. The contact area between 4A and the second electrode 3a is increased. This also increases the conduction reliability and the connection reliability in the connection structure 1. In the case where the conductive material contains a flux, the flux is generally gradually inactivated by heating.

  In the connection structure 1 shown in FIG. 1, all of the solder portions 4A are located in the area where the first and second electrodes 2a and 3a are facing each other. The connection structure 1X of the modified example shown in FIG. 3 differs from the connection structure 1 shown in FIG. 1 only in the connection part 4X. The connection portion 4X has a solder portion 4XA and a cured product portion 4XB. As in 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 portions. It may be protruded to the side from the field which electrode 2a, 3a has opposed. The solder portion 4XA protruding to the side from the opposing region 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 the present embodiment, the amount of solder particles separated from the solder portion can be reduced, but solder particles separated from the solder portion may be present in the cured product portion.

  The connection structure 1 can be easily obtained by reducing the amount of solder particles used. The connection structure 1X can be easily obtained by increasing the amount of solder particles used.

  In the connection structures 1 and 1X, when the first electrode 2a and the second electrode 3a face each other in the stacking direction of the first electrode 2a, the connection portions 4 and 4X, and the second electrode 3a. Preferably, the solder portions 4A and 4XA in the connection portions 4 and 4X are arranged in 50% or more of the area 100% of the opposing portions 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-described preferred embodiments, the conduction reliability can be further enhanced.

  When the portion where the first electrode and the second electrode face each other is viewed in the stacking direction of the first electrode, the connection portion, and the second electrode, the first electrode and the It is preferable that the solder part in the said connection part is arrange | positioned in 50% or more in 100% of the area of the part which opposes 2 electrodes. When the portion where the first electrode and the second electrode face each other is viewed in the stacking direction of the first electrode, the connection portion, and the second electrode, the first electrode and the It is more preferable that the solder part in the said connection part is arrange | positioned in 60% or more in 100% of area of the part which opposes 2 electrodes. When the portion where the first electrode and the second electrode face each other is viewed in the stacking direction of the first electrode, the connection portion, and the second electrode, the first electrode and the It is further preferable that the solder portion in the connection portion be disposed at 70% or more in 100% of the area of the portion facing the two electrodes. When the portion where the first electrode and the second electrode face each other is viewed in the stacking direction of the first electrode, the connection portion, and the second electrode, the first electrode and the It is particularly preferable that the solder portion in the connection portion be disposed at 80% or more of the area 100% of the portion facing the two electrodes. When the portion where the first electrode and the second electrode face each other is viewed in the stacking direction of the first electrode, the connection portion, and the second electrode, the first electrode and the It is most preferable that the solder portion in the connection portion be disposed in 90% or more of the area 100% of the portion facing the two electrodes. The conduction reliability can be further enhanced by the solder portion in the connection portion satisfying the above-described preferred embodiment.

  When the portion where the first electrode and the second electrode face each other in a direction orthogonal to the stacking direction of the first electrode, the connection portion, and the second electrode is viewed, the first It is preferable that 60% or more of the solder portion in the connection portion be disposed at a portion where the electrode and the second electrode face each other. When the portion where the first electrode and the second electrode face each other in a direction orthogonal to the stacking direction of the first electrode, the connection portion, and the second electrode is viewed, the first It is more preferable that 70% or more of the solder portion in the connection portion be disposed at a portion where the electrode and the second electrode face each other. When the portion where the first electrode and the second electrode face each other in a direction orthogonal to the stacking direction of the first electrode, the connection portion, and the second electrode is viewed, the first It is further preferable that 90% or more of the solder portion in the connection portion be disposed at a portion where the electrode and the second electrode face each other. When the portion where the first electrode and the second electrode face each other in a direction orthogonal to the stacking direction of the first electrode, the connection portion, and the second electrode is viewed, the first It is particularly preferable that 95% or more of the solder portion in the connection portion be disposed at a portion where the electrode and the second electrode face each other. When the portion where the first electrode and the second electrode face each other in a direction orthogonal to the stacking direction of the first electrode, the connection portion, and the second electrode is viewed, the first It is most preferable that 99% or more of the solder portion in the connection portion be disposed at a portion where the electrode and the second electrode face each other. The conduction reliability can be further enhanced by the solder portion in the connection portion satisfying the above-described preferred embodiment.

  Next, FIG. 2 demonstrates an example of the method of manufacturing the connection structure 1 using the electrically-conductive material which concerns on one Embodiment of this 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 including 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 ((1) First step, coating step). The used conductive material 11 contains a thermosetting compound and a thermosetting agent as the thermosetting component 11B.

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

  The method of arranging the conductive material 11 is not particularly limited, but application by a dispenser, screen printing, discharge by an inkjet device, etc. may be mentioned.

  In addition, the second connection target member 3 having the second electrodes 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 on the opposite side 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 disposed on the surface of the conductive material 11 from the second electrode 3 a side. At this time, the first electrode 2a and the second electrode 3a are made to face each other.

  Next, the conductive material 11 is heated to the melting point or more of the solder particles 11A (third step, connection step). Preferably, the conductive material 11 is heated to a temperature higher than the curing temperature of the thermosetting component 11B (thermosetting compound). At the time of this heating, the solder particles 11A present in the region where the electrode is not formed gather between the first electrode 2a and the second electrode 3a (self-aggregation effect). When the conductive paste is used instead of the conductive film, the solder particles 11A gather more effectively between the first electrode 2a and the second electrode 3a. Also, the solder particles 11A melt and bond to each other. In addition, the thermosetting component 11B is thermally cured. As a result, as shown in FIG. 2C, the connection portion 4 connecting the first connection target member 2 and the second connection target member 3 is formed of the conductive material 11. The connection portion 4 is formed of the conductive material 11, and 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 movement of the solder particles 11A not located between the first electrode 2a and the second electrode 3a starts, and then the first electrode 2a and the second electrode It is not necessary to keep the temperature constant until the movement of the solder particles 11A is completed between 3a and 3a.

  In the present embodiment, it is preferable not to apply pressure 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, at the time of formation of the connection portion 4, the solder particles 11A are more effectively gathered between the first electrode 2a and the second electrode 3a. When pressing is performed in at least one of the second step and the third step, the solder particles 11A act 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 alignment between the first electrode 2a and the second electrode 3a is shifted. Even when they are superimposed, the deviation can be corrected to connect the first electrode 2a and the second electrode 3a (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 same as the solder between the first electrode 2a and the second electrode 3a and the other conductive material. Since the direction in which the area in contact with the component is the smallest becomes energetically stable, a force acts on the connection structure having alignment that is the connection structure having the smallest area. 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, more preferably 0 .2 Pa · s or more. If the said viscosity is below the said upper limit, solder particle | grains can be aggregated efficiently. If the said viscosity is more than the said minimum, the void in a connection part can be suppressed and the protrusion of the electrically-conductive material to other than a connection part can be suppressed.

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

  Thus, the connection structure 1 shown in FIG. 1 is obtained. The second step and the third step may be performed continuously. Moreover, after performing the said 2nd process, the laminated body of the 1st connection object member 2, the conductive material 11, and the 2nd connection object member 3 obtained is moved to a heating part, and said 3rd A process may be performed. In order to perform the heating, the laminate may be disposed on a heating member, or the laminate may be disposed in a heated space.

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

  As a heating method in the third step, a method of heating the entire connection structure by using a reflow furnace or using an oven at a temperature higher than the melting point of the solder particles and higher than the curing temperature of the thermosetting component There is a method of locally heating only the body connection.

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

  In addition, when heating locally with a hot plate, the metal directly under the connection should be a metal with high thermal conductivity, and other parts where heating is not desirable should be a material with low thermal conductivity such as fluorocarbon resin. Preferably, the upper surface of the hot plate is formed.

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

  It is preferable that at least one of the first connection target member and the second connection target member is a resin film, a flexible printed board, a flexible flat cable, or a rigid flexible board. It is preferable that the said 2nd connection object member is a resin film, a flexible printed circuit board, a flexible flat cable, or a rigid flexible substrate. The resin film, the flexible printed circuit, the flexible flat cable and the rigid flexible substrate have properties of high flexibility and relatively light weight. When a conductive film is used to connect such a connection target member, the solder particles tend to be difficult to collect on the electrode. On the other hand, by using a conductive paste, even if a resin film, a flexible printed board, a flexible flat cable, or a rigid flexible board is used, the solder particles are efficiently collected on the electrodes, so that the conduction reliability between the electrodes is achieved. It is possible to improve sexuality sufficiently. When using a resin film, a flexible printed board, a flexible flat cable, or a rigid flexible board, compared with the case of using other connection target members such as a semiconductor chip, reliability of conduction between electrodes by not applying pressure The improvement effect can be obtained more effectively.

  As an electrode provided in the said connection object member, metal electrodes, such as a gold electrode, a nickel electrode, a tin electrode, an aluminum electrode, a copper electrode, a molybdenum electrode, a silver electrode, a SUS electrode, and a tungsten electrode, are mentioned. When the connection target member is a flexible printed circuit, the electrode is preferably a gold electrode, a nickel electrode, a tin electrode, a silver electrode or a copper electrode. When the connection target member is a glass substrate, the electrode is preferably an aluminum electrode, a copper electrode, a molybdenum electrode, a silver electrode or a tungsten electrode. In addition, when the said electrode is an aluminum electrode, the electrode formed only with aluminum may be sufficient, and the electrode by which the aluminum layer was laminated | stacked on the surface of a metal oxide layer may be sufficient. As a material of the said metal oxide layer, the indium oxide in which the trivalent metal element was doped, the zinc oxide in which the trivalent metal element was doped, etc. are mentioned. Sn, Al, Ga, etc. are mentioned as said trivalent metal element.

  In the connection structure according to the present invention, the first electrode and the second electrode are preferably arranged in an area array or a peripheral. When the first electrode and the second electrode are arranged in an area array or 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 on the surface on which the electrodes of the connection target member are arranged. The peripheral is a structure in which an electrode is disposed on the outer peripheral portion of the connection target member. In the case of the structure in which the electrodes are arranged in a comb shape, the conductive particles may be aggregated along the direction perpendicular to the combs, whereas in the area array or peripheral structure, in the surface on which the electrodes are arranged, It is necessary for the conductive particles to be uniformly aggregated over the entire surface. Therefore, in the conventional method, the amount of the conductive particles is likely to be nonuniform, 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 by way of examples and comparative examples. The invention is not limited to the following examples.

Thermosetting Component (Thermosetting Compound):
Thermosetting compound 1: Novolak type epoxy compound, "Don 431" manufactured by The Dow Chemical Company
Thermosetting compound 2: Dicyclopentadiene type epoxy compound, "HP7200HH" manufactured by DIC

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

Thermosetting component (hardening accelerator):
Hardening accelerator 1: "PX-4MP" manufactured by Nippon Chemical Industry Co., Ltd.

flux:
Flux 1: "benzyl glutarate salt", melting point 108 ° C

How to make 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 placed and dissolved until uniform at room temperature. Thereafter, 10.715 g of benzylamine (manufactured by Wako Pure Chemical Industries, Ltd.) was added, and the mixture was stirred for about 5 minutes to obtain a mixed solution. The resulting mixture was placed in a 5-10 ° C refrigerator 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 obtained by sorting “Sn 42 Bi 58” manufactured by Mitsui Metals, Inc., particle diameter: 12 μm

Filler:
Filler 1: Nippon Aerosil "AEROSIL R7200"
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) The components shown in Table 1 below were blended in the amounts shown in Table 1 below to obtain a conductive material (anisotropic conductive paste).

(2) Preparation of Connection Structure A 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) as a first connection target member. An epoxy substrate was prepared. One line electrode is an assembly of electrodes in which a plurality of electrodes having an electrode length of 300 μm are arranged at an inter-electrode length of 200 μm in the longitudinal direction of the line electrode. The glass epoxy substrate has a plurality of line electrodes.

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

  The conductive material (anisotropic conductive paste) immediately after fabrication should be 250 ± 20 μm wide, 2200 ± 20 μm long, and 150 ± 30 μm thick along the line electrode on the top surface of the line electrode of the glass epoxy substrate. It apply | coated and the conductive material (anisotropic conductive paste) layer was formed. Next, semiconductor chips were stacked on the top 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 become the melting point of the solder 90 seconds after the start of the temperature rise. Further, after 120 seconds from the start of the temperature rise, the conductive material (anisotropic conductive paste) layer is heated to 170 ° C. to harden the conductive material (anisotropic conductive paste) layer, and the connection structure is obtained. Obtained. During heating, no pressure was applied.

(Evaluation)
(1) Shape Maintaining Property of Conductive Material A glass epoxy substrate and a semiconductor chip used for producing a connection structure were prepared. On the upper surface of the line electrode of the glass epoxy substrate, the obtained conductive material was applied 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 with 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 tweezer or mounter so that the long side portion coincides with the length direction of the conductive material. It stood still on the conditions which load a pressure. The width X1 of the conductive material when left to stand was measured. The above conductive material was pressurized and heated under the pressure condition of 60 Pa after standing and the condition of heating from 40 ° C. to 170 ° C. at a temperature rising rate of 1.08 ° C./sec. The width X2 of the conductive material was measured when the conductive material reached 100.degree. From the obtained measurement results, the ratio of X2 to X1 (X2 / X1) was calculated. The shape retention characteristics of the conductive material were determined based on the following criteria.

[Criteria for determining shape retention characteristics of conductive material]
○: X2 / X1 is 1.18 or less Δ: X2 / X1 exceeds 1.18, 1.25 or less ×: X2 / X1 exceeds 1.25

(2) Insulating Properties Between Adjacent Line Electrodes In the obtained connection structure, it was confirmed by observing between the line electrodes with an optical electron microscope whether or not the melting spread of the conductive material exists between the line electrodes. . The insulation between adjacent line electrodes was determined according to the following criteria.

[Criteria for insulation between adjacent line electrodes]
○: Melting spread of the conductive material does not exist between adjacent line electrodes, and insulation between the adjacent line electrodes is good. ×: Melted spread of the conductive material exists between adjacent line electrodes, adjacent lines Poor insulation between electrodes

(3) Placement accuracy of the solder on the electrode In the obtained connection structure, a portion where the first electrode and the second electrode face each other in the stacking direction of the first electrode, the connection portion, and the second electrode. The ratio Y of the area in which the solder portion in the connection portion is disposed in 100% of the area of the facing portion of the first electrode and the second electrode was evaluated. The placement accuracy of the solder on the electrode was determined according to the following criteria. The ratio Y can be measured by using an image analysis software “Image J” or the like in observation with an optical microscope.

[Criteria for accuracy of placement of solder on electrodes]
○: 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 even in the case of using a flexible printed circuit board, a resin film, a flexible flat cable and a rigid flexible circuit board.

Reference Signs List 1, 1X Connection structure 2 First connection target member 2a First electrode 3 Second connection target member 3a Second electrode 4, 4X Connection portion 4A, 4XA Solder portion 4B, 4XB ... Hardened part 11 ... conductive material 11A ... solder particle 11 B ... thermosetting component 21 ... conductive particle (solder particle)
31 ... conductive particle 32 ... substrate particle 33 ... conductive portion (conductive portion having solder)
33A: second conductive portion 33B: solder portion 41: conductive particle 42: solder portion 51: member 51A: assembly of electrodes 51a: electrode

Claims (10)

A conductive material comprising a thermosetting component and conductive particles,
The conductive material is applied in a line form 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 left to stand under a pressure condition of 60 Pa is X1, and after standing, the pressure condition of 60 Pa and heating conditions from 40 ° C. to 170 ° C. at a heating rate of 1.08 ° C./sec. A conductive material, wherein X2 is not more than 1.25 times X1 when X2 represents the width of the conductive material when the conductive material reaches 100 ° C. by pressing 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, wherein the minimum value of the melt viscosity of the conductive material in a temperature range of 140 ° C. or less is 50 Pa · s or more.   The conductive material according to any one of claims 1 to 3, wherein the thermosetting component comprises a thermosetting compound and a thermosetting agent.   The conductive material according to any one of claims 1 to 4, which contains 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 in a line form. A first connection target member having a first electrode on the surface;
A second connection target member having a second electrode on its surface;
A connection portion connecting the first connection target member and the second connection target member;
The material of the connection portion is the conductive material according to any one of claims 1 to 7,
A connected structure in which the first electrode and the second electrode are electrically connected by the conductive particles. The conductor according to any one of claims 1 to 7 along a line of the first electrode on a surface of a first connection target member having a first electrode arranged in a line on the surface. Applying the material in a line;
A second connection target member having on the surface a second electrode arranged in a line on the surface opposite to the first connection target member side of the conductive material, the first electrode and the first connection target member Placing the two electrodes so as to face each other;
By heating the conductive material, a connection portion connecting the first connection target member and the second connection target member is formed of the conductive material, and the first electrode and the connection member are connected. Electrically connecting the second electrode to the second electrode with the conductive particles. A conductive material including a thermosetting component and conductive particles along a line of the first electrode on a surface of a first connection target member having a first electrode arranged in a line on the surface. Coating step of applying
A second connection target member having on the surface a second electrode arranged in a line on the surface opposite to the first connection target member side of the conductive material, the first electrode and the first connection target member An arrangement step of arranging so that the two electrodes face each other;
By heating the conductive material, a connection portion connecting the first connection target member and the second connection target member is formed of the conductive material, and the first electrode and the connection member are connected. Electrically connecting the second electrode with 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 width of the conductive material at the time when the conductive material reaches 100 ° C. after the start of heating of the conductive material is Xa2 And a method of manufacturing a connection structure in which Xa2 is 1.25 times or less of Xa1.

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