JP6518101B2 - PHOTO-CURABLE CONDUCTIVE MATERIAL, CONNECTION STRUCTURE, AND METHOD FOR MANUFACTURING CONNECTION STRUCTURE - Google Patents

Description

  The present invention relates to a photocurable conductive material containing conductive particles and a photocurable curable component. The present invention also relates to a connection structure using the above-mentioned photocurable 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 resin.

  The anisotropic conductive material is, for example, a connection between a flexible printed substrate and a glass substrate (FOG (Film on Glass)) and a connection between a semiconductor chip and a flexible printed substrate (COF (COF) to obtain various connection structures. It is used for chip on film), connection between semiconductor chip and glass substrate (COG (chip on glass)), connection between flexible printed circuit board and glass epoxy substrate (FOB (film on board)), and the like.

  For example, when electrically connecting an electrode of a semiconductor chip and an electrode of a glass substrate by the anisotropic conductive material, an anisotropic conductive material containing conductive particles is disposed on the glass substrate. Next, the semiconductor chips are stacked, 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.

  As an example of the anisotropic conductive material, Patent Document 1 below discloses a conductive material including a capsule containing a light emitting component in a resin as an adhesive and conductive particles. The capsule containing the light emitting component and the conductive particles are separately blended.

  Patent Document 2 below discloses a light reflective conductive particle including a core particle coated with a metal material and a light reflective layer formed of a light reflective inorganic particle having a refractive index of 1.52 or more. It is disclosed. The light reflecting layer is disposed on the surface of the core particle. The light reflective conductive particles are used for anisotropically conductively connecting a light emitting element to a wiring board.

  Further, Patent Documents 3 and 4 below disclose compositions which are not materials used as a conductive material including conductive particles.

  Patent Document 3 listed below includes (A) component: an epoxy resin, (B) component: an aliphatic compound having an epoxy group and a hydroxyl group, and (C) component: an initiator that generates a cationic species by an active energy ray. And a resin composition having a delayed curing property containing 5 to 45 parts by mass of the component (B) per 100 parts by mass of the component (A).

  Patent Document 4 below discloses an adhesive composition comprising a cationically polymerizable substance (A), an energy ray cationic polymerization initiator (B) and a cationic polymerization retarder (C).

  Patent Document 5 below discloses an adhesive composition comprising (A) an epoxy compound, (B) a photocation generator, and (C) a chain transfer agent having a chain transfer function of cationic polymerization. . The adhesive composition can include conductive particles. Patent Document 5 describes that the adhesive composition may contain a chain ether compound or a cyclic ether compound for the purpose of controlling the curing behavior of the (A) epoxy compound. Examples of linear ether compounds or cyclic ether compounds include polyethylene glycols such as diethylene glycol, triethylene glycol and tetraethylene glycol and derivatives in which the terminal hydroxyl group is functionalized with ether bond or ester bond; ethylene oxide, propylene oxide, cyclohexene oxide, etc. Polymers of monofunctional epoxy compounds; crosslinked products of polyfunctional epoxy compounds; polymers of monofunctional or polyfunctional oxetanes; polymers of monofunctional or polyfunctional tetrahydrofurans; 12-crown-4-ether, 14- Crown-4-ether, 15-crown-5-ether, 18-crown-6-ether, 21-crown-7-ether, 24-crown-8-ether, 30-crown-7-ether, benzo-18- Crown-6- Cyclized polyethylene glycols such as ter, dibenzo-18-crown-6-ether and tribenzo-18-crown-6-ether; cyclized polymers of monofunctional epoxys such as ethylene oxide, propylene oxide and cyclohexene oxide, etc. Is mentioned.

Unexamined-Japanese-Patent No. 2010-254788 JP, 2011-86823, A JP, 2011-38090, A Unexamined-Japanese-Patent No. 11-181391 JP, 2007-100065, A

  In recent years, thinning of various connection target members adhered by a conductive material is in progress. When the connection target member bonded by the conductive material is thin, there is a problem that the connection target member is easily warped by bonding or heat. The occurrence of warpage of the connection target member greatly reduces the reliability of conduction between the electrodes. In order to suppress the warpage, it is desirable to cure the conductive material by heat curing and light curing in order to cure the conductive material by light curing or to lower the heat curing temperature.

  However, if the conductive material is cured by heat curing and light curing in order to cure the conductive material by light curing or to lower the heat curing temperature, light is blocked by the electrodes and conductive particles, and light In some cases, curing of the conductive material portion that was not directly irradiated may be insufficient. Insufficient curing not only causes warping of the connection target member but also causes peeling. In particular, curing tends to be insufficient at portions where light is blocked by the electrodes. This can occur even when using the conductive materials described in Patent Documents 1 and 2.

  On the other hand, it is possible to prevent the light from being blocked by the electrodes by irradiating the conductive material with light from the upper side of the conductive material before laminating the upper connection target member. However, prior to the lamination of the upper connection target member, when the upper connection target member is laminated after the conductive material is irradiated with light from the upper side of the conductive material, the hardening of the conductive material proceeds considerably. The connection target member and the cured product of the conductive material may not be sufficiently connected. This can occur even when using the conductive materials described in Patent Documents 1 and 2.

  In addition, since the composition of patent document 3, 4 is not an electroconductive material containing electroconductive particle, said subject itself does not exist.

  In addition, as described in Patent Document 5, in an adhesive composition using a chain ether compound or a cyclic ether compound, when the pressure at the time of pressure bonding is relatively low at the time of conductive connection, it is between the electrode and the conductive particle. In some cases, the compounding components other than the conductive particles can not be removed sufficiently, and the conduction reliability may be lowered. At the time of conductive connection, a difference in pressure at the time of pressure bonding may occur due to the difference in particle diameter of the conductive particles, and conductive particles to which a pressure is applied may be low.

  The object of the present invention is to suppress warpage of a connection target member when used for connection of a connection target member having an electrode on the surface, and exclude compounding components other than conductive particles between the electrode and conductive particles. Accordingly, it is an object of the present invention to provide a photocurable conductive material which can enhance the conduction reliability between electrodes and can improve the connection reliability between the connection target member and the cured product of the conductive material. Another object of the present invention is to provide a connection structure using the above-mentioned photocurable conductive material and a method of manufacturing the connection structure.

  According to a broad aspect of the present invention, it is a conductive material that is used for connection of a connection target member having an electrode on the surface and that has photo-curing properties, and conductive particles, a photo-curing compound, and a photo cationic polymerization initiator A photocurable conductive material is provided, comprising: a photocuring retarder, wherein the photocuring retarder is attached to the surface of the conductive particles.

  In a specific aspect of the photocurable conductive material according to the present invention, the conductive particles and the photocurable retarder are compounded after the photocurable retarder is attached to the surface of the conductive particles. There is.

  In a specific aspect of the photocurable conductive material according to the present invention, the photocationic polymerization initiator is a photocationic polymerization initiator that generates an acid upon irradiation with light, and the photocuring retarder is a photocationic polymerization. It can capture the acid generated from the initiator.

  The photocurable conductive material according to the present invention connects a first connection target member having a first electrode on the surface and a second connection target member having a second electrode on the surface, and the first And the second electrode are electrically connected to obtain a connection structure, and a photocurable conductive material is disposed on the surface of the first connection target member. After that, the first light irradiation is performed on the photocurable conductive material from the side opposite to the first connection target member side, and then the conductive property is applied between the first electrode and the second electrode. The second connection target member is disposed on the surface opposite to the first connection target member side of the photocurable conductive material subjected to the first light irradiation so that the particles are positioned; When or after the two connection target members are placed, a small amount of the second light irradiation and heat application to the photocurable conductive material One is performed Kutomo, through the steps photocurable conductive material to form a cured product obtained by curing, is preferably used to obtain the connection structure.

  In the photocurable conductive material according to the present invention, (1) a second light irradiation is performed on the photocurable conductive material to form a cured product in which the photocurable conductive material is cured, and then the connection structure is obtained. (2) application of heat to the photocurable conductive material to form a cured product obtained by curing the photocurable conductive material to obtain the connection structure (3) The photocurable conductive material is subjected to the second light irradiation, and heat is applied to the photocurable conductive material to cure the photocurable conductive material. It is also suitably used to obtain the connection structure through the process of forming an object.

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

  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, the first connection target member, and the first connection target member And a connecting portion connecting the second connection target member, wherein the connecting portion is formed by curing the above-described photocurable conductive material, and the first electrode and the second electrode are formed. A connection structure is provided, the electrodes being electrically connected by the conductive particles.

  According to a broad aspect of the present invention, a second connection having a first electrode on the surface and a second electrode on the surface using the above-described photocurable conductive material and having the first electrode on the surface Placing the photocurable conductive material on the surface of the first connection target member using the target member; and the photocurable conductive material disposed on the surface of the first connection target member In the material, the step of performing the first light irradiation from the side opposite to the first connection target member side, and the conductive particles are positioned between the first electrode and the second electrode Disposing the second connection target member on the surface of the photocurable conductive material opposite to the first connection target member side subjected to the first light irradiation; During or after the placement of the connection target member, the photocurable conductive material is subjected to second light irradiation and heat application. And forming a connecting portion connecting the first connection target member and the second connection target member with the cured product of the photocurable conductive material, and A method of manufacturing a connection structure is provided, in which a first electrode and the second electrode are electrically connected by the conductive particles.

  In the method of manufacturing a connection structure according to the present invention, the second light irradiation step includes (1) irradiating the photocurable conductive material with a second light during or after the arrangement of the second connection target member. A second light irradiation step of performing heat treatment, and (2) a heat application step of applying heat to the photocurable conductive material during or after the placement of the second connection target member (3) A second light irradiation is performed on the photocurable conductive material during or after the placement of the second connection target member, and heat is applied to the photocurable conductive material. It is also preferable that it is a light irradiation and heat application process.

  The photocurable conductive material according to the present invention is a photocurable conductive material, and contains conductive particles, a photocurable compound, a photocationic polymerization initiator, and a photocuring retarder, and further contains the above-mentioned light. Since the curing retarder adheres to the surface of the conductive particles, when it is used to connect the connection target member having the electrode on the surface, the warp of the connection target member is suppressed and the electrode and the conductive particles It is possible to improve the reliability of conduction between the electrodes and to improve the reliability of connection between the member to be connected and the cured product of the conductive material by excluding the compounding components other than the conductive particles in between.

FIG. 1 is a cross-sectional view schematically showing a connection structure using a photocurable conductive material according to an embodiment of the present invention. Fig.2 (a)-(d) is sectional drawing for demonstrating an example of the manufacturing method of the connection structure using the photocurable electrically-conductive material which concerns on one Embodiment of this invention. FIG. 3 is a cross-sectional view showing conductive particles used for a photocurable conductive material according to an embodiment of the present invention.

  Hereinafter, the present invention will be described in detail.

  The photocurable conductive material according to the present invention is a conductive material that is used for connection of a connection target member having an electrode on the surface, and that has photocurability. The photocurable conductive material according to the present invention contains conductive particles, a photocurable compound, a photocationic polymerization initiator, and a photocuring retarder. The light curing retarder delays the curing speed of the conductive material after the light irradiation as compared with the case where the light curing retarder is not used. In the photocurable conductive material according to the present invention, the photocurable retarder adheres to the surface of the conductive particles.

  By adopting the above-described configuration in the photocurable conductive material according to the present invention, when used for connection of a connection target member having an electrode on the surface, warpage of the connection target member is suppressed and an electrode and a conductive particle are It is possible to improve the reliability of conduction between the electrodes by eliminating the compounding components excluding the conductive particles between them, and to improve the reliability of connection between the member to be connected and the cured product of the conductive material. In particular, when the photocuring retarder adheres to the surface of the conductive particles, compounding components other than the conductive particles between the electrodes and the conductive particles are excluded at the time of conductive connection, and the inter-electrodes are separated. Conduction reliability can be improved.

  In the present invention, even when the photocurable conductive material is irradiated with light, curing does not proceed rapidly due to the effect of the photocuring retarder, so for example, even before laminating the upper connection target member, Light can be irradiated to the conductive material from the upper side of the conductive material, and even when the light irradiation is performed, a connection structure having excellent connection reliability can be obtained. In addition, when the upper connection target member is laminated, sufficient adhesion can be ensured. Furthermore, when laminating the upper connection target member, the removability of the components excluding the conductive particles between the electrode and the conductive particles is increased. Moreover, in the connection structure obtained, generation | occurrence | production of a void can also be suppressed. In addition, if the conductive material is irradiated with light from the upper side of the conductive material before laminating the upper connection target member, the light can be prevented from being blocked by the electrode, and the conductive material can be uniformly irradiated with light directly. Is possible. By directly irradiating the conductive material with light uniformly, it is possible to prevent the curing rate of the cured product of the conductive material from partially differing. For this reason, the curvature of the connection target member connected by the hardened | cured material of an electrically-conductive material can be suppressed. Even if the connection target member is thin, the warp can be sufficiently suppressed. By suppressing the warpage of the connection target member, the conduction reliability between the electrodes can be enhanced.

  In the present invention, the conductive material can be cured only by light curing, or the conductive material can be cured by heat curing and light curing. When photocuring is performed, the heat curing temperature for sufficiently curing the conductive material can be lowered when the conductive material is heat cured. By lowering the heat curing temperature, the thermal deterioration of the connection target member can be suppressed. Furthermore, by lowering the heat curing temperature, the occurrence of warping of the connection target member due to heat can be effectively suppressed.

  In the present invention, after the conductive material is irradiated with light from the upper side of the conductive material, curing of the conductive material at the time of arrangement of the upper connection target member is suppressed. As a result, even if the upper connection target member is laminated after the conductive material is irradiated with light from the upper side of the conductive material, the upper connection target member and the cured product of the conductive material can be sufficiently connected.

  The photocurable conductive material according to the present invention connects a first connection target member having a first electrode on the surface and a second connection target member having a second electrode on the surface, and the first Is preferably used to electrically connect the second electrode with the second electrode to obtain a connection structure.

  Moreover, regarding the photocurable conductive material according to the present invention, the photocurable conductive material is disposed on the surface of the first connection target member, and then from the side opposite to the first connection target member side The first light irradiation is performed such that the first light irradiation is performed on the photocurable conductive material, and then the conductive particles are positioned between the first electrode and the second electrode. When or after the second connection target member is placed on the surface of the photocurable conductive material opposite to the first connection target member side, a second light is added to the photocurable conductive material. At least one of irradiation and application of heat is performed, and the photocurable conductive material is suitably used to obtain the above-mentioned connection structure through the step of forming a cured cured product. By obtaining the connection structure through such a process, it is possible to obtain a connection structure having high conduction reliability between the electrodes and high connection reliability between the connection target member and the cured product of the conductive material.

  In this case, in the photocurable conductive material according to the present invention, (1) a second light irradiation is performed on the photocurable conductive material to form a cured product in which the photocurable conductive material is cured. And (2) application of heat to the photocurable conductive material to form a cured product obtained by curing the photocurable conductive material. The photocurable conductive material is also preferably used for obtaining a structure, and (3) the photocurable conductive material is subjected to the second light irradiation and the photocurable conductive material is applied with heat. Is suitably used to obtain the connection structure through the step of forming a cured cured product.

  It is preferable that the said photocationic polymerization initiator is a photocationic polymerization initiator which generate | occur | produces an acid by irradiation of light. It is preferable that the said photocuring retarder can capture the acid generated from the photocationic polymerization initiator. It is preferable that a part of the acid is generated from the cationic curing initiator by the first light irradiation, and the acid is generated from the photo cationic polymerization initiator also by the second light irradiation. It is preferable not to generate all the acid from the cationic curing initiator by the first light irradiation. In this case, when an acid is generated from the photocationic polymerization initiator when the conductive material is irradiated with light from the upper side of the conductive material before laminating the connection target member on the upper side, the acid is effective by the photocuring retarder. Are captured. For this reason, even when the conductive material is irradiated with light from the upper side of the conductive material, it is possible to effectively suppress an increase in the degree of curing of the photocurable conductive material before laminating the upper connection target member. In the photocurable conductive material according to the present invention, preferably, the photocuring retarder can not capture part or all of the acid generated from the photocationic polymerization initiator by the second light irradiation. . In this case, the photocurable conductive material can be effectively cured by the second light irradiation. In the present invention, it is preferable that after the first light irradiation, the action of the light curing retarder is expressed, and after the second light irradiation, the action of the light curing delaying agent is not expressed more than after the first light irradiation.

  All acids may be generated by the first light irradiation. In this case, the first connection target member of the photocurable conductive material subjected to the first light irradiation such that the conductive particles are positioned between the first electrode and the second electrode. When or after the second connection target member is placed on the surface opposite to the side, the photocurable conductive material is not subjected to the second light irradiation, and heat is applied to the photocurable conductive material. The curing may be performed only by heat.

  The photocurable conductive material according to the present invention is a conductive material having photocuring and thermosetting properties, and preferably contains a thermosetting compound and a thermosetting agent. In this case, the photocurable conductive material can be effectively cured by applying heat to the photocurable conductive material.

  Moreover, regarding the photocurable conductive material according to the present invention, the photocurable conductive material is disposed on the surface of the first connection target member, and then from the side opposite to the first connection target member side The first light irradiation is performed such that the first light irradiation is performed on the photocurable conductive material, and then the conductive particles are positioned between the first electrode and the second electrode. The second connection target member is disposed on the surface opposite to the first connection target member side of the photocurable conductive material, and after the second connection target member is disposed or after being disposed After the step of forming a cured product in which the photocurable conductive material is cured by applying a second light to the photocurable conductive material and applying heat to the photocurable conductive material; It is suitably used to obtain a structure. By obtaining the connection structure through such a process, it is possible to obtain a connection structure in which the conduction reliability between the electrodes is further enhanced, and the connection reliability between the connection target member and the cured product of the conductive material is further enhanced. Can.

  The photocurable conductive material is preferably a circuit connection material. The photocurable conductive material is preferably an anisotropic conductive material. The anisotropic conductive material includes a conductive material for conducting between the upper and lower electrodes.

  The photocurable conductive material can be used as a conductive paste and a conductive film. When the photocurable conductive material is a conductive film, a film containing no conductive particles may be laminated on the conductive film containing the conductive particles.

  The photocurable conductive material is preferably a conductive paste from the viewpoint of suppressing generation of voids in the connection portion of the connection structure and further enhancing the conduction reliability. It is preferable that the said photocurable electrically-conductive material is an electrically conductive paste, and is coated on the upper surface of a connection object member in a paste-like state.

  Next, with reference to FIG. 1, a connection structure using a photocurable conductive material according to an embodiment of the present invention will be specifically described.

  FIG. 1 is a cross-sectional view schematically showing a connection structure using a photocurable conductive material according to an embodiment of the present invention. The connection structure 1 shown in FIG. 1 includes a first connection target member 2 having a first electrode 2a on the surface, a second connection target member 3 having a second electrode 3a on the surface, and a first connection. The connection part 4 which has connected the object member 2 and the 2nd connection object member 3 is provided. The connection portion 4 includes the cured product 11 of the light curing component.

  The first electrode 2a and the second electrode 3a are electrically connected by conductive particles 21 (conductive particles 21 in a conductive particle composite 22 shown in FIG. 3 described later). The connection portion 4 includes the conductive particle 21, the photocurable compound, the photocationic polymerization initiator, and the light curing retarder (consumed at the connection portion 4 and detached from the surface of the conductive particle 21). And photocuring conductive material containing light, and curing the photocurable conductive material.

  Specifically, the connection structure 1 shown in FIG. 1 can be obtained as follows, for example, via the states shown in FIGS. 2 (a) to 2 (d). Here, as the photocurable conductive material, a photocurable compound, a photocationic polymerization initiator, and a photocuring retarder 33 (see FIG. 3), and a photocurable and thermosetting photocurable resin. Conductive materials (photo-curable and thermosetting conductive materials) are used. In the following description, the photocurable compound, the photocationic polymerization initiator, and the photocuring retarder 33 may be described as a photocurable component. In addition, you may use the photocurable electrically-conductive material which does not have thermosetting property and has only photocurable property. The photocurable compound not only acts as a photocurable compound, but may act as a thermosetting compound or may be a photo and thermosetting compound.

  As shown to Fig.2 (a), the 1st connection object member 2 which has the 1st electrode 2a on the surface (upper surface) is prepared. In addition, a photocurable conductive material including a plurality of conductive particles 21 and a photocurable component including the photocurable retarder 33 is prepared. As shown in FIG. 3, the light curing retarder 33 adheres to the surface of the conductive particles 21. In the present embodiment, the conductive particle complex 22 in which the light curing retarder 33 adheres to the surface of the conductive particles 21 is used. Next, the photocurable conductive material layer 4A is disposed on the surface of the first connection target member 2 on the first electrode 2a side using the above-described photocurable conductive material. At this time, it is preferable that one or more conductive particles 21 be disposed on the first electrode 2a. Here, since the conductive paste is used as the photocurable conductive material, the placement of the conductive paste is performed by applying the conductive paste. The photocurable conductive material layer 4A is a conductive paste layer.

  Next, before disposing the upper second connection target member 3, light is irradiated to the photocurable conductive material layer 4A from the upper side of the photocurable conductive material layer 4A (first light irradiation step). That is, before the second connection target member 3 is disposed, the first light irradiation is applied to the photocurable conductive material layer 4A from the side opposite to the first connection target member 2 side of the photocurable conductive material layer 4A. Do. In the present embodiment, since the first light irradiation is performed before the arrangement of the second connection target member 3, the light is not blocked by the second electrode 3 a of the second connection target member 3. For this reason, light can be directly and relatively uniformly delivered to the entire region of the photocurable conductive material layer 4A. On the other hand, when the first light irradiation is performed after the second connection target member 3 is disposed, the light is blocked by the second electrode 3a, and the light is not directly irradiated to the photocurable conductive material layer 4A. Exists. If the first light irradiation is performed before the placement of the second connection target member 3, although there is a region of the photocurable conductive material layer 4A in which light is blocked by the conductive particles 21, per one of the regions is present. The size is smaller than the size of the region of the photocurable conductive material layer 4A in which light is blocked by the second electrode 3a. The effect of the region of the photocurable conductive material layer 4A in which light is blocked by the conductive particles 21 is smaller than the effect of the region of the photocurable conductive material layer 4A in which light is blocked by the second electrode 3a.

  As shown in FIGS. 2A and 2B, the photocurable conductive material layer 4A becomes a photocurable conductive material layer 4B subjected to the first light irradiation by the first light irradiation. After the first light irradiation, the curing of the photocurable conductive material layer 4B does not proceed rapidly due to the influence of the photocuring retarder, and the curing speed of the photocurable conductive material layer 4B is slow. As a result, in the photocurable conductive material layer 4B, curing is suppressed.

  Next, as shown in FIG. 2 (c), on the surface opposite to the first connection target member 2 side of the photocurable conductive material layer 4B subjected to the first light irradiation, a second The second connection target member 3 having the electrode 3a on the surface is disposed from the second electrode 3a side. That is, the light curable conductive material layer 4B is disposed between the first connection target member 2 and the second connection target member 3. Further, the second connection target member 3 is disposed such that the first electrode 2a and the second electrode 3a face each other. At this time, the photocurable conductive material layer 4B is disposed so that the conductive particles 21 are positioned between the first electrode 2a and the second electrode 3a.

  At the time of arrangement of the second connection target member 3 or after the arrangement, the second light irradiation is performed on the photocurable conductive material layer 4B subjected to the first light irradiation (second light irradiation process). Further, heat is applied to the photocurable conductive material layer 4B during or after the second connection target member 3 is disposed (a first heat application step). Heat is preferably applied by the thermocompression bonding head 51. It is preferable that heat be applied to the photocurable conductive material layer 4B by thermocompression bonding the first connection target member 2 and the second connection target member 3. When heat is applied, the second light irradiation may not be performed. As a result of the progress of the curing of the photocurable conductive material layer 4B by the second light irradiation, preferably by the second light irradiation and the application of the first heat, or by the application of the first heat, FIG. As shown in d), the photocurable conductive material layer 4C in which the curing has progressed is formed. At this point, connection 4 may be formed.

  At the time of arrangement of the second connection target member or after the arrangement, the step of performing at least one of the second light irradiation and the application of heat to the photocurable conductive material may be performed. The second light irradiation step is (1) the second light irradiation step of irradiating the photocurable conductive material with the second light during or after the arrangement of the second connection target member Preferably, (2) heat is applied to the photocurable conductive material during or after the placement of the second connection target member, and (3) the second connection target It is also a second light irradiation and heat application process in which the second light irradiation is applied to the photocurable conductive material and the heat application is applied to the photocurable conductive material during or after the arrangement of the member. preferable.

  Preferably, the second heat is applied to the photocurable conductive material layer 4C after the application of the first heat or after the application of the second light and the first heat. Forming the connection portion 4 (second heat application step), and more preferably, after the second light irradiation and the first heat application, the second heat-curable conductive material layer 4C Forming the connection portion 4 (second heat application step).

  As a result, the connection structure 1 shown in FIG. 1 is obtained.

  The light source used at the time of the first light irradiation and the second light irradiation is not particularly limited. Examples of the light source include a light source having a sufficient light emission distribution at a wavelength of 420 nm or less, a light source having strong light emission at a specific wavelength of 420 nm or less, and the like. Specific examples of light sources having a sufficient light emission distribution at a wavelength of 420 nm or less include, for example, low pressure mercury lamps, medium pressure mercury lamps, high pressure mercury lamps, ultra high pressure mercury lamps, chemical lamps, black light lamps, microwave excited mercury lamps, metal halide lamps and the like. It can be mentioned. Moreover, an LED lamp etc. are mentioned as a specific example of a light source which has strong light emission to the specific wavelength of wavelength 420 nm or less. Among them, LED lamps are preferred. When the LED lamp is used, the heat generation of the object to be irradiated itself becomes very small, and the excessive heat deterioration of the photocurable conductive material due to the heat generation can be prevented.

Light irradiation amount in the first light irradiation is preferably 50 to 500 mJ / cm ^2, more preferably about 100 mJ / cm ² or more, more preferably 150 mJ / cm ² or more, more preferably 400 mJ / cm ² or less, More preferably, it is 300 mJ / cm ² or less.

In order to cure the photocurable conductive material layer by the second light irradiation, a light irradiation amount for curing the photocurable conductive material layer appropriately is preferably about 300 to 1000 mJ / cm ² , more preferably 400 mJ / cm ² or more, more preferably 500 mJ / cm ² or more, more preferably 900 mJ / cm ² or less, more preferably 800 mJ / cm ² or less.

  From the viewpoint of suppressing the progress of curing by the first light irradiation and effectively advancing the curing by the second light irradiation, the light irradiation intensity in the first light irradiation is the light irradiation intensity in the second light irradiation. It is preferable that it is smaller than. The light irradiation intensity in the first light irradiation is preferably 1/2 or less of the light irradiation intensity in the second light irradiation, and more preferably 1/3 or less.

The photocurable conductive material 60 seconds after irradiation with the viscosity η1 of the photocurable conductive material before the first light irradiation and the ultraviolet light having a wavelength of 365 nm so that the light irradiation amount is 150 mJ / cm ² The ratio (η2 // 1) of the viscosity η2 to the viscosity η1 is preferably 1.5 or less, more preferably 1.3 or less. The ratio (η 2 / η 1) is generally 0.5 or more, preferably 0.8 or more, more preferably 0.9 or more, and still more preferably 1 or more.

  The second light irradiation may be performed at the time of arrangement of the second connection target member or after the arrangement, may be performed at the time of arrangement, or may be performed after the arrangement. However, the second light irradiation is more preferably performed after the placement. In addition, the second light irradiation and the first heat application may be performed simultaneously or separately, or the first heat application may be performed after the second light irradiation. The second light irradiation may be performed after the application of the first heat. It is preferable that the second light irradiation and the application of the first heat be performed simultaneously.

  When the photocurable conductive material is cured by applying heat, the heating temperature for appropriately curing the photocurable conductive material layer is preferably 80 ° C. or more, more preferably 100 ° C. or more, preferably Is 150.degree. C. or less, more preferably 130.degree. C. or less.

  When the application of the first heat and the application of the second heat are performed, the heating temperature in the application of the first heat is preferably 80 ° C. or more, more preferably 100 ° C. or more, preferably 150 C. or less, more preferably 130 ° C. or less. The heating temperature in the application of the second heat is preferably 80 ° C. or more, more preferably 100 ° C. or more, preferably 150 ° C. or less, more preferably 130 ° C. or less.

  The application of the first heat is preferably performed at the time of or after arrangement of the second connection target member, and may be performed at the time of arrangement or may be performed after the arrangement. However, the application of the first heat is more preferably performed at the time of arrangement.

  In the method of manufacturing the connection structure 1 described above, even if the photocurable conductive material layer 4A is subjected to the first light irradiation, the curing does not rapidly proceed due to the adoption of the photocuring retarder, for example, Before the arrangement of the second connection target member 3, light can be emitted to the photocurable conductive material layer 4 </ b> A from the opposite side of the photocurable conductive material layer 4 </ b> A to the first connection target member 2 side. If the first light irradiation is performed on the photocurable conductive material layer 4A from the opposite side of the photocurable conductive material layer 4A to the first connection target member 2 before the second connection target member 3 is disposed, It is possible to prevent the light from being blocked by the second electrode 3a, and it is possible to irradiate the light directly to the photocurable conductive material layer 4A uniformly. By directly irradiating light to the photocurable conductive material layer 4A uniformly, it is possible to prevent the curing rate of the cured product (connecting portion 4) of the photocurable conductive material from being partially different. For this reason, the curvature of the 1st, 2nd connection object members 2 and 3 connected by the hardened | cured material (connection part) of a photocurable electrically-conductive material can be suppressed. Even if the first and second connection target members 2 and 3 are thin, the warp can be sufficiently suppressed. Furthermore, before the second connection target member 3 is disposed, the first light irradiation is performed on the photocurable conductive material layer 4A from the side opposite to the first connection target member 2 side of the photocurable conductive material layer 4A. Thereafter, excessive curing of the photocurable conductive material layer 4B at the time of arrangement of the second connection target member 3 is suppressed. As a result, after the first light irradiation is applied to the photocurable conductive material layer 4A from the opposite side to the first connection target member 2 side of the photocurable conductive material layer 4A, the second connection target member 3 is obtained. Even when the second connection target member 3 is disposed, the second connection target member 3 and the cured product (connection portion 4) of the photocurable conductive material can be sufficiently connected. Furthermore, since the photo-curing retarder particularly adheres to the surface of the conductive particles, the conductive components between the electrodes and the conductive particles are excluded at the time of conductive connection, and the conduction reliability between the electrodes is eliminated. Can be enhanced.

  Hereinafter, other details of the conductive particles, the photocurable conductive material, and the connection structure will be described.

(Conductive particles)
In FIG. 3, the electroconductive particle 21 used for the photocurable electrically-conductive material which concerns on one Embodiment of this invention, and the electroconductive particle composite 22 provided with this electroconductive particle 21 are shown with sectional drawing.

  The conductive particle complex 22 shown in FIG. 3 has the conductive particles 21 and the light curing retarder 33 attached to the surface of the conductive particles 21. The light curing retarder 33 adheres to the surface of the conductive particles 21. In the photocurable conductive material, the conductive particle composite 22 in which the photocuring retarder 33 adheres to the surface of the conductive particles 21 is used. By using this conductive particle composite 22, it is possible to eliminate the blending components other than the conductive particles between the electrode and the conductive particles, and to improve the conduction reliability between the electrodes. Furthermore, the use of the conductive particle composite 22 makes it difficult for the photocuring retarder to lower the adhesiveness of the photocurable conductive material, and the connection reliability is further enhanced in the connection structure.

  The conductive particles 21 electrically connect the first and second electrodes 2 a and 3 a of the first and second connection target members 2 and 3. The conductive particles 21 include base particles 31 and conductive portions 32 disposed on the surfaces of the base particles 31. The conductive portion 32 is a conductive layer. An insulating material may be disposed on the conductive surface of the conductive particles. An insulating material may be disposed on the outer surface of the conductive portion. Note that the insulating substance is removed from between the conductive layer and the electrode at the time of connection of the connection target member. The conductive particles may have protrusions on the conductive surface. The conductive particle may have a protrusion on the outer surface of the conductive portion.

  Moreover, although the conductive particle 21 has the base particle 31, the conductive particle may be entirely formed of a conductive material. The whole of the conductive particles may be a conductive portion. Moreover, although the electroconductive particle 21 has the electroconductive part 32 (electroconductive layer) of a single | mono layer, the electroconductive particle may have a multilayer electroconductive layer.

  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 is preferably a resin particle formed of a resin. When connecting the electrodes, after the conductive particles are disposed between the electrodes, generally, the conductive particles are compressed. When the substrate particles are resin particles, the conductive particles are easily deformed by compression, and the contact area between the conductive particles and the electrode becomes large. For this reason, the conduction reliability between the electrodes is enhanced.

  Various organic substances 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; and polyalkylene terephthalates and polysulfones Polycarbonate, polyamide, phenol formaldehyde resin, melamine formaldehyde resin, benzoguanamine formaldehyde resin, urea formaldehyde resin, phenol resin, melamine resin, benzoguanamine resin, urea resin, epoxy resin, unsaturated polyester resin, saturated polyester resin, polysulfone, polyphenylene oxide, Polyacetal, polyimide, polyamide imide, polyether ether Tons, polyethersulfone, and polymers such as obtained by a variety of polymerizable monomer having an ethylenically unsaturated group is polymerized with one or more thereof. In addition, by polymerizing one or two or more of various polymerizable monomers having an ethylenically unsaturated group, design and synthesis of resin particles having physical properties upon compression suitable for a photocurable conductive material It is possible. In addition, since the hardness of the substrate particles can be easily controlled in a suitable range, the material of the resin particles is a polymer obtained by polymerizing one or two or more polymerizable monomers having a plurality of ethylenically unsaturated groups. Is preferred.

  When the resin particles are obtained by polymerizing a monomer having an ethylenically unsaturated group, as the monomer having an ethylenically unsaturated group, a monomer having a crosslinking property with a non-crosslinkable monomer is used. And a mer.

  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) acrylates such as meta) acrylate and isobornyl (meth) acrylate; oxygen such as 2-hydroxyethyl (meth) acrylate, glycerol (meth) acrylate, polyoxyethylene (meth) acrylate and glycidyl (meth) acrylate (Meth) acrylates; nitrile-containing monomers such as (meth) acrylonitrile; vinyl ethers such as methyl vinyl ether, ethyl vinyl ether and propyl vinyl ether; vinyl acids such as vinyl acetate, vinyl butyrate, vinyl laurate and vinyl stearate Esters; unsaturated hydrocarbons such as ethylene, propylene, isoprene and butadiene; trifluoromethyl (meth) acrylates, pentafluoroethyl (meth) acrylates, halogen-containing monomers such as vinyl chloride, vinyl fluoride and chlorostyrene, etc. 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) acrylates such as acrylate, (poly) tetramethylene glycol di (meth) acrylate, 1,4-butanediol di (meth) acrylate; triallyl (iso) cyanurets And silane-containing monomers such as triallyl trimellitate, divinylbenzene, diallyl phthalate, diallyl acrylamide, diallyl ether, .gamma .- (meth) acryloxypropyltrimethoxysilane, trimethoxysilylstyrene, vinyltrimethoxysilane, etc. Be

  The said resin particle is 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 and carbon black. 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.

  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. However, it is preferable that a substrate particle is not a metal particle.

  The average particle diameter of the substrate particles is preferably 0.1 μm or more, more preferably 0.5 μm or more, still more preferably 1 μm or more, still more preferably 1.5 μm or more, particularly preferably 2 μm or more, preferably 1000 μm or less More preferably, it is 500 μm or less, still more preferably 300 μm or less, still more preferably 100 μm or less, still more preferably 50 μm or less, still more preferably 30 μm or less, particularly preferably 5 μm or less, most preferably 3 μm or less. When the average particle diameter of the substrate particles is at least the above lower limit, the contact area between the conductive particles and the electrodes is increased, so that the conduction reliability between the electrodes is further enhanced, and the connection is made via the conductive particles. The connection resistance between the electrodes becomes even lower. Furthermore, when the conductive portion is formed on the surface of the substrate particle by electroless plating, it is difficult to aggregate, and the aggregated conductive particles are hardly formed. If the average particle diameter of the substrate particles is less than or equal to the above upper limit, the conductive particles are easily compressed, the connection resistance between the electrodes is further reduced, and the distance between the electrodes is narrowed.

  The average particle diameter of the substrate particles is particularly preferably 0.1 μm or more and 5 μm or less. If the average particle diameter of the base particle is in the range of 0.1 to 5 μm, the distance between the electrodes becomes small, and the small conductive particles can be obtained even if the thickness of the conductive portion is increased. From the viewpoint of obtaining smaller conductive particles even if the distance between the electrodes is further decreased or the thickness of the conductive portion is increased, the average particle diameter of the base particles is preferably 0. It is 5 μm or more, more preferably 2 μm or more, and preferably 3 μm or less. From the viewpoint of further enhancing the connection reliability and the conduction reliability, the average particle diameter of the base material particles is preferably 2.6 μm or more.

  The average particle size of the substrate particles indicates a number average particle size. The average particle size can be measured, for example, using Coulter Counter (manufactured by Beckman Coulter, Inc.).

  The thickness of the conductive portion is preferably 5 nm or more, more preferably 10 nm or more, still more preferably 20 nm or more, particularly preferably 50 nm or more, preferably 1000 nm or less, more preferably 800 nm or less, still more preferably 500 nm or less, particularly preferably It is 400 nm or less, most preferably 300 nm or less. The thickness of the above-mentioned conductive part is the thickness of the whole of a plurality of conductive parts, when there are a plurality of conductive parts. The electroconductivity of the said electroconductive particle becomes still more favorable for the thickness of the said electroconductive part to be more than the said minimum. When the thickness of the conductive portion is equal to or less than the upper limit, the difference in thermal expansion coefficient between the base particle and the conductive portion becomes small, and the conductive portion is hardly peeled from the base particle.

  As a method of forming the said conductive part on the surface of the said substrate particle, the method of forming the said conductive part by electroless plating, the method of forming the said conductive part by electroplating, etc. are mentioned.

  The conductive portion preferably contains a metal. The metal which is a material of the said 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, tungsten, molybdenum and cadmium, and alloys of these, etc. Can be mentioned. 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 average particle diameter of the conductive particles is preferably 1.5 μm or more, more preferably 2.5 μm or more, preferably 10 μm or less, more preferably 5 μm or less from the viewpoint of further enhancing the conduction reliability between the electrodes. is there. From the viewpoint of further enhancing the connection reliability and the conduction reliability, the average particle diameter of the conductive particles is preferably 2.8 μm or more.

  The average particle size of the conductive particles indicates a number average particle size. The average particle size can be determined using a particle size distribution measuring device or the like.

  The conductive particles preferably have a plurality of protrusions on the conductive surface. In addition, a protrusion can be easily formed in the outer surface of the said electroconductive part by the core substance being embedded in the said electroconductive part. The projections increase both the connection reliability and the conduction reliability. An oxide film is often formed on the surface of the electrode connected by the conductive particles. In the case where conductive particles having protrusions are used, the conductive film is disposed between the electrodes and pressure-bonded to effectively eliminate the oxide film by the protrusions. For this reason, the electrode and the conductive particles come into contact more reliably, and the connection resistance between the electrodes is further reduced. Further, the protrusions effectively eliminate the compounding component (binder resin) excluding the conductive particles between the conductive particles and the electrode. For this reason, the conduction reliability between the electrodes is enhanced.

  A conventionally known method can be employed as a method of forming a protrusion on the surface of the conductive particle. After the core substance is attached to the surface of the base particle, the conductive part is formed by electroless plating, and after the conductive part is formed by electroless plating on the surface of the base particle, the core substance is adhered, The method etc. which form a conductive part by electroless plating are mentioned. As another method of forming the above-mentioned protrusion, after forming the first conductive portion on the surface of the base particle, the core material is disposed on the first conductive portion, and then the second conductive portion is formed. Of forming a conductive portion on the surface of a substrate particle, a method of adding a core substance in the middle of forming a conductive portion on the surface of a substrate particle, and a method of depositing a core substance in the middle of forming a conductive portion on the surface of a substrate particle Etc.

  Examples of the material of the core substance include conductive substances and non-conductive substances. Examples of the conductive substance include metals, metal oxides, conductive nonmetals such as graphite, and conductive polymers. Examples of the conductive polymer include polyacetylene and the like. Examples of the nonconductive material include silica, alumina and zirconia. Among them, metals are preferable because the conductivity can be enhanced and the connection resistance can be effectively lowered. The core material is preferably metal particles.

  The conductive particle preferably comprises an insulating material disposed on the surface of the conductive particle. In this case, when the conductive particles are used for connection between electrodes, a short circuit between adjacent electrodes can be prevented. Specifically, when a plurality of the conductive particles are in contact with each other, an insulating material is present between the plurality of conductive particles, so that a short circuit between adjacent electrodes in the lateral direction instead of between the upper and lower electrodes can be prevented. In addition, at the time of the connection between electrodes, the insulating substance between a conductive layer and an electrode can be easily removed by pressurizing the said electroconductive particle with two electrodes. The refractive index of the material of the insulating material may be less than 1.6.

  The insulating material is preferably insulating particles, because the insulating material can be more easily removed at the time of pressure bonding between the electrodes.

  The material of the insulating material is preferably an organic material or an organic-inorganic hybrid material. That is, the insulating substance (such as insulating particles) is preferably formed of an organic substance or an organic-inorganic hybrid substance.

  The content of the conductive particles is preferably 0.01% by weight or more, more preferably 0.1% by weight or more, still more preferably 1% by weight or more, particularly preferably 100% by weight of the photocurable conductive material. % By weight, preferably 80% by weight or less, more preferably 40% by weight or less, still more preferably 30% by weight or less, particularly preferably 20% by weight or less, most preferably 10% 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, conduction reliability between the electrodes is further enhanced.

(Photo-curable component)
The photocurable conductive material is photocurable. The photocurable conductive material contains a curable compound, a photocationic polymerization initiator, and a photocuring retarder. The said curable compound contains a photocurable compound (compound curable by irradiation of light). The photocurable conductive material preferably has photocurable and thermosetting properties. The photocurable conductive material is a photocurable compound (a compound curable by irradiation of light), a photocationic polymerization initiator, a photocuring retarder, and a thermosetting compound (compound curable by application of heat) It is also preferable to include and the thermosetting agent. The photocurable compound (compound curable by irradiation of light) may be a light and thermosetting compound (compound curable by irradiation of light and application of heat). The photo cationic polymerization initiator may be a photo and thermal cationic polymerization initiator.

  The photocurable conductive material preferably has photocurable and thermosetting properties. In this case, for example, the application of heat can cure the photocurable conductive material more satisfactorily, and the degree of cure of the cured product of the photocurable conductive material can be effectively increased.

  The photocurable conductive material according to the present invention is preferably used after being cured by applying heat or applying second light and heat after the first light irradiation, It is more preferable that the second light irradiation and the heat application be performed after the light irradiation, and the resin be used after being cured. By curing the photocurable conductive material as described above, the effects of the present invention can be obtained more effectively.

  The method of dispersing the conductive particles in the photocurable component can be a conventionally known dispersion method and is not particularly limited.

  The content of the components excluding the conductive particles is preferably 10% by weight or more, more preferably 30% by weight or more, still more preferably 50% by weight or more, and preferably 90.98% by weight in 100% by weight of the photocurable conductive material. It is at most weight percent. The said electroconductive particle is efficiently arrange | positioned between electrodes as content of the component except the said electroconductive particle is more than the said minimum and below the said upper limit, and the conduction reliability between electrodes becomes still higher.

Photocurable compound:
The photocurable conductive material contains a photocurable compound so as to be cured by light irradiation.

  It does not specifically limit as said photocurable compound, The photocurable compound which has a (meth) acryloyl group, the photocurable compound which has cyclic ether group, etc. are mentioned.

  The photocurable compound is preferably a photocurable compound having a (meth) acryloyl group. The use of a photocurable compound having a (meth) acryloyl group further enhances the conduction reliability between the electrodes. From the viewpoint of effectively enhancing the conduction reliability between the electrodes, the photocurable compound preferably has one or two (meth) acryloyl groups.

  The photocurable compound having a (meth) acryloyl group includes a photocurable compound having no epoxy group and no thiirane group and having a (meth) acryloyl group, and an epoxy group or a thiirane group, and The photocurable compound which has a meth) acryloyl group is mentioned.

  An ester compound obtained by reacting (meth) acrylic acid and a compound having a hydroxyl group as the photocurable compound having a (meth) acryloyl group, an epoxy obtained by reacting a (meth) acrylic acid and an epoxy compound (Meth) acrylate or urethane (meth) acrylate obtained by reacting an isocyanate with a (meth) acrylic acid derivative having a hydroxyl group is preferably used. The above "(meth) acryloyl group" indicates an acryloyl group and a methacryloyl group. The above "(meth) acrylic" indicates acrylic and methacrylic. The above "(meth) acrylate" indicates acrylate and methacrylate.

  The ester compound obtained by reacting the (meth) acrylic acid with the compound having a hydroxyl group is not particularly limited. As the ester compound, any of monofunctional ester compounds, bifunctional ester compounds and trifunctional or higher ester compounds can be used.

  The photocurable compound having an epoxy group or thiirane group and having a (meth) acryloyl group is a part of epoxy group or a part of thiirane of a compound having two or more epoxy groups or two or more thiirane groups. It is preferable that it is a photocurable compound obtained by converting a group into a (meth) acryloyl group. Such photocurable compounds are partial (meth) acrylated epoxy compounds or partial (meth) acrylated episulfide compounds.

  The photocurable compound is preferably a reaction product of a compound having two or more epoxy groups or two or more thiirane groups with (meth) acrylic acid. This reactant can be obtained by reacting a compound having two or more epoxy groups or two or more thiirane groups with (meth) acrylic acid in the presence of a catalyst according to a conventional method.

  As said partial (meth) acrylated epoxy compound, bisphenol type epoxy (meth) acrylate, cresol novolak type epoxy (meth) acrylate, carboxylic acid anhydride modified epoxy (meth) acrylate, phenol novolac type epoxy (meth) acrylate, etc. Can be mentioned.

  As said photocurable compound, it is using the modified phenoxy resin which converted the epoxy group of epoxy group, or some epoxy groups of phenoxy resin which has 2 or more of thiirane groups into a (meth) acryloyl group. It is also good. That is, a modified phenoxy resin having an epoxy group or thiirane group and a (meth) acryloyl group may be used.

  The photocurable compound may be a crosslinkable compound or a noncrosslinkable compound.

  Specific examples of the crosslinkable compound include, for example, 1,4-butanediol di (meth) acrylate, 1,6-hexanediol di (meth) acrylate, 1,9-nonanediol di (meth) acrylate, (poly ) Ethylene glycol di (meth) acrylate, (poly) propylene glycol di (meth) acrylate, neopentyl glycol di (meth) acrylate, pentaerythritol di (meth) acrylate, glycerin methacrylate acrylate, pentaerythritol tri (meth) acrylate, tri Methylol propane trimethacrylate, allyl (meth) acrylate, vinyl (meth) acrylate, divinylbenzene, polyester (meth) acrylate, urethane (meth) acrylate and the like can be mentioned.

  Specific examples of the non-crosslinkable compound include ethyl (meth) acrylate, n-propyl (meth) acrylate, isopropyl (meth) acrylate, n-butyl (meth) acrylate, isobutyl (meth) acrylate, t-butyl (meth) ) Acrylate, pentyl (meth) acrylate, hexyl (meth) acrylate, heptyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, n-octyl (meth) acrylate, isooctyl (meth) acrylate, nonyl (meth) acrylate, decyl Examples include (meth) acrylate, undecyl (meth) acrylate, dodecyl (meth) acrylate, tridecyl (meth) acrylate and tetradecyl (meth) acrylate.

  The content of the photocurable compound is preferably 60% by weight or more, more preferably 80% by weight or more, and preferably 90% by weight or less in 100% by weight of the photocurable conductive material. When the content of the photocurable compound is not less than the lower limit and not more than the upper limit, the photocurable conductive material is appropriately photocured.

Photo cationic polymerization initiator:
The said photocationic polymerization initiator generate | occur | produces a cation by irradiation of light. An iodonium salt and a sulfonium salt are suitably used as said photocationic polymerization initiator. As a commercial item of the said photocationic polymerization initiator, SunAid SI-45L, SanAid SI-60L, SanAid SI-80L, SanAid SI-100L, SanAid SI-110L, SanAid SI-150L (all manufactured by Sanshin Chemical Co., Ltd.) Adeka Optomer SP-150, Adeka Optomer SP-170, Adeka Optomer SP-171 (above, made by ADEKA Corporation), UVE-1014 (made by General Electronics Corporation), CD-1012 (made by Sartomer Corporation), etc. It can be mentioned.

Preferred anionic moieties of the cationic photopolymerization initiator include PF ₆ , BF ₄ , and B (C ₆ F ₅ ) ₄ .

  Moreover, as other specific examples of the said photocationic polymerization initiator, 2-butenyl dimethyl sulfonium tetrakis (pentafluorophenyl) borate, 2-butenyl dimethyl sulfonium tetrafluoroborate, 2- butenyl dimethyl sulfer Phonium hexafluorophosphate, 2-butenyl tetramethylene sulfonium tetrakis (pentafluorophenyl) borate, 2-butenyl tetramethylene sulfonium tetrafluoroborate, 2-butenyl tetramethylene sulfonium hexafluorophosphate, 3 -Methyl-2-butenyldimethylsulfonium tetrakis (pentafluorophenyl) borate, 3-methyl-2-butenyldimethylsulfonium tetrafluoroborate, 3-methyl-2-butenyldimethyls Phonium hexafluorophosphate, 3-methyl-2-butenyl tetramethylene sulfonium tetrakis (pentafluorophenyl) borate, 3-methyl-2-butenyl tetramethylene sulfonium tetrafluoroborate, 3-methyl-2- Butenyl tetramethylene sulfonium hexafluorophosphate, 4-hydroxyphenylcinnamyl methyl sulfonium tetrakis (pentafluorophenyl) borate, 4-hydroxyphenyl cinnamyl methyl sulfonium tetrafluoroborate, 4-hydroxyphenyl cinnamyl methyl Sulfonium hexafluorophosphate, α-naphthylmethyl tetramethylene sulfonium tetrakis (pentafluorophenyl) borate, α-naphthylmethyl tetramethyl Snulphonium tetrafluoroborate, α-naphthylmethyl tetramethylene sulfonium hexafluorophosphate, cinnamyl dimethyl sulfonium tetrakis (pentafluorophenyl) borate, cinnamyl dimethyl sulfonium tetrafluoroborate, cinnamyl dimethyl sulfonium Hexafluorophosphate, cinnamyl tetramethylene sulfonium tetrakis (pentafluorophenyl) borate, cinnamyl tetramethylene sulfonium tetrafluoroborate, cinnamyl tetramethylene sulfonium hexafluorophosphate, biphenyl methyl dimethyl sulfonium tetrakis Fluorophenyl) borate, biphenyl methyl dimethyl sulfonium tetrafluoroborate, Biphenylmethyldimethyl sulfonium hexafluorophosphate, biphenyl methyl tetramethylene sulfonium tetrakis (pentafluorophenyl) borate, biphenyl methyl tetramethylene sulfonium tetrafluoroborate, biphenyl methyl tetramethylene sulfonium hexafluorophosphate, phenyl methyl dimethyl Sulfonium tetrakis (pentafluorophenyl) borate, phenylmethyl dimethyl sulfonium tetrafluoroborate, phenyl methyl dimethyl sulfonium hexafluorophosphate, phenyl methyl tetramethylene sulfonium tetrakis (pentafluorophenyl) borate, phenyl methyl tetramethylene Sulfonium tetrafluoroborate, phenyl group Tetramethylene sulfonium hexafluorophosphate, fluorenylmethyl dimethyl sulfonium tetrakis (pentafluorophenyl) borate, fluorenyl methyl dimethyl sulfonium tetrafluoroborate, fluorenyl methyl dimethyl sulfonium hexafluorophosphate, Examples thereof include fluorenylmethyl tetramethylene sulfonium tetrakis (pentafluorophenyl) borate, fluorenyl methyl tetramethylene sulfonium tetrafluoroborate, and fluorenyl methyl tetramethylene sulfonium hexafluorophosphate.

  It is preferable that the said photocationic polymerization initiator discharge | releases an inorganic acid ion by irradiation of light, or discharge | releases the organic acid ion containing a boron atom by irradiation of light. It is preferable that the said photocationic polymerization initiator is a component which discharge | releases an inorganic acid ion by irradiation of light, and it is also preferable that it is a component which discharge | releases the organic acid ion containing a boron atom by irradiation of light.

It is preferable that the photocationic polymerization initiator which releases inorganic acid ion by irradiation of light is a compound which has SbF ^6- or PF ^6- as an anion part. The photo cationic polymerization initiator is preferably a compound having SbF ^6- as an anion moiety, and is also preferably a compound having PF ^6- as an anion moiety.

Anionic portion of the cationic photopolymerization initiator is _{B (C 6 X 5) 4} - is preferably represented by. It is preferable that the photocationic polymerization initiator which releases the organic acid ion containing a boron atom is a compound which has an anionic part represented by following formula (1).

  In the above formula (1), X represents a halogen atom. It is preferable that X in the said Formula (1) is a chlorine atom, a bromine atom, or a fluorine atom, and it is more preferable that it is a fluorine atom.

Anionic portion of the cationic photopolymerization initiator is _{B (C 6 F 5) 4} - is preferably represented by. The photocationic polymerization initiator that releases the organic acid ion containing a boron atom is more preferably a compound having an anionic moiety represented by the following formula (1A).

  Further, the type of the photocationic polymerization initiator may be an ionic photoacid generation type or a non-ionic photoacid generation type.

  The antimony complex is not particularly limited, but is preferably a sulfonium salt. As the sulfonium salt which is the above-mentioned antimony complex, tetraphenyl (diphenyl sulfide-4,4'-diyl) bissulfonium di (antimony hexafluoride), tetra (4-methokitophenyl) [diphenyl sulfide-4,4 ' -Diyl] bissulfonium di (antimony hexafluoride), diphenyl (4-phenylthiophenyl) sulfonium antimony pentafluoride, and di (4-methoxyphenyl) [4-phenylthiophenyl] sulfonium antimony pentafluoride Etc.

  As a commercial item of the above-mentioned antimony complex, Adeka optomer SP-170 (made by ADEKA) etc. are mentioned, for example.

  As a commercial item of the salt which has a hexafluorophosphorus ion, WPI-113 (made by Wako Pure Chemical Industries Ltd.), CPI-100P (made by San-Apro) etc. are mentioned, for example.

  The content of the photocationic polymerization initiator is not particularly limited. The content of the photo cationic polymerization initiator is preferably 0.05 parts by weight or more, more preferably 0.15 parts by weight or more, preferably 2 parts by weight or less, with respect to 100 parts by weight of the photocurable compound. Preferably, it is 1 part by weight or less. A photocurable electrically conductive material photocures suitably that content of the said photocationic polymerization initiator is more than the said minimum and below the said upper limit.

Photo-curing retarder:
The photocuring retarder suppresses the progress of curing of the photocurable conductive material in a relatively short time after being irradiated with light. The photocurable compound does not contain a photocuring retarder.

  Examples of the photo-curing retarder include polyether compounds, polyglycerol compounds and tertiary amine compounds. The photocuring retarder is preferably a tertiary amine compound. In particular, when the photo-curing retarder is a tertiary amine compound, voids can be further prevented from being generated at the bonding interface, and connection reliability between the connection target member and the cured product of the conductive material can be further enhanced. . Since the photocuring retarder is a tertiary amine compound, a void is formed at the bonding interface even if L / S indicating the width of the line (L) with the electrode and the space of the space (S) without the electrode is small. Thus, the connection reliability between the connection target member and the cured product of the conductive material can be effectively enhanced.

  As said polyether compound, a polyol compound, a crown ether compound, etc. are mentioned. Among them, crown ether compounds are preferable.

  Examples of the polyol compound include polyethylene glycol, polypropylene glycol, and polytetramethylene glycol.

  The crown ether compound is not particularly limited, and, for example, 12-crown-4, 15-crown-5, 18-crown-6, 24-crown-8, and a structure represented by the following formula (31) Compounds etc. may be mentioned.

  In said Formula (31), R1-R12 respectively represents a hydrogen atom or a C1-C20 substituted or unsubstituted alkyl group. However, at least one of R1 to R12 represents an alkyl group having 1 to 20 carbon atoms. The substituted or unsubstituted alkyl group is one or more functions selected from the group consisting of an alkoxyl group having 1 to 20 carbon atoms, a halogen atom, a hydroxyl group, a carboxyl group, and a carboxylic acid alkyl ester group having 1 to 20 carbon atoms It may be substituted by a group, and further, adjacent Rn and Rn + 1 (wherein n represents an even number of 1 to 12) may jointly form a cyclic alkyl skeleton. The said C1-C20 alkoxyl group may be linear, and may be branched.

  Among the compounds represented by the above formula (31), compounds having at least one cyclohexyl group are preferable. The presence of the cyclohexyl group stabilizes the skeleton of the crown ether and enhances the delay effect.

  As a compound which has a cyclohexyl group and is represented by the said Formula (31), the compound specifically represented by following formula (31A) is mentioned.

  The compound represented by the above formula (31A) has two cyclohexyl groups at positions symmetrical to a line passing through the center of the 18-crown-6-ether molecule. For this reason, it is considered that the delay effect is enhanced without causing distortion or the like in the skeleton of the 18-crown-6-ether molecule.

  Examples of the polyglycerol compound include polyglycerol polyglycidyl ether and polyglycerol methacrylate.

  Examples of the tertiary amine compound include triethylamine, trimethylamine, diisopropylethylamine, 1,3,5-triazine-2,4,6-trithiol, triglycidyl isocyanurate and 2,4,6-tri (glycidyloxy) -1, 3,5-triazine etc. are mentioned.

  The tertiary amine compound is preferably a compound having a triazine skeleton from the viewpoint of making it more difficult to form voids at the bonding interface and further enhancing the adhesion reliability. The nitrogen atom in the triazine skeleton is preferably a nitrogen atom of a tertiary amine.

  The tertiary amine compound preferably has a cationically polymerizable group from the viewpoint of making it more difficult to form voids at the bonding interface and further enhancing the adhesion reliability.

  An epoxy group, a vinyl group, an oxetane group etc. are mentioned as said cationically polymerizable group.

  It is preferable that the above-mentioned cationically polymerizable group is an epoxy group from the viewpoint of making it more difficult to form voids at the bonding interface and further improving the adhesion reliability.

  The photocuring retarder adheres to the surface of the conductive particles. In the photocurable conductive material, the conductive particles and the photocurable retarder are contained in the photocurable conductive material in a state where the photocurable retarder is attached to the surface of the conductive particles. It is preferable that the said electroconductive particle and the said photocuring retarder are mix | blended, after making the said photocuring retarder adhere on the surface of the said electroconductive particle. The photoconductive conductive material is obtained by the conductive particles and the photocuring retarder being mixed with other components after the photocuring retarder is attached to the surface of the conductive particles. Is preferred.

  The content of the photocuring retarder is not particularly limited. The content of the photo-curing retarder is preferably 0.1 parts by weight or more, more preferably 0.5 parts by weight or more, preferably 10 parts by weight or less, relative to 100 parts by weight of the photo-curable compound. Is 5 parts by weight or less. When the content of the photocuring retarder is at least the lower limit and the upper limit, the photocurable conductive material is appropriately delayed and photocured.

  The content of the photocuring retarder is preferably 0.01% by weight or more, more preferably 0.1% by weight or more, still more preferably 1% of the total of 100% by weight of the conductive particles and the photocuring retarder. % By weight or more, particularly preferably 3% by weight or more, most preferably 10% by weight or more, preferably 50% by weight or less, more preferably 30% by weight or less, still more preferably 20% by weight or less. When the content of the photocuring retarder is at least the lower limit and the upper limit, the photocurable conductive material is appropriately delayed and photocured. In addition, connection reliability is further enhanced.

Thermosetting compound:
The thermosetting compound has a thermosetting property. Only one type of the thermosetting compound may be used, or two or more types may be used in combination.

  The thermosetting compound may have thermosetting and photocuring properties, and may not have photocuring properties.

  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 easily controlling the curing of the photocurable conductive material or further enhancing the conduction reliability in the connection structure, the thermosetting compound is a thermosetting compound having an epoxy group or thiirane group. It is preferable to include a thermosetting compound having a thiirane group. The thermosetting compound having an epoxy group is an epoxy compound. The thermosetting compound having a thiirane group is an episulfide compound. From the viewpoint of enhancing the curability of the photocurable conductive material, the content of the compound having an epoxy group or thiirane group is preferably 10% by weight or more, more preferably 20% by weight in 100% by weight of the thermosetting compound. % Or more and 100% by weight or less. The total amount of the thermosetting compound may be a compound having the epoxy group or thiirane group.

  The above-mentioned episulfide compound has thiirane group instead of epoxy group, so it can be cured rapidly at low temperature. That is, the episulfide compound having a thiirane group can be cured at a lower temperature derived from the thiirane group as compared to the epoxy compound having an epoxy group.

  The thermosetting compound having the epoxy group or thiirane group preferably has an aromatic ring. The aromatic ring is preferably a benzene ring, a naphthalene ring or an anthracene ring, and more preferably a benzene ring or a naphthalene ring. In addition, a naphthalene ring is preferable because it has a planar structure and can be cured more rapidly.

  The thermosetting compound may contain a phenoxy resin. In this case, a phenoxy resin and a thermosetting compound having the above-mentioned epoxy group or thiirane group may be used in combination. In this case, the thermosetting compound having an epoxy group or thiirane group is preferably not a phenoxy resin.

  From the viewpoint of further improving the conduction reliability between the electrodes in the connection structure, the weight average molecular weight of the phenoxy resin is preferably 20000 or more, and preferably 70000 or less.

  The said weight average molecular weight shows the weight average molecular weight in polystyrene conversion measured by gel permeation chromatography (GPC).

  When the phenoxy resin and the thermosetting compound having the epoxy group or thiirane group are used in combination, the photocurable conductive material includes the phenoxy resin and the thermosetting compound having the epoxy group or thiirane group. Is preferably contained in a weight ratio of 1:99 to 99: 1, more preferably 10:90 to 90:10, still more preferably 20:80 to 80:20, still more preferably 30:70 to It is particularly preferred to include at 70:30.

  When a thermosetting compound is used, the compounding ratio of the photocurable compound to the thermosetting compound is appropriately adjusted according to the types of the photocurable compound and the thermosetting compound. The compounding ratio of the photocurable compound to the thermosetting compound may be 1:99 to 99: 1, 10:90 to 90:10, or 20:80 to 80:20. It may be 30:70 to 70:30.

  The content of the thermosetting compound is preferably 0% by weight (not contained) or more, more preferably 0.3% by weight or more, preferably 50% by weight or less, in 100% by weight of the photocurable conductive material. Preferably it is 30 weight% or less. The photocurable conductive material is appropriately heat-cured when the thermosetting compound is contained and the content of the thermosetting compound is not less than the lower limit and not more than the upper limit.

Thermosetting agent:
The said thermosetting agent is not specifically limited. A conventionally known thermosetting agent can be used as the thermosetting agent. Examples of the thermosetting agent include imidazole curing agent, amine curing agent, phenol curing agent, polythiol curing agent and acid anhydride. Only one type of the thermosetting agent may be used, or two or more types may be used in combination.

  The heat curing agent is preferably an imidazole curing agent, a polythiol curing agent or an amine curing agent because the photocurable conductive material can be cured more rapidly at low temperature. In addition, since the storage stability of the photocurable conductive material can be enhanced, a latent curing agent is preferred. The latent curing agent is preferably a latent imidazole curing agent, a latent polythiol curing agent or a latent amine curing agent. The thermosetting agent may be coated with a polymer substance such as a polyurethane resin or a polyester resin.

  The imidazole curing agent is not particularly limited, and 2-methylimidazole, 2-ethyl-4-methylimidazole, 1-cyanoethyl-2-phenylimidazole, 1-cyanoethyl-2-phenylimidazolium trimellitate, 2, 4-Diamino-6- [2′-methylimidazolyl- (1 ′)]-ethyl-s-triazine and 2,4-diamino-6- [2′-methylimidazolyl- (1 ′)]-ethyl-s- The triazine isocyanuric acid adduct etc. are mentioned.

  The polythiol curing agent is not particularly limited, and examples thereof include trimethylolpropane tris-3-mercaptopropionate, pentaerythritol tetrakis-3-mercaptopropionate and dipentaerythritol hexa-3-mercaptopropionate. .

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

  The content of the thermosetting agent is not particularly limited. The content of the thermosetting agent is preferably 5 parts by weight or more, more preferably 10 parts by weight or more, preferably 40 parts by weight or less, more preferably 30 parts by weight or less, based on 100 parts by weight of the thermosetting compound. More preferably, it is at most 20 parts by weight. When the content of the thermosetting agent is at least the lower limit and the upper limit, the photocurable conductive material is sufficiently thermally cured.

(Other details of connection structure)
Specific examples of the connection target member include electronic components such as a semiconductor chip, a capacitor, and a diode, and electronic components that are circuit substrates such as a printed circuit board, a flexible printed circuit, a glass epoxy substrate, and a glass substrate. The connection target member is preferably an electronic component.

  The method for manufacturing a connection structure according to the present invention and the connection structure according to the present invention include, 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 The present invention can be applied to COF (Chip on Film), connection between a semiconductor chip and a glass substrate (COG (Chip on Glass)), connection between a flexible printed substrate and a glass epoxy substrate (FOB (Film on Board)), and the like. Among them, the photocurable conductive material is suitable for FOG applications or COG applications, and more suitable for COG applications. The photocurable conductive material is preferably applied to connection between a flexible printed substrate and a glass substrate or connection between a semiconductor chip and a glass substrate, and more preferably applied to connection between a semiconductor chip and a glass substrate.

  In the method for manufacturing a connection structure according to the present invention and the connection structure according to the present invention, the combination of the first connection target member and the second connection target member is a glass substrate and a flexible printed circuit board or a semiconductor chip It is preferable that it is a combination of, and it is more preferable that it is a combination of a glass substrate and a semiconductor chip. Either the first connection target member or the second connection target member may be a glass substrate, or may be a flexible printed circuit or a semiconductor chip.

  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 silver electrode, a molybdenum electrode, a tungsten electrode, etc. are mentioned. When the connection target member is a flexible printed board, the electrode is preferably a gold electrode, a nickel electrode, a tin 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 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.

  Hereinafter, the present invention will be specifically described by way of examples and comparative examples. The invention is not limited to the following examples.

Example 1
(1) Preparation of Conductive Particle Complex A conductive particle was prepared in which the surface of a divinylbenzene resin particle (average particle diameter: 3 μm) was coated with a nickel plating layer (thickness: 0.1 μm). A conductive particle is made to adhere the diglycidyl monoallyl isocyanurate ("MA-DGIC" manufactured by Shikoku Kasei Kogyo Co., Ltd.) (a compound having a triazine skeleton and an epoxy group) as a light curing retarder on the surface of the conductive particle. The complex was obtained. The obtained conductive particle composite contains 99% by weight of conductive particles and 1% by weight of a light curing retarder.

(2) Preparation of anisotropic conductive film (photocurable conductive material) 45 parts by weight of phenoxy resin ("PKHC" manufactured by Union Carbide) and 25 weight of bisphenol A type epoxy resin ("Epikote 1009" manufactured by Mitsubishi Chemical Corporation) Parts, 10 parts by weight of a cationic photopolymerization initiator ("Sanaid SI-80" manufactured by Sanshin Chemical Industries, Ltd.), 2 parts by weight of a silane coupling agent ("SH6040" manufactured by Toray Dow Corning Silicones), and conductive particles 15 parts by weight of the composite (14.85 parts by weight of conductive particles and 0.15 parts by weight of a photocuring retarder) were mixed with toluene to obtain a resin composition having a solid content of 50%. The obtained resin composition was applied onto release-treated polyethylene terephthalate and the solvent was dried to obtain an anisotropic conductive film having a thickness of 20 μm.

(3) Preparation of Connection Structure A transparent glass substrate (first connection target member) having a multilayer electrode pattern of Ti—Al—Ti of 10 μm / 10 μm in which L / S is 10 μm was prepared. In addition, a semiconductor chip (second connection target member) having a gold electrode pattern of L / S of 10 μm / 10 μm on the lower surface was prepared.

The obtained anisotropic conductive film was attached to the chip mounting portion on the transparent glass substrate. Next, from the upper side of the anisotropic conductive film, ultraviolet irradiation with a wavelength of 365 nm was performed such that the light irradiation amount was 100 mJ / cm ² (first light irradiation step).

60 seconds after the first light irradiation, the semiconductor chip was laminated on the anisotropic conductive film so that the electrodes face each other. Thereafter, the pressure heating head was mounted on the top surface of the semiconductor chip while adjusting the temperature of the head. Regarding the connection conditions, heating and pressing for 5 seconds at 110 ° C. and 50 MPa (first heat application step) and ultraviolet irradiation from the transparent glass substrate side were simultaneously performed. Specifically, ultraviolet light with a wavelength of 365 nm was irradiated so as to have a light irradiation amount of 600 mJ / cm ² after 2 seconds after starting heating and pressing only (second light irradiation step). Heating and pressing and ultraviolet irradiation were simultaneously ended 10 seconds after the start of heating and pressing. Then the pressure was released. Then, it heated at 100 degreeC for 1 hour (2nd heat provision process), and obtained the connection structure.

(Example 2)
The anisotropic conductive film and the connection structure were obtained like Example 1 except having changed the photocationic polymerization initiator into "CPI-101A" by San-Apro corporation make.

(Example 3)
An anisotropic conductive film and a connecting structure were obtained in the same manner as in Example 1 except that the photocuring retarder was changed to 1,3,5-triazine-2,4,6-trithiol.

(Example 4)
The anisotropic conductive film and the connection structure were obtained like Example 1 except having changed the photocuring retarder into the triethylamine.

(Comparative example 1)
In Comparative Example 1, the conductive particles and the light curing retarder were separately used without being complexed.

  45 parts by weight of phenoxy resin ("PKHC" manufactured by Union Carbide Co., Ltd.), 25 parts by weight of bisphenol A type epoxy resin ("Epicoat 1009" manufactured by Mitsubishi Chemical Co., Ltd.), and cationic photopolymerization initiator SI-80 ′ ′) 10 parts by weight, 2 parts by weight of a silane coupling agent (“SH 6040” manufactured by Toray Dow Corning Silicone Co., Ltd.), and a photo-curing retarder (diglycidyl monoallyl isocyanurate (MA 1 part by weight of DGIC ") (compound having a triazine skeleton and an epoxy group) and 20 parts by weight of conductive particles were mixed with toluene to obtain a resin composition having a solid content of 50%. The obtained resin composition was applied onto release-treated polyethylene terephthalate and the solvent was dried to obtain an anisotropic conductive film having a thickness of 20 μm. In addition, the electroconductive particle used is an electroconductive particle by which the surface of divinylbenzene resin particle (average particle diameter 3 micrometers) was coat | covered with the nickel plating layer (thickness 0.1 micrometer).

(Comparative example 2)
An anisotropic conductive film and a connecting structure were obtained in the same manner as in Comparative Example 1 except that the photocuring retarder was changed to 1,3,5-triazine-2,4,6-trithiol.

(Comparative example 3)
An anisotropic conductive film and a connecting structure were obtained in the same manner as in Comparative Example 1 except that the photocuring retarder was changed to triethylamine.

(Comparative example 4)
An anisotropic conductive film was obtained in the same manner as in Example 1 except that the photocuring retarder was not used. A connection structure was obtained in the same manner as in Example 1 except that the first light irradiation step was not performed.

(Comparative example 5)
An anisotropic conductive film and a connection structure were obtained in the same manner as in Example 1 except that the photocationic polymerization initiator was changed to a photoradical generator ("IRGACURE 819" manufactured by Ciba Japan).

(Example 5)
After nickel particles (100 nm) as a core substance were attached to the surface of divinylbenzene resin particles (average particle diameter 3 μm), conductive particles with protrusions coated with a nickel plating layer (thickness 0.1 μm) were prepared. An anisotropic conductive film and a connecting structure were obtained in the same manner as in Example 1 except that the conductive particles were changed to the conductive particles with protrusions.

(Example 6)
The nickel particles (average particle diameter 100 nm) as the core material are attached to the surface of the divinylbenzene resin particles (average particle diameter 3 μm), and then the conductive particles with protrusions coated with the nickel plating layer (thickness 0.1 μm) Obtained. The surface of this conductive particle is further uniformly coated with an organic insulating particle (insulating particle having an average particle diameter of 200 nm by a polymer of MMA (methyl methacrylate)), and the insulating particle coating and the conductive particle having a protrusion are provided. I got In the obtained insulating particle coating and the conductive particles with projections, about 60% of the surface area of the conductive particles was covered by the insulating particles. An anisotropic conductive film and a connecting structure were obtained in the same manner as in Example 1 except that the conductive particles were changed to the insulating particle coating and the conductive particles with protrusions.

(Example 7)
The electroconductive particle in which the surface of the divinylbenzene resin particle (average particle diameter 2.5 micrometers) was coat | covered with the nickel plating layer (thickness 0.1 micrometer) was prepared. An anisotropic conductive film and a connecting structure were obtained in the same manner as in Example 1 except that the conductive particles were changed to the conductive particles with protrusions.

(Example 8)
In the same manner as in Example 1, except that the weight ratio of the conductive particles to the photocuring retarder in the conductive particle composite is changed to 95% by weight of the conductive particles and 5% by weight of the photocuring retarder, An anisotropic conductive film and a connection structure were obtained.

(Example 9)
In the same manner as in Example 1 except that the weight ratio of the conductive particles to the photocuring retarder in the conductive particle composite is changed to 90% by weight of the conductive particles and 10% by weight of the photocuring retarder, An anisotropic conductive film and a connection structure were obtained.

(Evaluation)
(1) Viscosity The viscosity η1 of the photocurable conductive material before the first light irradiation, the ultraviolet light irradiation of wavelength 365 nm, and the light irradiation amount of 150 mJ / cm ² (light irradiation intensity at the time of connection structure preparation) The viscosity η2 of the photocurable conductive material after 60 seconds of irradiation was measured. For measurement of viscosity, “AR-2000 ex” manufactured by TA Instruments Co., Ltd. was used. The viscosity was determined based on the following criteria.

[Criteria for judging viscosity]
A: 2 2/1 1 is 1.3 or less B: / 2/1 1 is more than 1.3, 1.5 or less C: 2 2/1 1 is more than 1.5

(2) Presence of Voids The cross section of the obtained connection structure was observed, and it was observed with an optical microscope whether or not a void was generated in the connection portion where the photocurable conductive material was cured. The presence or absence of a void was determined based on the following criteria. If there are no voids, the connection reliability is high, and if the number of voids is small, the connection reliability is high.

[Criteria for determining the presence or absence of a void]
○: No void Δ: Slightly voided, but L / S of electrode, no void above pitch, void: Void larger than size between adjacent electrodes

(3) Connection state between the electrode and the conductive particle By observing the cross section of the obtained connection structure, the connection portion in which the photocurable conductive material is cured is sandwiched between the electrode and the conductive particle. It was evaluated whether there was a part.

[Connection state between electrode and conductive particle]
○: no cured connection of the photocurable conductive material is sandwiched between the electrode and the conductive particles :: light curing to the extent that connection failure does not occur between the electrode and the conductive particles The cured connection part of the conductive conductive material is slightly pinched. Δ: The cured connection part of the photocurable conductive material is slightly pinched between the electrode and the conductive particles to the extent that connection failure does not occur. X: The connection portion in which the photocurable conductive material is cured is sandwiched between the electrode and the conductive particle to a certain extent that connection failure may occur.

(4) Warpage of Second Connection Target Member In the obtained connection structure, the warpage amount of the semiconductor chip as the second connection target member was measured. The connection structure was disposed on a horizontal surface, and the difference between the maximum height position and the minimum height position in the measurement at the long side 25 mm of the semiconductor chip as the second connection target member was taken as the amount of warpage. Warpage of the second connection target member was determined according to the following criteria. In addition, when the curvature amount of a 2nd connection object member was large, it confirmed that there existed a tendency for a 2nd connection object member to peel easily from a connection part.

[Criteria for Determining Warpage of Second Connection Target Member]
○: Warpage of the second connection target member is less than 10 μm ○: Warpage of the second connection target member is 10 μm or more and less than 15 μm Δ: Warpage of the second connection target member is 15 μm or more and less than 20 μm × : Warpage of second connection target member is 20 μm or more

(5) Connection reliability between electrodes The resistance value between the electrodes in the obtained connection structure was measured by the four-terminal method. Thereafter, the resistance value between electrodes in the connection structure processed for 500 hours in an environment of 85 ° C. and 85% humidity was measured again. The connection reliability between the electrodes was evaluated according to the following evaluation criteria in accordance with the rate of increase in resistance after being left in a high temperature and high humidity environment.

[Criteria for connection reliability between electrodes]
○○○: Resistance value rise magnification less than 1 × ○○: Resistance value rise magnification 1 × to 2 × ○: Resistance value rise magnification 2 × to 4 × Δ: Resistance value rise magnification 4 times Above, less than 8 times ×: The resistance value increase magnification is 8 times or more

(6) Conduction reliability between electrodes The resistance value between electrodes in the obtained connection structure was measured by the four-terminal method. The conduction reliability between the electrodes was determined based on the following criteria.

[Criteria for reliability of conduction between electrodes]
○ ○: resistance value less than 1.5Ω ○: resistance value 1.5Ω or more and less than 2.0Ω Δ: resistance value 2.0Ω or more and less than 2.5Ω ×: resistance value 2.5Ω or more

  The results are shown in Table 1 below.

  In the first embodiment and the fifth and sixth embodiments, the evaluation result of the connection reliability and the conduction reliability is “○”, but the resistance value increase rate of the connection reliability is the same as that of the fifth embodiment However, the resistance value of conduction reliability was smaller in the fifth and sixth embodiments than in the first embodiment. Further, in Example 6, the insulation reliability between the electrodes adjacent in the lateral direction was superior to that in Examples 1 and 5.

DESCRIPTION OF SYMBOLS 1 ... Connection structure 2 ... 1st connection object member 2a ... 1st electrode 3 ... 2nd connection object member 3a ... 2nd electrode 4 ... Connection part 4A ... Photocurable conductive material layer 4B ... 1st Photocurable conductive material layer 4C subjected to light irradiation: Photocurable conductive material layer subjected to second light irradiation and first heat application 11: Cured product of light curing component 21: Conductive particles 22 ... conductive particle composite 31 ... base material particle 32 ... conductive portion 33 ... light curing retarder 51 ... thermocompression bonding head

Claims (12)

It is a conductive material that is used for the connection of a connection target member having an electrode on the surface, and has a photocurable property,
Conductive particles,
A photocurable compound,
Photo cationic polymerization initiator,
Containing a light curing retarder,
The photocuring retarder is attached to the surface of the conductive particles ,
Photocurable, wherein the conductive particles and the photocuring retarder are contained in a photocurable conductive material as a conductive particle composite in which the photocuring retarder is attached to the surface of the conductive particles Conductive material. The photo cationic polymerization initiator is a photo cationic polymerization initiator which generates an acid upon irradiation with light,
The photocurable conductive material according to claim 1, wherein the photocuring retarder is capable of capturing an acid generated from a cationic photopolymerization initiator. A first connection target member having a first electrode on the surface and a second connection target member having a second electrode on the surface are connected, and the first electrode and the second electrode are electrically connected. Are used to obtain connection structure,
The photocurable conductive material is disposed on the surface of the first connection target member, and then the first light irradiation is performed on the photocurable conductive material from the side opposite to the first connection target member side. Then, the first connection target member of the photocurable conductive material subjected to the first light irradiation such that the conductive particle is positioned between the first electrode and the second electrode The second connection target member is disposed on the surface opposite to the side, and the second light irradiation and heat are applied to the photocurable conductive material when or after the second connection target member is disposed. The photocuring according to claim 1 or 2 , which is used to obtain the connection structure through the step of at least one of the application of the photocurable conductive material to form a cured cured product of the photocurable conductive material. Conductive material. When or after the second connection target member is disposed, the second light irradiation is performed on the photocurable conductive material to form a cured product in which the photocurable conductive material is cured. The photocurable conductive material according to claim 3 , which is used to obtain the connection structure. When or after the second connection target member is disposed, heat is applied to the photocurable conductive material to form a cured product in which the photocurable conductive material is cured. The photocurable conductive material according to claim 3 , which is used to obtain a connection structure. When or after the second connection target member is disposed, the second light irradiation is performed on the photocurable conductive material and heat is applied to the photocurable conductive material to perform photocuring The photocurable conductive material according to claim 3 , which is used to obtain the connection structure through the step of forming a cured cured product of the conductive conductive material. A conductive material that has photo-setting and thermosetting properties,
The photocurable conductive material according to any one of claims 1 to 3 , 5 and 6 , comprising a thermosetting compound and a thermosetting agent. 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 connecting portion connecting the first connection target member and the second connection target member;
The connection portion is formed by curing the photocurable conductive material according to any one of claims 1 to 7 ,
The connection structure which the said 1st electrode and the said 2nd electrode are electrically connected by the said electroconductive particle. A photocurable conductive material according to any one of claims 1 to 7 is used, and
Using a first connection target member having a first electrode on the surface, and a second connection target member having a second electrode on the surface,
Placing the photocurable conductive material on the surface of the first connection target member;
Applying a first light to the photocurable conductive material disposed on the surface of the first connection target member from the side opposite to the first connection target member side;
The first connection target member side of the photocurable conductive material subjected to the first light irradiation so that the conductive particles are positioned between the first electrode and the second electrode; Placing the second connection object on the opposite surface,
And a step of performing at least one of the second light irradiation and the application of heat to the photocurable conductive material during or after the arrangement of the second connection target member,
A connection portion connecting the first connection target member and the second connection target member is formed of a cured product of the photocurable conductive material, and the first electrode and the second electrode. And a method of manufacturing a connection structure, wherein the conductive particles electrically connect. The second light irradiation step, after placement upon or arrangement of the second connection object member, a second light irradiation step of performing a second light irradiating the photocurable conductive material, to claim 9 The manufacturing method of the connection structure of a statement. 10. The connection structure according to claim 9 , wherein the second light irradiation step is a step of applying heat to the photocurable conductive material at the time of or after the placement of the second connection target member. How to make the body. At the time of arrangement of the second connection target member or after the arrangement of the second connection target member, the second light irradiation step applies the second light to the photocurable conductive material, and applies heat to the photocurable conductive material. The manufacturing method of the connection structure of Claim 9 which is the 2nd light irradiation and the application process of a heat | fever which are performed.

Images