JP2007317563A - Circuit connecting adhesive - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a circuit connecting adhesive capable of enhancing connection reliability between a protruding electrode of an electronic component and a wiring electrode of a circuit board, when connecting the electronic component to the circuit board through the circuit connecting adhesive. <P>SOLUTION: The protruding electrode 5 of the electronic component 3 is connected to the wiring electrode 4 of the circuit board 1 through the circuit connecting adhesive 2 having at least one kind of a thermosetting resin selected from an epoxy resin, a phenol resin, a polyurethane resin, an unsaturated polyester resin, and a urea resin and containing conductive particles and a silane coupling agent. The silane coupling agent contained in the circuit connecting adhesive 2 contains a silane coupling agent containing a mercapto group. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to an adhesive for circuit connection for bonding and electrically connecting a substrate, an electronic component, or the like provided with electrodes, circuits, and the like.

  In recent years, electronic devices have been miniaturized and highly functionalized, and connection terminals in components have been miniaturized. For this reason, in the electronics mounting field, various adhesives for circuit connection that can easily connect such terminals are widely used. For example, it is used to join electronic components such as IC chips and flexible printed circuit boards (FPC), and electronic components and circuit boards such as glass substrates on which ITO electrode circuits are formed.

  This adhesive for circuit connection is a film or paste adhesive in which conductive particles are dispersed in an insulating resin composition. It is sandwiched between connected objects, heated and pressurized, and connected. Glue the object. That is, the resin in the adhesive flows due to heating and pressurization. For example, the protrusion electrodes (or bumps) formed on the surface of the electronic component and the wiring electrodes such as the ITO electrode formed on the surface of the circuit board At the same time as the gap is sealed, a part of the conductive particles is engaged between the protruding electrode and the wiring electrode facing each other, thereby achieving electrical connection. And in the adhesive for circuit connection, it adjoins in the surface direction of the adhesive performance for circuit connection, and the conduction | electrical_connection performance which makes low the resistance (conducting resistance) between the electrodes opposite to the thickness direction of the said circuit connection adhesive. Insulation performance is required to increase the resistance (insulation resistance) between the electrodes.

  Here, in a circuit board such as a glass substrate, since there is little unevenness on the surface, when connecting an electronic component and a circuit board via an adhesive, a so-called anchor effect is hardly expected, and the circuit board and the thermosetting There is a problem that the adhesiveness with the adhesive resin becomes poor.

Therefore, a method of adding a coupling agent to the adhesive is generally performed in order to improve the interfacial adhesive force between the circuit board and the thermosetting resin. More specifically, for example, an epoxy-based insulating adhesive having an epoxy resin as a thermosetting resin as a main component, a silane coupling agent and a curing agent, and further metal-coated resin particles. A method of connecting an electronic component and a circuit board via a conductive adhesive is disclosed (for example, see Patent Document 1).
JP 2000-306927 A

  However, in the conventional adhesive for circuit connection, metal protruding electrodes (for example, gold-plated bumps) formed on the surface of the electronic component and metal wiring electrodes (for example, formed on the surface of the circuit board) Since the adhesive force between the ITO electrode) and the thermosetting resin such as epoxy resin is low, peeling of these electrodes at the bonding interface between the circuit connecting adhesive, the wiring electrode, and the protruding electrode is likely to occur. In addition, in order to obtain sufficient adhesion between the circuit board and the thermosetting resin, it is necessary to add a large amount of silane coupling agent, so the physical properties of the thermosetting resin such as reduced moisture resistance and reduced heat resistance. May be adversely affected. Therefore, there is a problem that the connection reliability between the circuit board and the electronic component is lowered.

  Therefore, the present invention has been made in view of the above-described problems, and when connecting an electronic component and a circuit board via an adhesive for circuit connection, the protruding electrode of the electronic component and the wiring electrode of the circuit board are connected. An object of the present invention is to provide an adhesive for circuit connection that can improve connection reliability.

  In order to achieve the above object, in the invention according to claim 1, the main component is at least one thermosetting resin selected from an epoxy resin, a phenol resin, a polyurethane resin, an unsaturated polyester resin, and a urea resin. An adhesive for circuit connection containing conductive particles and a silane coupling agent, wherein the silane coupling agent includes a silane coupling agent having a mercapto group.

  According to this configuration, for example, the main component is at least one thermosetting resin selected from an epoxy resin, a phenol resin, a polyurethane resin, an unsaturated polyester resin, and a urea resin, conductive particles, and a silane coupling agent. When connecting the protruding electrode of the electronic component to the wiring electrode of the circuit board by performing a heat and pressure treatment via the circuit connecting adhesive containing the silane coupling agent mercapto group and a metal The surface of the protruding electrode (for example, gold plating bump) and the metallic wiring electrode (for example, ITO electrode) react to form a strong chemical bond between the surface of the wiring electrode and the protruding electrode and the coupling agent. Become. Therefore, when connecting the circuit board and the electronic component via the circuit connecting adhesive, the thermosetting resin of the circuit connecting adhesive, the metal wiring electrode, and the protruding electrode can be firmly bonded. Thus, the adhesive force between the thermosetting resin of the circuit connecting adhesive, the metal wiring electrode, and the protruding electrode can be improved. As a result, it is possible to prevent peeling of the wiring electrode and the protruding electrode at the bonding interface between the circuit connecting adhesive and the wiring electrode and the protruding electrode, and to prevent a decrease in moisture resistance and heat resistance of the thermosetting resin. Is possible. Further, it is possible to improve the connection reliability between the circuit board and the electronic component when connecting the circuit board and the electronic component via the circuit connecting adhesive.

  Invention of Claim 2 is the thermosetting resin which is the adhesive for circuit connection of Claim 1, Comprising: The compounding quantity of the silane coupling agent which has a mercapto group is contained in the adhesive for circuit connection It is characterized by being not less than 0.1 wt% and not more than 5 wt% of the total weight.

  According to this configuration, it is possible to effectively exert a strong chemical bond between the surface of the wiring electrode and the protruding electrode and the coupling agent having a mercapto group, and the thermosetting property of the adhesive for circuit connection. It becomes possible to effectively prevent a decrease in moisture resistance and heat resistance of the resin.

  Note that, as in the invention described in claim 3, the adhesive for circuit connection according to claim 1 or 2, wherein the silane coupling agent further includes a silane coupling agent having an epoxy group. Is preferred. This is because the epoxy group reacts with the resin component in the adhesive for circuit connection and is taken into the polymer network, so that the resin component of the adhesive for circuit connection and the circuit board such as a glass substrate are made stronger. Because it can be tied.

  The invention according to claim 4 is the total formulation of the adhesive for circuit connection according to claim 3, comprising a silane coupling agent having a mercapto group and a silane coupling agent having an epoxy group. The amount is from 0.1% by weight to 10% by weight of the total weight of the thermosetting resin contained in the circuit connecting adhesive.

  According to this configuration, even when the silane coupling agent contained in the circuit connecting adhesive includes a silane coupling agent having an epoxy group in addition to the silane coupling agent having a mercapto group, the wiring electrode In addition, it is possible to effectively exert a strong chemical bond between the surface of the protruding electrode and the coupling agent having a mercapto group, and the moisture resistance and heat resistance of the thermosetting resin of the adhesive for circuit connection. It is possible to effectively prevent the decrease.

  The invention according to claim 5 is the adhesive for circuit connection according to any one of claims 1 to 4, wherein the conductive particles have an aspect ratio of 5 or more.

  According to this configuration, since the adhesive for circuit connection contains conductive particles having a high contact probability, it is possible to conductively connect the wiring electrode and the protruding electrode without increasing the blending amount of the conductive particles. .

  A sixth aspect of the present invention is the adhesive for circuit connection according to any one of the first to fifth aspects, wherein the adhesive has a film shape. According to this configuration, it becomes easy to handle the adhesive for circuit connection, and for example, by performing heat and pressure treatment via the adhesive for circuit connection, the protruding electrode of the electronic component is connected to the wiring electrode of the circuit board. Workability at the time of connecting to is improved.

  Invention of Claim 7 is the adhesive for circuit connection of Claim 6, Comprising: The major axis direction of electroconductive particle was orientated in the thickness direction of the adhesive agent which has a film shape, It is characterized by the above-mentioned. . According to this configuration, it is possible to electrically connect a large number of wiring electrodes and protruding electrodes at a time and independently, while maintaining insulation between adjacent electrodes and preventing a short circuit.

  ADVANTAGE OF THE INVENTION According to this invention, when connecting a circuit board and an electronic component via the adhesive agent for circuit connection, it becomes possible to improve the connection reliability of a circuit board and an electronic component.

  Hereinafter, a preferred embodiment of the present invention will be described. FIG. 1 is a cross-sectional view showing a circuit board on which an electronic component is mounted using an adhesive for circuit connection according to the present embodiment. As a method for mounting an electronic component such as an IC chip using the circuit connection adhesive of the present embodiment, for example, a flip chip method is adopted, and a circuit connection adhesive mainly composed of a thermosetting resin is used. The thermosetting resin is cured by performing heat and pressure treatment, and the protruding electrode of the electronic component is connected to the wiring electrode of the circuit board.

  More specifically, as shown in FIG. 1, a conductive material containing a thermosetting resin such as an epoxy resin as a main component, a silane coupling agent, and conductive particles on a circuit board 1 such as a glass substrate. The circuit connection adhesive 2 is placed, and while the circuit connection adhesive 2 is heated to a predetermined temperature, the circuit connection adhesive 2 is pressurized in the direction of the circuit board 1 with a predetermined pressure. Temporary bonding is performed on the substrate 1. In addition, although the adhesive agent 2 for circuit connection can be used by a paste form, the adhesive agent 2 for circuit connections which has a film shape can also be used conveniently. Next, with the electronic component 3 facing downward (face-down), while aligning the wiring electrode 4 formed on the surface of the circuit board 1 and the protruding electrode 5 formed on the surface of the electronic component 3, By placing the electronic component 3 on the circuit connecting adhesive 2, the circuit connecting adhesive 2 is interposed between the circuit board 1 and the electronic component 3. Next, the circuit connection adhesive 2 is heated at a predetermined pressure in the direction of the circuit board 1 through the electronic component 3 while the circuit connection adhesive 2 is heated to a predetermined curing temperature. The connecting adhesive 2 is melted by heating. As described above, since the circuit connecting adhesive 2 is mainly composed of a thermosetting resin, the circuit connecting adhesive 2 softens once when heated at the curing temperature described above. By continuing the heating, it will be cured. When a preset curing time of the circuit connecting adhesive 2 elapses, the state of maintaining the curing temperature of the circuit connecting adhesive 2 and the pressurized state are released, and cooling is started. The wiring electrode 4 and the protruding electrode 5 are connected via the connecting adhesive 2, and the electronic component 3 is mounted on the circuit board 1.

  Moreover, as the wiring electrode 4 of this invention, the metal ITO electrode formed on the circuit board 1, for example is used. As the protruding electrode 5, for example, a barrier metal (not shown) is formed on the electronic component 3, and a photoresist (not shown) having a predetermined opening pattern is formed on the barrier metal. Metal gold-plated bumps formed by plating gold (for example, electrolytic plating) using a resist as a mask are used.

  Here, the present embodiment is characterized in that the silane coupling agent contained in the circuit connecting adhesive 2 contains a silane coupling agent having a mercapto group. By using the circuit connection adhesive 2 containing such a mercapto group-containing silane coupling agent, the thermosetting resin is subjected to heat and pressure treatment via the circuit connection adhesive 2. When the bump electrode 5 of the electronic component 3 is connected to the wiring electrode 4 of the circuit board 1, the mercapto group of the silane coupling agent, the metal bump electrode 5, and the surface of the metal wiring electrode 4 are cured. React to form a strong chemical bond between the surface of the wiring electrode 4 and the protruding electrode 5 and the coupling agent. Therefore, when the circuit board 1 and the electronic component 3 are connected via the circuit connecting adhesive 2, the thermosetting resin of the circuit connecting adhesive 2, the metal wiring electrode 4 and the protruding electrode 5 are connected. It becomes possible to bind firmly, and the adhesive force of the thermosetting resin of the circuit connecting adhesive 2, the metal wiring electrode 4, and the protruding electrode 5 can be improved.

  In addition to the above-mentioned silane coupling agents, titanate coupling agents, aluminum coupling agents and the like can be mentioned. Among these coupling agents, the silane coupling agent does not contain a metal element and causes migration. Since possibility is low, in this embodiment, a silane coupling agent is used suitably.

  Moreover, it is preferable that the compounding quantity of the silane coupling agent which has a mercapto group is 0.1 to 5 weight% of the total weight of the thermosetting resin contained in the adhesive agent 2 for circuit connection. This is because when the compounding amount of the silane coupling agent having a mercapto group is smaller than 0.1% by weight, the chemical bonding between the surface of the wiring electrode 4 and the protruding electrode 5 and the coupling agent is sufficiently exhibited. If it is larger than 5% by weight, the moisture resistance and heat resistance of the thermosetting resin of the circuit connecting adhesive 2 are not sufficiently exhibited.

  Moreover, it is good also as a structure which uses together the silane coupling agent which has a silane coupling agent which has a mercapto group, and organic functional groups other than a mercapto group. Examples of the organic functional group contained in the silane coupling agent other than the mercapto group described above include an epoxy group, an amino group, a vinyl group, an acrylic group, a methacryl group, and a cyano group, but other than these mercapto groups. Of the functional groups, an epoxy group and an amino group are particularly preferable. Since these organic functional groups react with the resin component in the circuit connection adhesive 2 and are taken into the polymer network, the resin component of the circuit connection adhesive 2 and the circuit board 1 such as a glass substrate This is because it can be tied more firmly.

  Moreover, the compounding quantity of the silane coupling agent contained in the adhesive agent 2 for circuit connection is 0.1 to 10 weight% of the total weight of the thermosetting resin contained in the adhesive agent 2 for circuit connection. Preferably there is. With such a configuration, even when the silane coupling agent contained in the circuit connecting adhesive 2 includes a silane coupling agent having an epoxy group in addition to a silane coupling agent having a mercapto group, wiring is performed. It is possible to effectively exert a strong chemical bond between the surface of the electrode and the protruding electrode and the coupling agent having a mercapto group, and the moisture resistance and heat resistance of the thermosetting resin of the adhesive for circuit connection It is possible to effectively prevent the decrease of

  As the circuit connection adhesive 2 used in the present invention, a thermosetting resin such as an epoxy resin, which has been conventionally used to connect the circuit board 1 and the electronic component 3, is used as a main component. A particle in which a conductive particle is dispersed can be used. For example, an epoxy resin in which powder of conductive particles such as copper, silver, or graphite is dispersed can be used. Here, examples of the thermosetting resin include an epoxy resin, a phenol resin, a polyurethane resin, an unsaturated polyester resin, a urea resin, and a polyimide resin. Among these, in particular, by using an epoxy resin as the thermosetting resin, it is possible to improve the film formability, heat resistance, and adhesive strength of the circuit connecting adhesive 2. Further, the circuit connecting adhesive 2 only needs to have at least one of the above-described thermosetting resins as a main component.

  The epoxy resin to be used is not particularly limited. For example, bisphenol A type, F type, S type, AD type, or a copolymer type epoxy resin of bisphenol A type and bisphenol F type, or naphthalene type epoxy is used. Resin, novolac type epoxy resin, biphenyl type epoxy resin, dicyclopentadiene type epoxy resin and the like can be used. A phenoxy resin that is a high molecular weight epoxy resin can also be used.

  The molecular weight of the epoxy resin can be selected as appropriate in consideration of the performance required for the circuit connecting adhesive 2. When a high molecular weight epoxy resin is used, the film-forming property is high, the melt viscosity of the resin at the connection temperature can be increased, and there is an effect that the connection can be made without disturbing the orientation of conductive particles described later. On the other hand, when a low molecular weight epoxy resin is used, the crosslink density is increased and the heat resistance is improved, and the cohesive force of the resin is increased. Therefore, it is preferable to use a combination of a high molecular weight epoxy resin having a molecular weight of 15000 or more and a low molecular weight epoxy resin having a molecular weight of 2000 or less in order to balance performance. In addition, the compounding quantity of a high molecular weight epoxy resin and a low molecular weight epoxy resin can be selected suitably.

  Moreover, the adhesive agent containing a latent hardening | curing agent can be used as the adhesive agent 2 for circuit connection used for this invention. This latent curing agent is a curing agent that is excellent in storage stability at a low temperature and hardly undergoes a curing reaction at room temperature, but rapidly undergoes a curing reaction by heat or light. As this latent curing agent, imidazole series, hydrazide series, boron trifluoride-amine complex, amine imide, polyamine series, tertiary amine, alkyl urea series and other amine series, dicyandiamide series, acid anhydride series, phenol series These modified products are exemplified, and these can be used alone or as a mixture of two or more.

  Of these latent curing agents, imidazole-based latent curing agents are preferably used. As the imidazole-based latent curing agent, a known imidazole-based latent curing agent can be used. More specifically, an adduct of an imidazole compound with an epoxy resin is exemplified. Examples of the imidazole compound include imidazole, 2-methylimidazole, 2-ethylimidazole, 2-propylimidazole, 2-dodecylimidazole, 2-phenylimidazole, 2-phenyl-4-methylimidazole, and 4-methylimidazole.

  In particular, these latent curing agents coated with a polymer material such as polyurethane and polyester, a metal thin film such as nickel and copper, and an inorganic material such as calcium silicate, This is preferable because it is possible to achieve both contradictory properties of storage stability and fast curability. Therefore, a microcapsule type imidazole-based latent curing agent is particularly preferable.

  In addition, as shown in FIG. 2, an anisotropic conductive adhesive containing conductive particles 6 can be used as the circuit connecting adhesive 2. More specifically, as the anisotropic conductive adhesive, for example, an insulating thermosetting resin such as the above-described epoxy resin is a main component, and fine particles (for example, spherical metal fine particles) are contained in the resin. And a large number of fine metal particles made of spherical resin particles plated with metal), in which conductive particles 6 having a linear shape or a needle shape, or a so-called high aspect ratio shape are dispersed. Can be used. The aspect ratio referred to here is the ratio of the short diameter (the length of the cross section of the conductive particles 6) R and the long diameter (the length of the conductive particles 6) L of the conductive particles 6 shown in FIG. Say.

  Further, in this anisotropic conductive adhesive, the direction of the long diameter L of the conductive particles 6 is the magnetic field applied in the thickness direction of the anisotropic conductive adhesive when the film-shaped anisotropic conductive adhesive is formed. By passing through the film, it is preferable that the film-like anisotropic conductive adhesive is oriented in the thickness direction (the magnetic field direction and the direction of the arrow X in FIG. 2). By adopting such an orientation, between the adjacent electrodes due to the high conductive resistance in the surface direction of the film-like anisotropic conductive adhesive (the direction perpendicular to the thickness direction X and the direction of the arrow Y in FIG. 2). In this way, a large number of wiring electrodes 4 and protruding electrodes 5 are electrically conductively connected to each other at once by the low conductive resistance in the thickness direction X of the anisotropic conductive adhesive while maintaining the insulation of the electrodes. It becomes possible.

  Further, the metal fine particles used in the present invention preferably include a ferromagnetic material in part, such as a single metal having ferromagnetism, two or more kinds of alloys having ferromagnetism, a metal having ferromagnetism, and the like. It is preferably any one of an alloy with the above metal and a composite containing a metal having ferromagnetism. This is because the use of a ferromagnetic metal makes it possible to orient the conductive particles 6 using a magnetic field due to the magnetism of the metal itself. For example, nickel, iron, cobalt, and two or more kinds of alloys thereof can be used.

  The aspect ratio of the conductive particles 6 is preferably 5 or more. By using such conductive particles 6, when an anisotropic conductive adhesive is used as the circuit connection adhesive 2, the contact probability between the conductive particles 6 is increased. Therefore, the wiring electrode 4 and the protruding electrode 5 can be conductively connected without increasing the blending amount of the conductive particles 6.

  The aspect ratio of the conductive particles 6 is directly measured by a method such as observation with a CCD microscope. In the case of the conductive particles 6 whose cross section is not a circle, the aspect ratio is obtained by setting the maximum length of the cross section as the short diameter. The conductive particles 6 do not necessarily have a straight shape, and can be used without any problems even if they are slightly bent or branched. In this case, the aspect ratio is obtained by setting the maximum length of the conductive particles 6 as the major axis.

According to the present embodiment described above, the following effects can be obtained.
(1) In the present embodiment, the main component is at least one thermosetting resin selected from an epoxy resin, a phenol resin, a polyurethane resin, an unsaturated polyester resin, and a urea resin, containing conductive particles, and The circuit connecting adhesive 2 containing a silane coupling agent having a mercapto group is used. Therefore, since the adhesive force between the thermosetting resin of the circuit connecting adhesive 2, the metal wiring electrode 4, and the protruding electrode 5 can be improved, the circuit connecting adhesive 2, the wiring electrode 4, and It is possible to prevent peeling of the wiring electrode 4 and the protruding electrode 5 at the bonding interface of the protruding electrode 5, and it is possible to prevent a decrease in moisture resistance and heat resistance of the thermosetting resin. Further, the connection reliability between the circuit board 1 and the electronic component 3 when the circuit board 1 and the electronic component 3 are connected via the circuit connecting adhesive 2 can be improved.

  (2) In this embodiment, the blending amount of the silane coupling agent having a mercapto group is 0.1 wt% or more and 5 wt% or less of the total weight of the thermosetting resin contained in the circuit connection adhesive 2. It is said. Therefore, it is possible to effectively exert a strong chemical bond between the surfaces of the wiring electrode 4 and the protruding electrode 5 and the coupling agent having a mercapto group. Further, it is possible to effectively prevent a decrease in moisture resistance and heat resistance of the thermosetting resin of the circuit connecting adhesive 2.

  (3) In the present embodiment, the silane coupling agent further includes a silane coupling agent having an epoxy group. Therefore, the resin component of the circuit connecting adhesive 2 and the circuit board 1 can be more firmly bound.

  (4) In this embodiment, the total amount of the silane coupling agent including the silane coupling agent having a mercapto group and the silane coupling agent having an epoxy group is included in the adhesive 2 for circuit connection. 0.1 wt% or more and 10 wt% or less of the total weight of the conductive resin. Therefore, even when the silane coupling agent contained in the circuit connecting adhesive 2 includes a silane coupling agent having an epoxy group in addition to the silane coupling agent having a mercapto group, the wiring electrode 4 and A strong chemical bond between the surface of the protruding electrode 5 and the coupling agent having a mercapto group can be effectively exhibited. Moreover, it becomes possible to prevent effectively the fall of the moisture resistance of the thermosetting resin of the circuit connection adhesive 2, and heat resistance.

  (5) In this embodiment, it is set as the structure in which the adhesive agent 2 for circuit connection contains the electroconductive particle 6 whose aspect-ratio is 5 or more. Accordingly, since the adhesive 2 for circuit connection contains the conductive particles 6 having a high contact probability, the wiring electrode 4 and the protruding electrode 5 can be conductively connected without increasing the blending amount of the conductive particles 6. Become.

  (6) In this embodiment, it is set as the structure which uses the adhesive agent 2 for circuit connection which has a film shape. Therefore, handling of the circuit connecting adhesive 2 is facilitated, and workability when the wiring electrode 4 and the protruding electrode 5 are connected by the circuit connecting adhesive 2 is improved.

  (7) In this embodiment, it is set as the structure which orientates the direction of the long diameter L of the electroconductive particle 6 in the thickness direction of the adhesive agent which has a film shape. Therefore, it is possible to electrically connect the plurality of wiring electrodes 4 to the protruding electrodes 5 at a time and independently, while maintaining insulation between adjacent electrodes and preventing a short circuit.

In addition, you may change the said embodiment as follows.
-It is good also as a structure using the short diameter R of the electroconductive particle 6 below 1 micrometer. By using such conductive particles 6, when an anisotropic conductive adhesive is used as the circuit connection adhesive 2, the contact probability between the conductive particles 6 is further increased. The wiring electrode 4 and the protruding electrode 5 can be conductively connected with the blending amount of the conductive particles 6.

  Below, this invention is demonstrated based on an Example and a comparative example. In addition, this invention is not limited to these Examples, These Examples can be changed and changed based on the meaning of this invention, and they are excluded from the scope of the present invention. is not.

Example 1
(Production of adhesive)
As the conductive particles, linear nickel fine particles having a long diameter L distribution of 1 μm to 8 μm and a short diameter R distribution of 0.1 μm to 0.4 μm were used. Examples of the resin include phenoxy resin [trade name Epicoat 1256 manufactured by Japan Epoxy Resin Co., Ltd.], liquid epoxy resin of bisphenol A [trade name Epicron 850 manufactured by Dainippon Ink and Chemicals Co., Ltd.], and naphthalene type epoxy resin. [Dainippon Ink Chemical Co., Ltd., trade name Epicron 4032D], mercapto group-containing silane coupling agent [Shin-Etsu Silicone Co., Ltd., trade name KBM803] and microcapsule type imidazole curing agent [Asahi Kasei Epoxy Corporation And trade name NOVACURE HX3941] in a weight ratio of 30/15/15/2/38.

  These resins and curing agent were dissolved in γ-butyrolactone and then kneaded with three rolls to prepare a solution having a resin concentration of 60% by weight. To this solution, the Ni powder was added so that the metal filling ratio represented by the ratio of the total solid content (Ni powder + resin) was 0.5% by volume, and then stirred using a centrifugal stirring mixer. As a result, Ni powder was uniformly dispersed to produce a composite material for an adhesive. Next, this composite material was applied onto a PET film subjected to a release treatment using a doctor knife, and then dried and solidified in a magnetic field with a magnetic flux density of 100 mT at 65 ° C. for 30 minutes, whereby linear particles in the film were obtained. An adhesive for circuit connection having an anisotropic conductivity in the form of a film having a thickness of 25 μm was prepared in the direction of the magnetic field.

(Resistance evaluation)
An IC chip in which 726 gold plated bumps having a width of 15 μm, a length of 100 μm, and a height of 16 μm are arranged at intervals of 15 μm, and 726 ITO electrodes having a width of 20 μm, a length of 100 μm, and a height of 0.3 μm are formed at intervals of 10 μm. A glass substrate was prepared. Then, the adhesive prepared between the IC chip and the glass substrate is sandwiched and heated to 180 ° C. for 30 seconds with a pressure of 20 gf per bump to be bonded to obtain a bonded body of the IC chip and the glass substrate. It was. Next, among the 726 electrodes of this joined body, the resistance value of 32 consecutive electrodes connected via the ITO electrode, the adhesive, and the gold bump is obtained by the four-terminal method, and the obtained value is 32. The connection resistance per electrode (hereinafter referred to as “initial connection resistance”) was obtained. And this evaluation was repeated 10 times and the average value of initial connection resistance was calculated | required. The results are shown in Table 1.

(Heat and humidity resistance evaluation)
In addition, as a heat and humidity resistance test, the joined body of the above IC chip and the glass substrate was left in a constant temperature and humidity chamber set at a temperature of 85 ° C. and a humidity of 85% for 200 hours, and then the bonded body was maintained at a constant temperature and humidity. It took out from the tank and calculated | required the average value of connection resistance again like the above. The results are shown in Table 1.

(Example 2)
Phenoxy resin [made by Japan Epoxy Resin Co., Ltd., trade name Epicoat 1256], bisphenol A type liquid epoxy resin [Dainippon Ink Chemical Co., Ltd., trade name Epicron 850], naphthalene type epoxy resin [Dainippon Ink] Chemical Industry Co., Ltd., trade name Epicron 4032D], mercapto group-containing silane coupling agent [Shin-Etsu Silicone Co., Ltd., trade name KBM803], and microcapsule type imidazole curing agent [Asahi Kasei Epoxy Co., Ltd., product An anisotropic conductive adhesive was prepared in the same manner as in Example 1 except that the weight ratio of NobaCure HX3941] was changed to 30/15/15/5/35, and an IC chip and a glass substrate were produced. A zygote was obtained. Thereafter, resistance evaluation and heat / moisture resistance evaluation were performed under the same conditions as in Example 1 above, and the above results are shown in Table 1.

(Example 3)
Phenoxy resin [made by Japan Epoxy Resin Co., Ltd., trade name Epicoat 1256], bisphenol A type liquid epoxy resin [Dainippon Ink Chemical Co., Ltd., trade name Epicron 850], naphthalene type epoxy resin [Dainippon Ink] Chemical Industry Co., Ltd., trade name Epicron 4032D], mercapto group-containing silane coupling agent [Shin-Etsu Silicone Co., Ltd., trade name KBM803], and microcapsule type imidazole curing agent [Asahi Kasei Epoxy Co., Ltd., product Nobacure HX3941], except that the weight ratio was changed to 30/15/15 / 0.2 / 39.8, and the anisotropic conductive adhesive was prepared in the same manner as in Example 1 above, and the IC A joined body of the chip and the glass substrate was obtained. Thereafter, resistance evaluation and heat / moisture resistance evaluation were performed under the same conditions as in Example 1 above, and the above results are shown in Table 1.

Example 4
As the resin, a phenoxy resin [manufactured by Japan Epoxy Resin Co., Ltd., trade name Epicoat 1256], a bisphenol A type liquid epoxy resin [Dainippon Ink Chemical Co., Ltd., trade name Epicron 850], a naphthalene type epoxy resin [ Dainippon Ink and Chemicals, trade name Epicron 4032D], mercapto group-containing silane coupling agent [Shin-Etsu Silicone Co., Ltd., trade name KBM803], epoxy group-containing silane coupling agent [Shin-Etsu Silicone Co., Ltd. , Trade name KBM403], and microcapsule type imidazole curing agent (trade name NovaCure HX3941 manufactured by Asahi Kasei Epoxy Co., Ltd.) in a weight ratio of 30/15/15/2/2/36 Is similar to Example 1 described above to produce an anisotropic conductive adhesive, To obtain a conjugate of C chips and the glass substrate. Thereafter, resistance evaluation and heat / moisture resistance evaluation were performed under the same conditions as in Example 1 above, and the above results are shown in Table 1.

(Comparative Example 1)
An anisotropic conductive adhesive was produced in the same manner as in Example 1 except that a mercapto group-containing silane coupling agent [trade name KBM803, manufactured by Shin-Etsu Silicone Co., Ltd.] was not used, and an IC chip. And the joined body of the glass substrate was obtained. Thereafter, resistance evaluation and heat / moisture resistance evaluation were performed under the same conditions as in Example 1 above, and the above results are shown in Table 1.

  As shown in Table 1, in any of Examples 1 to 4 and Comparative Example 1, there was almost no difference in the initial connection resistance. However, after leaving for 200 hours in a constant temperature and humidity chamber where the temperature is set to 85 ° C. and the humidity set to 85%, the connection resistance is smaller than in Comparative Example 1 in any of Examples 1 to 4. I understand that. This is because in Examples 1 to 4, since the silane coupling agent having a mercapto group is contained, the mercapto group of the silane coupling agent reacts with the surface of the wiring electrode and the protruding electrode, and the wiring electrode, In addition, a strong chemical bond occurs between the surface of the protruding electrode and the coupling agent, which is considered to be an improvement in the adhesive force between the resin component of the circuit connecting adhesive, the wiring electrode, and the protruding electrode. In particular, in Example 4, since the silane coupling agent having an epoxy group is further contained, it is considered that the resin component of the circuit connecting adhesive and the glass substrate are more firmly bound.

  As an application example of the present invention, the present invention relates to an adhesive for circuit connection for bonding and electrically connecting a substrate or an electronic component provided with electrodes, circuits and the like.

It is sectional drawing which shows the circuit board which mounted the electronic component with the adhesive agent for circuit connection which concerns on embodiment of this invention. As an adhesive for circuit connection according to an embodiment of the present invention, an anisotropic conductive adhesive containing conductive particles is used, and an electronic component is mounted on a circuit board via the anisotropic conductive adhesive. It is sectional drawing shown. It is a figure for demonstrating the electroconductive particle used in the adhesive agent for circuit connection which concerns on embodiment of this invention.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 ... Circuit board, 2 ... Circuit connection adhesive, 3 ... Electronic component, 4 ... Wiring electrode, 5 ... Projection electrode, 6 ... Conductive particle, X ... Thickness direction of the circuit connection adhesive which has a film shape, Y ... Surface direction of adhesive for circuit connection having film shape

Claims (7)

An adhesive for circuit connection comprising at least one thermosetting resin selected from an epoxy resin, a phenol resin, a polyurethane resin, an unsaturated polyester resin, and a urea resin as a main component, and containing conductive particles and a silane coupling agent In
The adhesive for circuit connection, wherein the silane coupling agent includes a silane coupling agent having a mercapto group.   The amount of the silane coupling agent having a mercapto group is 0.1 wt% or more and 5 wt% or less of the total weight of the thermosetting resin contained in the circuit connecting adhesive. The adhesive for circuit connection according to claim 1.   The adhesive for circuit connection according to claim 1, wherein the silane coupling agent further includes a silane coupling agent having an epoxy group.   The total weight of the thermosetting resin contained in the circuit connection adhesive is the total amount of the silane coupling agent including the mercapto group-containing silane coupling agent and the epoxy group-containing silane coupling agent. The adhesive for circuit connection according to claim 3, wherein the adhesive is 0.1 wt% or more and 10 wt% or less.   The adhesive for circuit connection according to any one of claims 1 to 4, wherein the conductive particles have an aspect ratio of 5 or more.   The adhesive for circuit connection according to any one of claims 1 to 5, wherein the adhesive has a film shape.   The adhesive for circuit connection according to claim 6, wherein a major axis direction of the conductive particles is oriented in a thickness direction of the adhesive having the film shape.

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