JP2014084395A - Electroconductive adhesive composition, electroconductive adhesive-fitted metal conductor wire, connection body, solar cell module, and method for manufacturing the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an electroconductive adhesive composition unaccompanied, even when left alone over an extended period after the electric connection of an electrode and a wire component, by the seepage of a thermosetting resin atop a solar cell and enabling electric junction at a low temperature; an electroconductive adhesive-fitted metal conductor wire, a connection body, and a solar cell module using the same; and a method for manufacturing the same.SOLUTION: The provided electroconductive adhesive composition comprises: (A) electroconductive particles including tin (Sn) and bismuth (Bi),;(B) a thermosetting resin solid at normal temperature (20°C) and having a softening point of 120°C or below; (C) a compound liquid at normal temperature (20°C) and possessing carbon-carbon double bonds; (D) a catalyst for accelerating the curing of the component (C); and (E) a flux activator.

Description

  The present invention relates to a conductive adhesive composition suitably used for electrical joining of a plurality of solar cells, a connection body, a solar cell module, and a method for manufacturing the same.

  As a means for solving the serious global warming and fossil energy depletion problems, solar cells, which are power generation systems using sunlight, are attracting attention. Current mainstream solar cells employ a structure in which solar cells in which electrodes are formed on a monocrystalline or polycrystalline Si wafer are connected in series or in parallel via wiring members. In general, for the connection between the electrode of the solar battery cell and the wiring member, a solder that exhibits good conductivity and is inexpensive has been used (Patent Document 1). Recently, in consideration of environmental problems, Sn-Ag-Cu solder that does not contain Pb is coated on a copper wire as a wiring member, and heated to a temperature higher than the melting temperature of the solder so that the electrode and wiring member of the solar battery cell are connected. A connection method is known (Patent Documents 1 and 2).

  Moreover, the use of a conductive adhesive that can be electrically connected at a low temperature has been proposed as an alternative material for solder (Patent Document 3). This conductive adhesive is a composition in which metal particles represented by silver particles are mixed and dispersed in a thermosetting resin, and these metal particles are in physical contact with the electrodes and wiring members of solar cells. Thus, an electrical connection is developed.

  In addition, as an alternative to solder, it contains thermosetting resin and metal particles and flux that melt at low temperatures, such as lead-free solder, and has a low melting temperature, good wettability, and high adhesive strength Has been proposed (Patent Document 4).

  These conductive adhesives are applied to the electrodes of the solar battery cell, and a wiring member is disposed thereon and heated, whereby the metal particles are fused to provide electrical connection between the electrode and the wiring member. Therefore, it is desired that the thermosetting resin is not completely cured until the metal particles are fused. This is because if the thermosetting resin is completely cured, the metals cannot be fused and the electrical characteristics may be affected. After obtaining the electrical connection between the electrode and the wiring member, it is desirable that a separate heating step is performed in the subsequent solar cell manufacturing process, and the thermosetting resin is cured at that time.

  On the other hand, in order to apply this conductive adhesive by a dispensing method or a printing method, it is necessary to be in a paste state at the time of application. In this case, in order to keep the paste state, a thermosetting resin is used at room temperature (20 ° C.). The liquid state is used.

  However, when a thermosetting resin in a liquid state at room temperature is used, if the thermosetting resin is left in a state where it is not completely cured for a long time, the thermosetting resin oozes out during this period, There exists a problem of spreading on a battery cell and contaminating a photovoltaic cell. If the thermosetting resin oozes out on the solar battery cell, the solar battery characteristics may be affected.

JP 2002-263880 A JP 2004-204256 A JP 2005-243935 A JP 2004-160508 A

  Therefore, the present invention provides a conductive material that does not bleed out the thermosetting resin on the solar cell and can be electrically connected at a low temperature even if the electrode and the wiring member are electrically connected and left for a long time. An object of the present invention is to provide a conductive adhesive composition and a metal wire with a conductive adhesive using the composition. Moreover, it aims at providing the connection body and solar cell module which used these conductive adhesive compositions or the metal conducting wire with conductive adhesive, and its manufacturing method.

The present invention relates to the following.
<1> (A) conductive particles containing tin (Sn) and bismuth (Bi), (B) a thermosetting resin that is solid at room temperature (20 ° C.) and has a softening point of 120 ° C. or less; (C) Conductivity containing a compound having a carbon-carbon double bond that is liquid at room temperature (20 ° C.), (D) a catalyst that promotes curing of component (C), and (E) a flux activator. Adhesive composition.
<2> The conductive adhesive composition, wherein the component (B) is an epoxy resin.
<3> The conductive adhesive composition, wherein the compound having a carbon-carbon double bond as the component (C) is a (meth) acrylic compound.
<4> The conductive adhesive composition, wherein the catalyst that accelerates the curing of the component (C) of the component (D) is a peroxide.
<5> Furthermore, the said conductive adhesive composition containing the catalyst which accelerates | stimulates hardening of (F) (B) component.
<6> The conductive adhesive composition, wherein the component (F) is an imidazole compound.
<7> The said conductive adhesive composition used in order to electrically connect the electrode of a photovoltaic cell, and a metal conducting wire.
<8> A connection body in which a plurality of solar cells are connected via metal conductors, wherein the electrodes of the solar cells and the metal conductors are connected via the conductive adhesive composition. body.
<9> A metal conductive wire with a conductive adhesive comprising a metal conductive wire and an adhesive layer covering the metal conductive wire, wherein the adhesive layer is bonded using the conductive adhesive composition. Metal conductor with conductive adhesive made of an agent.
<10> A connecting body comprising a plurality of solar cells and a metal wire with a conductive adhesive disposed on an electrode surface of the solar cells and electrically connecting the plurality of solar cells. The connection body, wherein the metal wire with conductive adhesive is the metal wire with conductive adhesive.
<11> A step of laminating a sealing material on both surfaces of the connection body, a glass on the sealing material on the light receiving surface side of the solar battery cell, and a protective film on the sealing material on the back surface of the solar battery cell And a step of sealing the solar cell while electrically connecting and bonding the solar cell and the metal conductor by heating the obtained laminate. Module manufacturing method.
<12> A solar battery module in which electrodes of a plurality of solar battery cells and metal conductors are electrically connected via the conductive adhesive composition.

  According to the present invention, even if the electrode and the wiring member are electrically connected and left standing for a long time, the thermosetting resin does not ooze out on the solar battery cell and can be electrically joined at a low temperature. A conductive adhesive composition and a metal wire with a conductive adhesive using the composition can be provided. Moreover, the connection body and solar cell module using these electrically conductive adhesive compositions or the metal conducting wire with an electrically conductive adhesive which have the said characteristic can be provided.

It is a schematic diagram which shows the principal part of the solar cell module which concerns on this invention. It is a figure for demonstrating one Embodiment of the manufacturing method of the solar cell module which concerns on this invention.

<Conductive adhesive composition>
The present invention is described in detail below.
The conductive adhesive composition of the present invention comprises (A) conductive particles containing tin (Sn) and bismuth (Bi), and (B) a solid at room temperature (20 ° C.), and a softening point of 120 ° C. or lower. A thermosetting resin, (C) a liquid compound having a carbon-carbon double bond at room temperature (20 ° C.), (D) a catalyst for promoting the curing of component (C), and (E) flux activity It is a conductive adhesive composition containing an agent.
By having such a configuration, the conductive adhesive composition does not ooze out and become contaminated with the thermosetting resin after the wiring members are connected, and can be electrically joined at a low temperature.
Each component will be described below.

<(A) Component: Conductive Particles Containing Tin (Sn) and Bismuth (Bi)>
The conductive adhesive composition of the present invention uses conductive particles containing (A) tin (Sn) and bismuth (Bi) (component (A)). The component (A) is not particularly limited as long as it contains tin (Sn) and bismuth (Bi) and contains conductive metal. The component (A) may contain a metal other than tin (Sn) and bismuth (Bi), but it is preferable to use a metal other than lead in consideration of environmental friendliness. For example, it may contain indium, zinc or the like. Thereby, melting | fusing point of electroconductive particle can be made low, maintaining favorable electroconductivity.

The melting point of the conductive particles (A) is preferably 210 ° C. or lower, more preferably 200 ° C. or lower, and still more preferably 180 ° C. or lower. Although the minimum of melting | fusing point of the electroconductive particle of (A) component is not specifically limited, It is about 100 degreeC. When such conductive particles are used in a conductive adhesive composition, the conductive particles melt and aggregate (fuse) at a relatively low temperature, and the aggregate contributes to the electrical connection of the object. Conceivable.
The melting point of the conductive particles can be measured by differential scanning calorimetry (DSC).

  Specifically, as the conductive particles of component (A), Sn42-Bi58 solder (melting point 138 ° C.), Sn42-Bi57-Ag1 solder (melting point 139 ° C.), Sn90-Ag2-Cu0.5-Bi7.5 solder (Melting point 189 ° C.), Sn89-Zn8-Bi3 solder (melting point 190 ° C.) and the like are preferable from the viewpoint of the solidification behavior of the conductive particles. The solidification behavior means that after the conductive particles are melted, they are cooled and solidified again. Among these, it is preferable to use Sn42-Bi58 solder or Sn42-Bi57-Ag1 solder from the viewpoint of availability and low melting point. These may be used alone or in combination of two or more.

  (A) Although the average particle diameter of electroconductive particle does not have a restriction | limiting in particular, It is preferable in it being 0.1-100 micrometers. When the average particle size is less than 0.1 μm, the viscosity of the conductive adhesive composition tends to be high and workability tends to be lowered. Moreover, when the average particle diameter of electroconductive particle exceeds 100 micrometers, it exists in the tendency for printability to fall and for connection reliability to fall. From the viewpoint of further improving the printability and workability of the conductive adhesive composition, the average particle size is more preferably 1.0 to 50 μm. Furthermore, from the viewpoint of further improving the storage stability of the conductive adhesive composition and the mounting reliability of the cured product, the average particle size is particularly preferably 5.0 to 30 μm. Here, an average particle diameter is the value calculated | required by the laser diffraction and the scattering method (Kamioka mining test method No. 2).

  (A) The conductive particles are composed only of metal, and the surface of particles made of a solid material other than metal such as ceramics, silica, and resin material is a metal having a melting point of 210 ° C. or less including tin and bismuth. The electroconductive particle coat | covered with the metal film which consists of may be sufficient, and those mixtures may be sufficient.

  The content of the conductive particles of the component (A) in the conductive adhesive composition is preferably 50 to 90% by mass with respect to the total amount of the conductive adhesive composition. If it is 50 mass% or more, electroconductive particle will fully aggregate. Moreover, if it is 90 mass% or less, it can suppress that the viscosity of a conductive adhesive composition becomes high, and can suppress the influence on printability. Furthermore, from the viewpoint of improving workability or conductivity, the content of the conductive particles of the component (A) is more preferably 60 to 85% by mass, and 65 to 65% from the viewpoint of improving the mounting reliability of the cured product. It is especially preferable that it is 80 mass%.

  In addition to the conductive particles of component (A), (a1) conductive particles made of a metal having a melting point higher than 210 ° C. may be used in combination. Examples of the metal having a melting point higher than 210 ° C. include, for example, one kind of metal selected from Pt, Au, Ag, Cu, Ni, Pd, Al and the like, or an alloy made of two or more kinds of metals. Specifically, Au powder, Ag powder, Cu powder, Ag plating Cu powder, etc. are mentioned. As a commercially available product, “MA05K” (trade name, manufactured by Hitachi Chemical Co., Ltd.), which is silver bronze powder, is available.

  When (A1) conductive particles made of a metal having a melting point higher than 210 ° C. are used in combination with the conductive particles of component (A), the mixing ratio is 99: 1 to (A) :( a1) in mass ratio. It is preferably within the range of 50:50, and more preferably within the range of 99: 1 to 60:40.

<(B) component: thermosetting resin which is solid at normal temperature (20 ° C.) and has a softening point of 120 ° C. or less>
The resin composition of the present invention contains a thermosetting resin (component (B)) that is solid at room temperature (20 ° C) of component (B) and has a softening point of 120 ° C or less. The component (B) has an action of adhering the adherend, and also acts as a binder component that bonds the conductive particles in the conductive adhesive composition and the filler added as necessary. The component (B) is a resin having a softening point of 120 ° C. or lower and a solid at room temperature. Since such a resin is softened at a temperature of 120 ° C. or lower during heating, it does not hinder the fusion of the conductive particles of the component (A). The normal temperature here is 20 ° C. By using such a resin, it is possible to prevent the resin from leaking out after being connected to the wiring member. When the softening point of (B) component exceeds 120 degreeC, it will become difficult to fuse | melt a particle | grain at the time of the melt | dissolution of the electroconductive particle of (A) component.

Although the softening point of (B) component is 120 degrees C or less, 20 degrees C or more and 110 degrees C or less are more preferable. It is more preferably 30 ° C. or higher and 100 ° C. or lower, and particularly preferably 35 ° C. or higher and 80 ° C. or lower.
Moreover, if the softening point of resin is 30 degreeC or more, it can suppress more that resin oozes out on a cell after connecting a wiring member, and is contaminated.

(B) component reacts with the below-mentioned (F) component added as needed, and it is preferable that the temperature which starts hardening is 80-150 degreeC, and it is more preferable that it is 100-150 degreeC, More preferably, it is 120-150 degreeC.
The temperature at which the (B) component and the (F) component react to start curing can be measured by differential scanning calorimetry (DSC).

  The component (B) is preferably an epoxy resin from the viewpoint of adhesion reliability. As the epoxy resin, a known compound can be used without particular limitation as long as it is a compound that has two or more epoxy groups in one molecule and is solid at room temperature. Such epoxy resins include, for example, bisphenol A, bisphenol AD, bisphenol S, bisphenol F or condensates of halogenated bisphenol A and epichlorohydrin, glycidyl ether of phenol novolac resin, glycidyl ether of cresol novolac resin, bisphenol A novolac resin. And glycidyl ether.

  As such an epoxy resin, a commercially available product can be used. Specific examples thereof include Epicoat 1004 (softening point 97 ° C.), 1004AF (softening point 97 ° C.), 1007 (softening point 128 ° C.), which are bisphenol A type epoxy resins (above, manufactured by Mitsubishi Chemical Corporation, trade name), YD-012 (softening point 75-85 ° C.), YD-013 (softening point 85-98 ° C.), YD-014 (softening point 91-102 ° C.) (Nippon Steel Chemical Co., Ltd., trade name), EPICLON 4050 (softening point 96-104 ° C.), EPICLON 7050 (softening point 122-131 ° C.) (manufactured by DIC Corporation, trade name), Epicoat 4005P (softening point 87 ° C.), which is a bisphenol F type epoxy resin, 4007P (Softening point 108 ° C) (Made by Mitsubishi Chemical Corporation, trade name), YDF-2005RL (softening point 91-96 ° C) (Nippon Steel Chemical Co., Ltd.) Company name, product name), Epicoat YX4000 (softening point 105 ° C.) which is a biphenyl type epoxy resin (trade name, manufactured by Mitsubishi Chemical Corporation), EPICLON 865 (softening point 64-72 ° C.) which is a modified novolak type epoxy resin ( DIC Corporation, trade name), EPICLON N-685-EXP-S (softening point 80-90 ° C.) which is a cresol novolac type epoxy resin (above, Mitsubishi Chemical Corporation, trade name), cresol novolak type epoxy resin Epototo YDCN-700-2 (softening point 57-64 ° C), YDCN-700-3, YDCN-700-5 (softening point 59-65 ° C), YDCN-700-7 (softening point 66-72 ° C) YDCN-700-10 (softening point 75-85 ° C.) (above, manufactured by Nippon Steel Chemical Co., Ltd., trade name), TECHMO E VG3101L (softening point 39-46 ℃) (Corporation pudding Tech, Ltd., trade name), JER 1032H60 (softening point 56-62 ℃) (Mitsubishi Chemical Co., Ltd., trade name), and the like. Among these epoxy resins, bisphenol A type epoxy resins, bisphenol F type epoxy resins, bisphenol AD type epoxy resins, and amine type epoxy resins that have few ionic impurities and are excellent in reactivity are particularly preferable. The above-mentioned epoxy resins are used singly or in combination of two or more.

  The content of the component (B) in the conductive adhesive composition is preferably 1 to 60% by mass, more preferably 5 to 40% by mass with respect to the total amount of the conductive adhesive composition. More preferably, it is -30 mass%.

<Component (C): Compound that is liquid at room temperature (20 ° C.) and has a carbon-carbon double bond>
The resin composition of the present invention contains (C) a compound (component (C)) that is liquid at room temperature (20 ° C.) and has a carbon-carbon double bond. The component (C) is not particularly limited as long as it is liquid at room temperature.
(C) As a component, it reacts with (D) component mentioned later, and it is preferable that the temperature which starts hardening is 80-200 degreeC, It is more preferable that it is 100-200 degreeC, 120-200 degreeC More preferably it is.
The temperature at which the (C) component and the (D) component react to start curing can be measured by differential scanning calorimetry (DSC). The component (C) is preferably cured at a temperature at which the component (A) melts.

A (meth) acryl compound is mentioned as an example of the compound which has a carbon-carbon double bond which hardens | cures at the temperature which electroconductive particle fuse | melts. (Meth) acrylic compounds refer to methacrylic compounds and acrylic compounds. Among these, a compound having a polymerizable carbon-carbon double bond in a molecule represented by a (meth) acrylic compound and a maleimide compound is preferable. Of these, the component (C) is preferably a (meth) acrylic compound. The (meth) acrylic compound begins to cure with a small heat capacity until the conductive particles of the component (A) are fused, and the resin does not leak out after electrically connecting the solar cell electrode and the wiring member. preferable.
Examples of (meth) acrylic compounds include monoacrylate compounds, monomethacrylate compounds, diacrylate compounds, and dimethacrylate compounds.

  Examples of the monoacrylate compound include methyl acrylate, ethyl acrylate, propyl acrylate, isopropyl acrylate, n-butyl acrylate, isobutyl acrylate, t-butyl acrylate, amyl acrylate, isoamyl acrylate, hexyl acrylate, heptyl acrylate, octyl acrylate, 2- Phenoxyethyl acrylate, 2-ethylhexyl acrylate, nonyl acrylate, decyl acrylate, isodecyl acrylate, lauryl acrylate, tridecyl acrylate, hexadecyl acrylate, stearyl acrylate, isostearyl acrylate, cyclohexyl acrylate, isobornyl acrylate, diethylene glycol acrylate, polyethylene glycol Coal acrylate, polypropylene glycol acrylate, 2-methoxyethyl acrylate, 2-ethoxyethyl acrylate, 2-butoxyethyl acrylate, methoxydiethylene glycol acrylate, methoxypolyethylene glycol acrylate, dicyclopentenyloxyethyl acrylate, phenoxydiethylene glycol acrylate, phenoxy polyethylene glycol acrylate, 2-benzoyloxyethyl acrylate, 2-hydroxy-3-phenoxypropyl acrylate, benzyl acrylate, 2-cyanoethyl acrylate, γ-acryloxyethyltrimethoxysilane, glycidyl acrylate, tetrahydrofurfuryl acrylate, dimethylaminoethyl acrylate, diethylamino Noethyl acrylate, acryloxyethyl phosphate, acryloxyethyl phenyl acid phosphate, and the like.

  Examples of the monomethacrylate compound include methyl methacrylate, ethyl methacrylate, propyl methacrylate, isopropyl methacrylate, n-butyl methacrylate, isobutyl methacrylate, t-butyl methacrylate, amyl methacrylate, isoamyl methacrylate, hexyl methacrylate, heptyl methacrylate, octyl methacrylate, 2- Ethylhexyl methacrylate, nonyl methacrylate, decyl methacrylate, isodecyl methacrylate, lauryl methacrylate, tridecyl methacrylate, hexadecyl methacrylate, stearyl methacrylate, isostearyl methacrylate, cyclohexyl methacrylate, isobornyl methacrylate, diethylene glycol methacrylate Polyethylene glycol methacrylate, polypropylene glycol methacrylate, 2-methoxyethyl methacrylate, 2-ethoxyethyl methacrylate, 2-butoxyethyl methacrylate, methoxydiethylene glycol methacrylate, methoxypolyethylene glycol methacrylate, dicyclopentenyloxyethyl methacrylate, 2-phenoxyethyl methacrylate, phenoxydiethylene glycol Methacrylate, phenoxypolyethylene glycol methacrylate, 2-benzoyloxyethyl methacrylate, 2-hydroxy-3-phenoxypropyl methacrylate, benzyl methacrylate, 2-cyanoethyl methacrylate, γ-methacryloxyethyltrimethoxysilane, glycidyl methacrylate , Tetrahydrofurfuryl methacrylate, dimethylaminoethyl methacrylate, diethylaminoethyl methacrylate, methacryloxyethyl phosphate, methacryloxyethyl phenyl acid phosphate, and the like.

  Examples of the diacrylate compound include ethylene glycol diacrylate, 1,4-butanediol diacrylate, 1,6-hexanediol diacrylate, 1,9-nonanediol diacrylate, 1,3-butanediol diacrylate, neo Pentyl glycol diacrylate, diethylene glycol diacrylate, triethylene glycol diacrylate, tetraethylene glycol diacrylate, polyethylene glycol diacrylate, tripropylene glycol diacrylate, polypropylene glycol diacrylate, bisphenol A, bisphenol F or bisphenol AD 1 mole and glycidyl acrylate 2 Mole reactant, polyethylene of bisphenol A, bisphenol F or bisphenol AD Examples include diacrylates of oxide adducts, diacrylates of polypropylene oxide adducts of bisphenol A, bisphenol F or bisphenol AD, bis (acryloxypropyl) polydimethylsiloxane, and bis (acryloxypropyl) methylsiloxane-dimethylsiloxane copolymers. .

Examples of the dimethacrylate compound include ethylene glycol dimethacrylate, 1,4-butanediol dimethacrylate, 1,6-hexanediol dimethacrylate, 1,9-nonanediol dimethacrylate, 1,3-butanediol dimethacrylate, neodymium. Pentyl glycol dimethacrylate, diethylene glycol dimethacrylate, triethylene glycol dimethacrylate, tetraethylene glycol dimethacrylate, polyethylene glycol dimethacrylate, tripropylene glycol dimethacrylate, polypropylene glycol dimethacrylate, bisphenol A, bisphenol F or bisphenol AD 1 mole and glycidyl methacrylate 2 Molar reactants, bisphenol A, bisphenol F or bi Dimethacrylate of a polyethylene oxide adduct of phenol AD, polypropylene oxide adduct of bisphenol F or bisphenol AD, bis (methacryloxypropyl) polydimethylsiloxane, and bis (methacryloxypropyl) methylsiloxane - include dimethylsiloxane copolymers.
These compounds are used alone or in combination of two or more.

  The content of the compound having a carbon-carbon double bond as the component (C) in the conductive adhesive composition is preferably 1 to 60% by mass with respect to the total amount of the conductive adhesive composition, More preferably, it is 40 mass%, and it is further more preferable that it is 10-30 mass%.

  Moreover, the conductive adhesive composition of this invention uses (B) component and (C) component together. From the viewpoint of the viscosity of the adhesive, the content ratio of the component (B) and the component (C) in the conductive adhesive composition is (B) :( C) = 30: 70 to 99: 1. It is preferably 40:60 to 90:10, more preferably 50:50 to 80:20.

<(D) component: catalyst which accelerates | stimulates hardening of (C) component>
The resin composition of this invention contains the catalyst ((D) component) which accelerates | stimulates hardening of (C) component as (D) component. Although there is no restriction | limiting in particular as (D) component, Since a thermosetting resin is comprised from the compound which has a carbon-carbon double bond which can superpose | polymerize, a conductive adhesive composition is generally known as a radical polymerization initiator. What is provided is preferable. The radical polymerization initiator is more preferably a peroxide from the viewpoint of effectively suppressing voids. Moreover, from the viewpoint of improving the curability and viscosity stability of the conductive adhesive composition, the organic peroxide preferably has a decomposition temperature of 70 to 170 ° C, more preferably 80 to 160 ° C. preferable.

  Examples of the component (D) include 1,1,3,3-tetramethylbutylperoxy 2-ethylhexanoate, 1,1-bis (t-butylperoxy) cyclohexane, 1,1-bis (t -Butylperoxy) cyclododecane, di-t-butylperoxyisophthalate, t-butylperoxybenzoate, dicumyl peroxide, t-butylcumyl peroxide, 2,5-dimethyl-2,5-di (t -Butylperoxy) hexane, 2,5-dimethyl-2,5-di (t-butylperoxy) 3-hexyne, cumene hydroperoxide and the like. These are used singly or in combination of two or more.

  The content of the component (D) is preferably 0.01 to 20% by mass, more preferably 0.05 to 10% by mass, and more preferably 0.1 to 5% with respect to the total amount of the conductive adhesive composition. More preferably, it is mass%.

  Moreover, the conductive adhesive composition of this invention uses (C) component and (D) component together. The content ratio of the component (C) and the component (D) in the conductive adhesive composition is a mass ratio from the viewpoint of reaction rate, and (C) :( D) = 100: 0.1 to 100: 20. It is preferable that it is 100: 0.5-100: 15, and it is more preferable that it is 100: 1.0-100: 10.

<(E) component: flux activator>
The resin composition of the present invention contains a flux activator ((E) component) as the (E) component. The (E) component flux activator exhibits the ability to remove the oxide film formed on the surface of the conductive particle (A). By using such a flux activator, the oxide film that hinders aggregation of the conductive particles of the component (A) is removed. As the flux activator of the component (E), a known compound can be used without particular limitation as long as it does not inhibit the curing reaction of the component (B) and the component (C). Examples of such compounds include rosin resins, compounds containing a carboxyl group, phenolic hydroxyl group or alcoholic hydroxyl group in the molecule, adipic acid, 2,4-diethylglutaric acid, 2,2-diethylglutaric acid, 3- Dibasic acids having an alkyl group in the side chain such as methylglutaric acid, 2-ethyl-3-propylglutaric acid, 2,5-diethyladipic acid, and the like are listed, but they exhibit good flux activity and (B) component In view of good reactivity with the epoxy resin used as the thermosetting resin, a compound containing a hydroxyl group and a carboxyl group in the molecule is preferable, and aliphatic dihydroxycarboxylic acid is particularly preferable. Specifically, a compound represented by the following general formula (I) or tartaric acid is preferable.

ここで、一般式（Ｉ）中、Ｒ^５は炭素数１〜５のアルキル基を示し、一般式（Ｉ）で表される化合物を用いることによる効果をより有効に発揮する観点から、メチル基、エチル基又はプロピル基であると好ましい。また、ｎ及びｍはそれぞれ独立に０〜５の整数を示し、一般式（Ｉ）で表される化合物を用いることによる効果をより有効に発揮する観点から、ｎが０かつｍが１であるか、ｎ及びｍの両方が１であると好ましく、ｎ及びｍの両方が１であるとより好ましい。

Here, in the general formula (I), from the viewpoint R ⁵ is that effective by the use of an alkyl group having 1 to 5 carbon atoms, the compound represented by the general formula (I) more effectively, a methyl group , Ethyl group or propyl group is preferable. N and m each independently represents an integer of 0 to 5, and n is 0 and m is 1 from the viewpoint of more effectively exerting the effect of using the compound represented by the general formula (I). Or n and m are both preferably 1, and both n and m are more preferably 1.

  Examples of the compound represented by the general formula (I) include 2,2-bis (hydroxymethyl) propionic acid, 2,2-bis (hydroxymethyl) butanoic acid, and 2,2-bis (hydroxymethyl) pentane. Examples include acids.

  The content of the flux activator of the component (E) is 0.1 to 30 masses with respect to 100 mass parts of the total amount of the conductive particles of the component (A), from the viewpoint of more effectively exhibiting the above effect according to the present invention. Part. Furthermore, from a storage stability and an electroconductive viewpoint, it is more preferable that it is 0.5-20 mass parts, and it is further more preferable that it is 1-10 mass parts.

  (E) If the content of the flux activator is 0.1 parts by mass or more, the meltability of the conductive particles of the component (A) is sufficient, and if it is 30 parts by mass or less, the conductive adhesive composition is stored. There exists a tendency for stability and applicability to become better.

<(F) component: catalyst which accelerates | stimulates hardening of (B) component>
The conductive adhesive composition of the present invention may contain a catalyst (component (F)) that accelerates curing of the component (B) as the component (F) as necessary. The component (F) may be any component that accelerates the curing of the component (B), and it is preferable to use what is called a curing agent or a curing accelerator.

  As a hardening | curing agent, if it is conventionally used, it will not specifically limit, A commercially available thing is available. Commercially available curing agents include, for example, phenol novolak resin H-1 (trade name, manufactured by Meiwa Kasei Co., Ltd.), VR-9300 (trade name, manufactured by Mitsui Chemicals), and XL-225, which is a phenol aralkyl resin. (Trade name) manufactured by Mitsui Chemicals, Inc., MTPC (trade name, manufactured by Honshu Chemical Industry Co., Ltd.) which is a p-cresol novolak resin represented by the following general formula (II), and AL- which is an allylated phenol novolak resin Examples include VR-9300 (trade name, manufactured by Mitsui Chemicals, Inc.), PP-700-300 (trade name, manufactured by Nippon Petrochemical Co., Ltd.), which is a special phenol resin represented by the following general formula (III).

（一般式（ＩＩ）中、Ｒ^１は、それぞれ独立に１価の炭化水素基、好ましくはメチル基又はアリル基を示し、ｑは１〜５の整数を示す。また、一般式（ＩＩＩ）中、Ｒ^２はアルキル基、好ましくはメチル基又はエチル基を示し、Ｒ^３は水素原子又は１価の炭化水素基を示し、ｐは２〜４の整数を示す。）

(In General Formula (II), each R ¹ independently represents a monovalent hydrocarbon group, preferably a methyl group or an allyl group, and q represents an integer of 1 to 5. In addition, in General Formula (III) R ² represents an alkyl group, preferably a methyl group or an ethyl group, R ³ represents a hydrogen atom or a monovalent hydrocarbon group, and p represents an integer of 2 to 4.)

  When the curing agent is contained, the content ratio of the component (B) and the component (F) is a mass ratio from the viewpoint of adhesive force and reaction rate, and (B) :( F) = 100: 0.1-100. : 20, more preferably 100: 0.5 to 100: 15, and still more preferably 100: 1.0 to 100: 10.

  When the curing agent is contained and the component (B) is an epoxy resin, the content of the curing agent is the total amount of reactive groups in the curing agent with respect to 1.0 equivalent of the epoxy group of the epoxy resin. The ratio is preferably 0.2 to 1.2 equivalent, more preferably 0.4 to 1.0 equivalent, and 0.5 to 1.0 equivalent. Further preferred. When the reactive group is 0.2 equivalent or more, the reflow crack resistance of the adhesive component becomes better, and when it is 1.2 or less, the viscosity of the adhesive component becomes moderate and the workability tends to be better. There is. The reactive group is a substituent having a reactive activity with an epoxy resin, and examples thereof include a phenolic hydroxyl group.

  Moreover, as a hardening accelerator, if it is conventionally used as a hardening accelerator, such as dicyandiamide, it will not specifically limit, A commercial item is available. Examples of commercially available products include ADH, PDH, and SDH (trade names, manufactured by Nippon Hydrazine Kogyo Co., Ltd.), which are dibasic acid dihydrazides represented by the following general formula (IV), and reaction between an epoxy resin and an amine compound. NOBACURE (trade name, manufactured by Asahi Kasei Kogyo Co., Ltd.), which is a microcapsule type curing agent made of a product. These curing accelerators are used alone or in combination of two or more.

一般式（ＩＶ）中、Ｒ^４は２価の芳香族基又は炭素数１〜１２の直鎖若しくは分岐鎖のアルキレン基を示し、好ましくはｍ−フェニレン基又はｐ−フェニレン基を示す。

In the general formula (IV), R ⁴ represents a divalent aromatic group or a linear or branched alkylene group having 1 to 12 carbon atoms, preferably an m-phenylene group or a p-phenylene group.

  When the curing accelerator is contained, the content ratio of the component (B) and the component (F) is a mass ratio from the viewpoint of adhesive force and reaction rate, and (B) :( F) = 100: 0.01 to The ratio is preferably 100: 50, more preferably 100: 0.1 to 100: 30, and still more preferably 100: 0.5 to 100: 20.

  When the curing agent is contained and the component (B) is an epoxy resin, the content of the component (F) is preferably 0.01 to 90 parts by mass with respect to 100 parts by mass of the epoxy resin. More preferably, it is 1 to 50 parts by mass. When the blending ratio of this curing accelerator is 0.01 parts by mass or more, the curability becomes better, and when it is 90 parts by mass or less, the viscosity becomes appropriate and the workability becomes better.

Further, as commercially available curing accelerators, in addition to or in place of the above, for example, EMZ · K, TPPK (trade name, manufactured by Hokuko Chemical Co., Ltd.), tertiary amine, which are organic boron salt compounds, are used. DBU, U-CAT102, 106, 830, 840 and 5002 (trade name, manufactured by San Apro Co., Ltd.), azoles such as Cureazole, 2PZ-CN, 2P4MHZ-PW, C17Z, 2PZ-OK 2PZ-CNS and C11Z-CNS (above, Shikoku Kasei Kogyo Co., Ltd., trade name) may be used.
The mixing ratio of these curing accelerators is preferably 0.1 parts by mass or more and 20 parts by mass or less with respect to 100 parts by mass of the component (B). Furthermore, it is preferable in it being 15 mass parts or less.
Moreover, you may use a hardening | curing agent and a hardening accelerator individually by 1 type or in combination of 2 or more types, respectively.

<Other ingredients>
In addition to the above-mentioned thermosetting resin, one or more thermoplastic resins that function as a binder may be added to the conductive adhesive composition of the present invention. Examples of the thermoplastic resin include ABS resin (acrylonitrile, butadiene, styrene copolymer synthetic resin), polypropylene resin, polyethylene resin, polyvinyl chloride resin, polystyrene resin, polymethyl methacrylate resin, polybutadiene resin, polyethylene terephthalate resin, polyphenylene. Ether resin, nylon resin, polyamide resin, polycarbonate resin, polyacetal resin, polybutylene terephthalate resin, polyphenylene sulfide resin, polyether ether ketone resin, modified polyphenylene ether resin, liquid crystal polymer, fluorine resin, urethane resin, polyarylate resin, polyimide Examples thereof include resins, polyamideimide resins, polyetherimide resins, polyethersulfone resins, and polysulfone resins. These thermoplastic resins are used alone or in combination of two or more.

  In addition, the conductive adhesive composition may contain a coupling agent such as a silane coupling agent or a titanium coupling agent for the purpose of improving the adhesive strength. Examples of the silane coupling agent include trade name “KBM-573, N-phenyl-3-aminopropyltrimethoxysilane” manufactured by Shin-Etsu Chemical Co., Ltd. Further, for the purpose of improving wettability, an anionic surfactant or a fluorosurfactant may be contained in the adhesive component. Furthermore, you may contain silicone oil etc. as an antifoamer. The said adhesive force improver, wettability improver, and antifoamer are used individually by 1 type or in combination of 2 or more types, respectively. It is preferable that 0.1-10 mass% of content for containing a coupling agent is contained with respect to whole quantity of a conductive adhesive composition.

  The conductive adhesive composition may contain a filler. Examples of the filler include polymer particles such as acrylic rubber and polystyrene, and inorganic particles such as diamond, boron nitride, aluminum nitride, alumina, and silica. These fillers may be used alone or in combination of two or more.

  In addition to the above-described components, the conductive adhesive composition includes, as necessary, a flexible agent for stress relaxation, a diluent for improving workability, an adhesive strength improver, a wettability improver, and an antifoaming agent. One or more additives selected from the group consisting of agents may be included. In addition to these components, various additives may be included within a range that does not impair the effects of the present invention.

  For example, as a flexible agent, CTBN-1300x31, CTBN-1300x9 (above, Ube Industries, Ltd., brand name), NISSO-PB-C-2000 (Nippon Soda Co., Ltd., brand name) etc. Liquid polybutadiene. When it contains a flexible agent, the content is suitably 0.01 to 500 parts by mass with respect to 100 parts by mass of the total amount of the thermosetting resin.

  An organic solvent can be added to the conductive adhesive composition as necessary in order to improve the workability during preparation of the paste composition and the application workability during use. As such an organic solvent, an organic solvent having a relatively high boiling point such as butyl cellosolve, carbitol, butyl cellosolve, carbitol acetate, dipropylene glycol monomethyl ether, ethylene glycol diethyl ether, and α-terpineol is preferable. It is preferable that 0.1-30 mass% of content in the case of containing this organic solvent is contained with respect to the whole quantity of a conductive adhesive composition.

  In the present invention, the components described above may be combined with any of those exemplified above.

  Since the conductive adhesive composition of the present invention contains the components (C) and (D), it is generally a liquid conductive adhesive composition.

<Method for adjusting conductive adhesive composition>
In the above-mentioned conductive adhesive composition, each component described above is divided into one or more times and heated as necessary, and each component is uniformly dispersed by mixing, dissolving, pulverizing kneading or dispersing. Obtained as a paste. Examples of the dispersing / dissolving device used in this case include a known stirrer, a leaker, a three roll, a planetary mixer and the like.

According to the conductive adhesive composition according to the present embodiment described above, the conductive adhesive composition that does not bleed out of the resin after connecting the metal wiring member and can be electrically joined at a low temperature. Can be provided. In addition, a highly reliable solar cell module can be obtained by using a conductive adhesive composition or a metal wire with a conductive adhesive that can be bonded at a low temperature and has no leakage of resin after connecting metal wiring members. Can be provided.
In other words, the conductive adhesive composition of the present invention is preferably used for electrically connecting the electrode of the solar battery cell and the metal conductor.

<Connector, metal conductor and solar cell module>
The connection body of the present invention is a connection body in which a plurality of solar battery cells are connected via a metal conductor, and the electrode of the solar battery cell and the metal conductor are connected via the conductive adhesive composition. Connected body.
Further, the metal conductor of the present invention is a metal conductor with a conductive adhesive comprising a metal conductor and an adhesive layer covering the metal conductor, wherein the adhesive layer is the conductive adhesive. It is a metal wire with a conductive adhesive comprising an adhesive using the composition. If this metal conducting wire is used, the process of apply | coating a conductive adhesive to the electrode or wiring member of a photovoltaic cell can be omitted.
Furthermore, the connection body of the present invention includes a plurality of solar cells and a metal conductor with a conductive adhesive disposed on the electrode surface of the solar cells and electrically connecting the plurality of solar cells. The connection body is a connection body in which the metal wire with conductive adhesive is the metal wire with conductive adhesive.

  The manufacturing method of the solar cell module of the present invention includes a step of laminating a sealing material on both surfaces of the connection body, a glass on the sealing material on a light receiving surface side of the solar cell, and a back surface of the solar cell. The step of laminating a protective film on the encapsulant, and the solar cell is sealed while electrically connecting and bonding the solar cell and the metal conductor by heating the obtained laminate And a process for manufacturing a solar cell module. Moreover, the solar cell module of the present invention is a solar cell module in which electrodes of a plurality of solar cells and metal conductors are electrically connected via the conductive adhesive composition.

  Next, an example of a solar cell module manufactured using the conductive adhesive composition of the present embodiment will be described with reference to FIG.

  FIG. 1 is a schematic diagram showing a main part of a solar cell module, and shows an outline of a structure in which a plurality of solar cells are interconnected as an example. Fig.1 (a) shows the surface side of a solar cell module, FIG.1 (b) shows a back surface side, FIG.1 (c) shows a side surface side.

  As shown in FIGS. 1A to 1C, the solar cell module 100 includes a grid electrode 7 and a bus bar electrode (front electrode) 3a on the front side of the semiconductor wafer 6, and a back electrode 8 and a bus bar electrode (on the back side). A plurality of solar cells 20 each having a surface electrode 3 b are connected to each other by a wiring member 4. The wiring member 4 is electrically connected to the bus bar electrode 3a serving as a surface electrode at one end and the bus bar electrode 3b serving as a surface electrode through the conductive adhesive composition 10 of the present embodiment. Has been. The conductive adhesive composition of the present embodiment is applied to either or both of the electrode on the solar cell side cell surface and the wiring member using a non-contact type dispenser.

  FIG. 2 is a diagram for explaining one embodiment of a method for producing a solar cell module of the present embodiment.

  The solar cell module of the present embodiment is, for example, a step of applying the conductive adhesive composition 10 of the present embodiment on the bus bar electrodes 3a and 3b by a non-contact dispenser, and applying the conductive adhesive composition 10 on the bus bar electrodes 3a and 3b. The wiring member 4 is disposed on the conductive adhesive composition 10 thus prepared, the step of producing the connection body 30, the step of disposing the sealing material 2 on both surfaces of the connection body 30, and the light receiving surface of the solar battery cell 20. The glass 1 is placed on the sealing material 2 on the side, the back sheet 5 (protective film) is placed on the sealing material 2 on the back surface of the solar battery cell 20, and the resulting laminate is 1 at a temperature of 140 to 210 ° C. It is manufactured by a manufacturing method including a step of thermocompression bonding at a pressure of 0.1 to 6 MPa for ˜30 minutes. In this thermocompression bonding step, electrical connection between the bus bar electrodes 3a and 3b of the solar battery cell 20 and the wiring member 4 and adhesion by curing of the thermosetting resin are performed. Sealing is performed, and a solar cell module can be manufactured in a lump.

  In addition to these manufacturing methods, after arranging the wiring member 4 and the bus bar electrodes 3a and 3b to face each other through the conductive adhesive composition 10, the temperature is 140 to 210 ° C. for 1 to 30 minutes, Temporary pressure bonding may be performed in which the bus bar electrodes 3a and 3b and the wiring member 4 are electrically connected by heat pressure bonding at a pressure of 0.1 to 6.0 MPa. Since the solar battery cells and the wiring member 4 are connected by performing the temporary pressure bonding, the connection body 30 becomes easy to handle, and workability at the time of manufacturing the solar battery module is improved.

  When temporary pressure bonding is performed, the sealing material 2 is disposed on both surfaces of the obtained connection body 30, the glass 1 is placed on the sealing material 2 on the light receiving surface side of the solar battery cell 20, and the back surface of the solar battery cell 20 is A back sheet 5 (protective film) is placed on the sealing material 2, and the obtained laminate is thermocompression bonded at a temperature of 140 to 180 ° C. for 1 to 30 minutes at a pressure of 0.1 to 6 MPa. A solar cell module can be manufactured by sealing.

  Examples of the glass 1 include white plate-reinforced glass with dimples for solar cells. Examples of the sealing material 2 include sealing resins using ethylene / vinyl acetate copolymer resin (EVA) or polyvinyl butyral. Examples of the wiring member 4 include a TAB wire obtained by dipping or plating a solder on a Cu wire. Examples of the back sheet 5 include PET (polyethylene terephthalate resin) -based or Tedlar (polyvinyl fluoride resin) -PET laminated material, metal foil-PET laminated material, and the like.

  The conductive adhesive composition of the present embodiment can be connected to the electrodes of the solar battery cells in the above-described process even when using a wiring board in which a metal lead is formed on a plastic substrate. Moreover, also when using a film-form wiring board, it can connect with the electrode of a photovoltaic cell by the process similar to the above using the conductive adhesive composition of this embodiment.

  The cured product of the conductive adhesive composition of the present embodiment can be used as a substrate, an electronic component, and a conductive layer that bonds and electrically connects the substrate and the electronic component. Further, it can also be used as a support layer for mounting a semiconductor, a semiconductor element, and a conductive layer that bonds and electrically connects the support base and the semiconductor element.

  Moreover, the conductive adhesive composition of the present embodiment can also be used for connection between the electrode of the back electrode type (back contact type) solar battery cell and the wiring member. In this case, first, the conductive adhesive composition of the present embodiment is applied onto the electrode of the wiring board or the back electrode of the solar battery cell. Next, a sealing material formed by hollowing out the electrode part (conductive adhesive composition application part) of the wiring board is laminated on the wiring board, and the solar battery cell is placed on the sealing material, and the back electrode of the solar battery cell and the electrode of the wiring board. It arrange | positions so that a part may contact | connect via a conductive adhesive composition. Further, a sealing material and glass are disposed on the light receiving surface of the solar battery cell, a back sheet is disposed on the back surface side of the solar battery cell, and the solar battery module is thermocompression-bonded, whereby the back electrode of the solar battery cell and the wiring board The connection and adhesion with the electrodes, and the sealing step of the solar battery cell can be performed at once. As the glass and the sealing material, those mentioned in the method for producing the solar cell module can be used.

  EXAMPLES Hereinafter, although an Example demonstrates this invention further in detail, this invention is not limited to these Examples. In addition, the material used by the Example and the comparative example was produced by the following method, or was obtained. An example of the preparation method is shown in Example 1, but the resin compositions and blending ratios of other Examples and Comparative Examples are as shown in Table 1, and the preparation method is the same as Example 1.

[Example 1]
(B) YDCN-700-10 (a novolac epoxy resin, solid at room temperature, softening point 75-85 ° C.) as component [a thermosetting resin that is solid at room temperature (20 ° C.) and has a softening point of 120 ° C. or lower] , Manufactured by Nippon Steel Chemical Co., Ltd., trade name: 12.5% by mass, 2F4MHZ-PW (2-phenyl-4-methyl-5-hydroxy) as component (F) [a catalyst for promoting curing of component (B)] SR339A (2-phenoxyethyl) as methyl imidazole, manufactured by Shikoku Kasei Kogyo Co., Ltd., 0.4% by mass, and component (C) [normal temperature (20 ° C.) liquid and carbon-carbon double bond compound] Acrylate, liquid at normal temperature, manufactured by Sakai Kogyo Co., Ltd., trade name) 9.8% by mass, and Trigonox 22-70E (1,1-di-) as component (D) [a catalyst for promoting curing of component (C)] t-Buchi Peroxycyclohexane, manufactured by Kayaku Akzo Co., Ltd., trade name) 0.3% by mass, and ADAc (adipic acid, manufactured by Asahi Kasei Chemicals Co., Ltd.) 2.0% by mass as component (E) [flux activator] The adhesive component was prepared by passing three rolls three times.
Next, 75% by mass of Sn42-Bi58 particles (average particle diameter 20 μm, melting point: 138 ° C.), which are conductive particles, was added to and mixed with 25% by mass of the adhesive component described above. Furthermore, after passing 3 rolls 3 times through those mixtures, the electrically conductive adhesive composition was obtained by performing a defoaming process for 10 minutes at 500 Pa or less using a vacuum stirrer.

[Examples 2 to 6 and Comparative Examples 1 to 4]
Except having set it as the composition shown in Table 1, it carried out similarly to Example 1, and obtained the conductive adhesive composition of Examples 2-6 and Comparative Examples 1-4. The details of the materials shown in Table 1 are as follows. Moreover, the unit of the blending ratio of each material in Table 1 is mass%.

1032H60 (polyfunctional epoxy resin (triphenylmethane type epoxy resin), solid at normal temperature, softening point 56-62 ° C., trade name, manufactured by Mitsubishi Chemical Corporation)
TECHMORE VG3101L (trifunctional epoxy resin (triglycidyl isocyanurate epoxy resin), solid at room temperature, softening point 39-46 ° C., trade name, manufactured by Printec Co., Ltd.)
YL983-U (bisphenol F type epoxy resin, liquid at room temperature, manufactured by Mitsubishi Chemical Corporation, trade name) resin that is liquid at room temperature,
KAYARAD R712 (acrylic resin (acrylic compound, 2,2′-methylenebis [p-phenylenepoly (oxyethylene) oxy] diethyldiacrylate), liquid at room temperature, Nippon Kayaku Co., Ltd., trade name),
Park mill D (polymerization initiator (dicumyl peroxide), manufactured by NOF Corporation, trade name)
・ BHPA (2,2-bis (hydroxymethyl) propionic acid, manufactured by Tokyo Chemical Industry Co., Ltd., trade name)

  The characteristics of the conductive adhesive compositions according to Examples 1 to 6 and Comparative Examples 1 to 4 were measured by the following method. The results are summarized in Table 1.

[Evaluation of stability]
When the conductive adhesive compositions obtained in Examples 1 to 6 and Comparative Examples 1 to 4 were observed after standing for 24 hours at 25 ° C., the state where there was no visual abnormality such as sedimentation / separation was visually indicated as “A ”And a slight separation and sedimentation is confirmed on the appearance, but“ B ”is a state that becomes uniform by weak stirring with a chemical spoon, etc. Evaluated as “C”.

[Evaluation of cohesiveness]
A surface electrode (material: silver glass) formed on the light-receiving surface of the solar cell (125 mm × 125 mm, thickness 310 μm) using the conductive adhesive compositions obtained in Examples 1 to 6 and Comparative Examples 1 to 4 A paste cell, 2 mm × 125 mm) was printed using a metal mask (thickness 100 μm, opening size 0.2 mm × 125 mm) to prepare a coating cell.
After heating at 160 ° C. for 10 seconds on a hot plate, the state of metal aggregation in the conductive particles was confirmed with an X-ray fluoroscope (Microfocus X-ray fluoroscope SMX-1000 manufactured by Shimadzu Corporation). evaluated. In addition, if aggregation of a metal is observed, it can be said that the electrode of a photovoltaic cell and the wiring member are electrically connected.
"A": Completely aggregated, no unaggregated particles "B": Agglomerated but some unaggregated particles "C": Not aggregated at all "-": Cannot be applied and cannot be measured

[Evaluation of resin seepage]
The conductive adhesive compositions obtained in Examples 1 to 6 and Comparative Examples 1 to 4 were coated with a metal mask (thickness 150 μm, opening size 0.1 mm) on the light receiving surface of the solar battery cell (manufactured by Taku Material Co., Ltd.). × 125 mm) was used to produce a coating cell. After heating at 160 ° C. for 5 seconds on a hot plate, the initial spread width of the resin was observed. Thereafter, the spread width of the resin was observed again after standing at 25 ° C. for 48 hours.
Evaluated as “A” when the difference between the initial spread width and the spread width after standing is less than 1 mm, “B” when the spread width after standing is 1 mm or more and less than 3 mm, and “C” when 3 mm or more. did.

  It can be confirmed that the conductive adhesive compositions of Examples 1 to 6 are heated and melted at 160 ° C. so that the conductive particles melt and agglomerate, and the resin does not exude after a lapse of time. It was. At 160 ° C., the epoxy resin that is solid at room temperature also becomes liquid beyond the softening point, so that the metal can be melted. On the other hand, SR339A, which is liquid at room temperature, was cured at 160 ° C. for 5 seconds after melting the metal, and the other components were solid, so it is considered that the resin did not exude.

  On the other hand, when YL983U that is liquid at room temperature is used as the thermosetting resin of component (B) in Comparative Example 1, the stability and the cohesiveness of the metal are the same as those in Examples 1 to 6, but after a lapse of time. The resin seepage is large. This result is considered that YL983U, which is liquid at room temperature, did not cure at 160 ° C. for 5 seconds at the time of metal bonding and remained in a liquid state, so that it spread over the cell with time.

  In Comparative Example 2, the peroxide of component (D), which is a catalyst (polymerization initiator) that accelerates curing of the compound (C) that is liquid at room temperature (20 ° C.) and has a carbon-carbon double bond, Not contained, the stability and cohesiveness of the paste is the same as in Examples 1 to 6, but the compound having a liquid carbon-carbon double bond is not cured, so that the resin over time on the cell It is thought that it was spreading.

  In Comparative Example 3, the component (B) was not included and the viscosity of the composition was low, so that the metal was precipitated. Therefore, other evaluations could not be performed.

  In Comparative Example 4, the stability of the paste was the same as in Examples 1 to 6, but the curing rate at 160 ° C. was fast and the metal could not aggregate. That is, the electrode of the solar battery cell and the wiring member are not electrically connected.

  DESCRIPTION OF SYMBOLS 1 ... Glass, 2 ... Sealing material, 3a, 3b ... Bus-bar electrode, 4 ... Wiring member, 5 ... Back sheet, 6 ... Semiconductor wafer, 7 ... Grid electrode, 8 ... Back electrode, 10 ... Conductive adhesive composition 20 ... solar cells, 30 ... connection body, 40 ... non-contact dispenser, 100 ... solar cell module.

Claims (12)

(A) conductive particles containing tin (Sn) and bismuth (Bi);
(B) a thermosetting resin that is solid at normal temperature (20 ° C.) and has a softening point of 120 ° C. or less;
(C) a compound that is liquid at room temperature (20 ° C.) and has a carbon-carbon double bond;
(D) a catalyst that accelerates curing of the component (C);
(E) A conductive adhesive composition containing a flux activator.   The conductive adhesive composition according to claim 1, wherein the component (B) is an epoxy resin.   The conductive adhesive composition according to claim 1 or 2, wherein the compound having a carbon-carbon double bond as the component (C) is a (meth) acrylic compound.   The conductive adhesive composition according to any one of claims 1 to 3, wherein the catalyst that accelerates the curing of the component (C) of the component (D) is a peroxide.   Furthermore, the conductive adhesive composition as described in any one of Claim 1 to 4 containing the catalyst which accelerates | stimulates hardening of (F) (B) component.   (F) The electrically conductive adhesive composition as described in any one of Claim 1 to 5 whose component is an imidazole compound.   The conductive adhesive composition according to any one of claims 1 to 6, which is used for electrically connecting an electrode of a solar battery cell and a metal conductor.   The conductive adhesive composition according to any one of claims 1 to 6, wherein a plurality of solar battery cells are connected to each other through a metal conductor, and the electrode of the solar battery cell and the metal conductor are provided. A connected body connected through an object.   It is a metal conducting wire with a conductive adhesive which consists of a metal conducting wire and the adhesive layer which coat | covers this metallic conducting wire, Comprising: The said adhesive bond layer is the electroconductivity as described in any one of Claim 1 to 6. Conductive adhesive-attached metal conductor comprising an adhesive using a conductive adhesive composition.   A connecting body comprising a plurality of solar cells and a metal wire with a conductive adhesive disposed on the electrode surface of the solar cells and electrically connecting the plurality of solar cells, The connection body whose metal conducting wire with a conductive adhesive is a metallic conducting wire with a conductive adhesive according to claim 9. A step of laminating a sealing material on both surfaces of the connection body according to claim 8 or 10,
Laminating glass on the sealing material on the light-receiving surface side of the solar cell, and laminating a protective film on the sealing material on the back surface of the solar cell
A step of sealing the solar battery cell while electrically connecting and bonding the solar battery cell and the metal conductive wire by heating the obtained laminate.   The solar cell module in which the electrode of the some photovoltaic cell and the metal conducting wire were electrically connected through the conductive adhesive composition as described in any one of Claim 1 to 6.

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