JP2008171760A - Silver conductive film and method for manufacturing same - Google Patents
Silver conductive film and method for manufacturing same Download PDFInfo
- Publication number
- JP2008171760A JP2008171760A JP2007005922A JP2007005922A JP2008171760A JP 2008171760 A JP2008171760 A JP 2008171760A JP 2007005922 A JP2007005922 A JP 2007005922A JP 2007005922 A JP2007005922 A JP 2007005922A JP 2008171760 A JP2008171760 A JP 2008171760A
- Authority
- JP
- Japan
- Prior art keywords
- silver
- conductive film
- particle dispersion
- silver conductive
- compound
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Granted
Links
Landscapes
- Parts Printed On Printed Circuit Boards (AREA)
- Paints Or Removers (AREA)
- Non-Insulated Conductors (AREA)
Abstract
Description
本発明は、銀導電膜およびその製造方法に関し、特に、基板上に銀粒子分散液を塗布して焼成することにより形成される銀導電膜およびその製造方法に関する。 The present invention relates to a silver conductive film and a method for manufacturing the same, and more particularly, to a silver conductive film formed by applying a silver particle dispersion on a substrate and baking it, and a method for manufacturing the same.
従来、電子部品などの電極や回路を形成する方法として、銀粉などの金属粉末をガラスフリットや無機酸化物とともに有機ビヒクル中に分散させたペーストを印刷やディッピングなどによって基板上に所定のパターンに形成した後、５００℃以上の温度で加熱することによって、有機成分を除去し、銀粒子などの金属粒子同士を焼結させて銀導電膜などの導電膜を形成する所謂厚膜ペースト法が広く用いられている。このような厚膜ペースト法によって形成された導電膜と基板との密着性は、焼成工程において軟化して流動したガラスフリットが基板を濡らすことによって、また、配線を形成する金属の焼結膜中にも軟化して流動したガラスフリットが浸透すること（ガラスボンド）によって確保されている。 Conventionally, as a method of forming electrodes and circuits for electronic components, a paste in which metal powder such as silver powder is dispersed in an organic vehicle together with glass frit or inorganic oxide is formed in a predetermined pattern on a substrate by printing or dipping. Then, a so-called thick film paste method is widely used in which an organic component is removed by heating at a temperature of 500 ° C. or higher, and metal particles such as silver particles are sintered together to form a conductive film such as a silver conductive film. It has been. The adhesion between the conductive film formed by such a thick film paste method and the substrate is because the glass frit softened and fluidized in the baking process wets the substrate, and in the sintered metal film forming the wiring. It is ensured by the penetration of glass frit that has softened and fluidized (glass bond).
また、金属粒子の粒径が数ｎｍ程度になると、比表面積が非常に大きくなって、融点が劇的に低下する。そのため、粒径が数ｎｍ程度の金属粒子を使用して導電膜を形成すると、粒径が数μｍ程度の金属粒子を使用した場合と比べて、微細な導電膜の配線の描画が可能になるだけでなく、３００℃以下の低温で焼成しても金属粒子同士を焼結させることもできる。 Further, when the particle size of the metal particles is about several nm, the specific surface area becomes very large and the melting point is drastically lowered. Therefore, when a conductive film is formed using metal particles having a particle size of about several nanometers, finer conductive film wiring can be drawn as compared to the case where metal particles having a particle size of about several μm are used. In addition, the metal particles can be sintered even when fired at a low temperature of 300 ° C. or lower.
しかし、３００℃以下の低い温度で焼成する場合には、従来の厚膜ペースト法と同様にガラスフリット添加しても、ガラスフリットの軟化点より低い温度であるため、ガラスフリットが軟化・流動しないので、基板を濡らすことがなく、基板に対する導電膜の密着性が悪いという問題がある。 However, when firing at a low temperature of 300 ° C. or lower, even if glass frit is added as in the conventional thick film paste method, the glass frit does not soften or flow because the temperature is lower than the softening point of the glass frit. Therefore, there is a problem that the substrate is not wetted and the adhesion of the conductive film to the substrate is poor.
この問題を解消する方法として、有機溶剤に金属微粒子が分散した金属微粒子分散液およびシランカップリング剤を含むペーストをガラス基板上に塗布して、２５０〜３００℃の温度で焼成することによってガラス基板上に金属薄膜を形成する方法（例えば、特許文献１参照）、平均粒子径０．５〜２０μｍの金属フィラーと平均粒子径１〜１００ｎｍの金属微粒子を熱硬化性樹脂中に分散させて導電性金属ペーストを形成する方法（例えば、特許文献２参照）などが提案されている。 As a method for solving this problem, a glass substrate is obtained by applying a paste containing a metal fine particle dispersion in which metal fine particles are dispersed in an organic solvent and a silane coupling agent on a glass substrate and baking at a temperature of 250 to 300 ° C. A method of forming a metal thin film thereon (see, for example, Patent Document 1), a metal filler having an average particle size of 0.5 to 20 μm and metal fine particles having an average particle size of 1 to 100 nm are dispersed in a thermosetting resin to be conductive. A method of forming a metal paste (see, for example, Patent Document 2) has been proposed.
しかし、特許文献１の方法では、ペーストにシランカップリング剤を添加しているので、ペーストの粘度が経時変化するという問題がある。また、特許文献２の方法では、ペーストに熱硬化性樹脂を使用しているので、このペーストを使用して形成した配線上に有機物が残存して誘電体層を形成すると、この配線を真空雰囲気中に配置した場合に、有機成分の脱離による誘電体層の膨れや真空雰囲気の環境汚染などによる回路の信頼性が低下することが懸念され、また、ペーストが樹脂を含んでいるために、ペーストの粘度を低くするのが困難であるという問題がある。 However, the method of Patent Document 1 has a problem that the viscosity of the paste changes with time because a silane coupling agent is added to the paste. Further, in the method of Patent Document 2, since a thermosetting resin is used for the paste, when the organic substance remains on the wiring formed using this paste to form a dielectric layer, the wiring is formed in a vacuum atmosphere. When placed inside, there is concern that the reliability of the circuit may decrease due to the swelling of the dielectric layer due to the desorption of organic components and environmental pollution of the vacuum atmosphere, and because the paste contains a resin, There is a problem that it is difficult to reduce the viscosity of the paste.
したがって、本発明は、このような従来の問題点に鑑み、シランカップリング剤や熱硬化性樹脂を加えることなく、３００℃以下の比較的低温で焼成しても、基板との密着性が良好である銀導電膜およびその製造方法を提供することを目的とする。 Therefore, in view of such a conventional problem, the present invention has good adhesion to a substrate even when baked at a relatively low temperature of 300 ° C. or less without adding a silane coupling agent or a thermosetting resin. It aims at providing the silver electrically conductive film which is these, and its manufacturing method.
本発明者らは、上記課題を解決するために鋭意研究した結果、アルコールまたはポリオール中において脂肪酸化合物およびアミン化合物の存在下で銀化合物を還元処理して生成した銀粒子を液状有機媒体中に分散させて第１の銀粒子分散液を用意し、アルコールまたはポリオール中においてアミン化合物の存在下で銀化合物を還元処理して生成した銀粒子を液状有機媒体中に分散させて第２の銀粒子分散液を用意し、第１の銀粒子分散液を基板上に塗布した後に焼成して基板上に第１の銀導電層を形成し、第２の銀粒子分散液を第１の銀導電層上に塗布した後に焼成して第１の銀導電層上に第２の銀導電層を形成することにより、シランカップリング剤や熱硬化性樹脂を加えることなく、３００℃以下の比較的低温で焼成しても、基板との密着性が良好である銀導電膜を製造することができることを見出し、本発明を完成するに至った。 As a result of diligent research to solve the above problems, the present inventors have dispersed silver particles produced by reducing a silver compound in an alcohol or polyol in the presence of a fatty acid compound and an amine compound in a liquid organic medium. The first silver particle dispersion is prepared, and the silver particles produced by reducing the silver compound in the presence of an amine compound in alcohol or polyol are dispersed in a liquid organic medium to form a second silver particle dispersion. A liquid is prepared, and the first silver particle dispersion is applied onto the substrate and then baked to form a first silver conductive layer on the substrate, and the second silver particle dispersion is applied to the first silver conductive layer. After being applied to the substrate, it is baked to form a second silver conductive layer on the first silver conductive layer, so that it is baked at a relatively low temperature of 300 ° C. or less without adding a silane coupling agent or a thermosetting resin. Even with the board It found that it is possible to sex to produce a silver conductive film is good, and have completed the present invention.
すなわち、本発明による銀導電膜の製造方法は、アルコールまたはポリオール中において脂肪酸化合物およびアミン化合物の存在下で銀化合物を還元処理して生成した銀粒子を液状有機媒体中に分散させて第１の銀粒子分散液を用意し、アルコールまたはポリオール中においてアミン化合物の存在下で銀化合物を還元処理して生成した銀粒子を液状有機媒体中に分散させて第２の銀粒子分散液を用意し、第１の銀粒子分散液を基板上に塗布した後に焼成して基板上に第１の銀導電層を形成し、第２の銀粒子分散液を第１の銀導電層上に塗布した後に焼成して第１の銀導電層上に第２の銀導電層を形成することを特徴とする。 That is, in the method for producing a silver conductive film according to the present invention, silver particles produced by reducing a silver compound in the presence of a fatty acid compound and an amine compound in alcohol or polyol are dispersed in a liquid organic medium. A silver particle dispersion is prepared, and silver particles produced by reducing the silver compound in the presence of an amine compound in alcohol or polyol are dispersed in a liquid organic medium to prepare a second silver particle dispersion. The first silver particle dispersion is applied onto the substrate and then baked to form a first silver conductive layer on the substrate, and the second silver particle dispersion is applied onto the first silver conductive layer and then baked. Then, the second silver conductive layer is formed on the first silver conductive layer.
この銀導電膜の製造方法において、還元処理が８０〜２００℃の温度で行われるのが好ましい。また、脂肪酸化合物の沸点が１００℃以上であり、アミン化合物の沸点が１５０〜４００℃であるのが好ましく、アルコールの沸点が８０〜２００℃であり、ポリオールの沸点が１５０〜３００℃であるのが好ましい。また、脂肪酸化合物およびアミン化合物の少なくとも一方が１分子中に１個以上の不飽和結合を有するのが好ましく、脂肪酸化合物およびアミン化合物が分子量１００〜１０００の化合物であるのが好ましい。また、還元処理の際に還元補助剤として２級アミンおよび３級アミンの少なくとも一方を添加するのが好ましい。さらに、焼成が酸化雰囲気中において１００〜３００℃の温度で行われるのが好ましい。 In this method for producing a silver conductive film, the reduction treatment is preferably performed at a temperature of 80 to 200 ° C. Moreover, it is preferable that the boiling point of a fatty acid compound is 100 degreeC or more, the boiling point of an amine compound is 150-400 degreeC, the boiling point of alcohol is 80-200 degreeC, and the boiling point of a polyol is 150-300 degreeC. Is preferred. In addition, at least one of the fatty acid compound and the amine compound preferably has one or more unsaturated bonds in one molecule, and the fatty acid compound and the amine compound are preferably compounds having a molecular weight of 100 to 1,000. In addition, it is preferable to add at least one of a secondary amine and a tertiary amine as a reduction aid during the reduction treatment. Further, the firing is preferably performed at a temperature of 100 to 300 ° C. in an oxidizing atmosphere.
また、本発明による銀導電膜は、脂肪酸化合物とアミン化合物とからなる有機保護剤を含む銀粒子が液状有機媒体中に分散した第１の銀粒子分散液を基板上に塗布して焼成することによって基板上に第１の銀導電層が形成され、アミン化合物からなる有機保護剤を含む銀粒子が液状有機媒体中に分散した第２の銀粒子分散液を第１の銀導電層上に塗布して焼成することによって第１の銀導電層上に第２の銀導電層が形成されていることを特徴とする。 In addition, the silver conductive film according to the present invention is obtained by applying a first silver particle dispersion liquid in which silver particles containing an organic protective agent composed of a fatty acid compound and an amine compound are dispersed in a liquid organic medium on a substrate and firing. A first silver conductive layer is formed on the substrate by applying a second silver particle dispersion liquid in which silver particles containing an organic protective agent composed of an amine compound are dispersed in a liquid organic medium on the first silver conductive layer. Then, the second silver conductive layer is formed on the first silver conductive layer by firing.
この銀導電膜において、脂肪酸化合物の沸点が１００℃以上であり、アミン化合物の沸点が１５０〜４００℃であるのが好ましい。また、脂肪酸化合物およびアミン化合物の少なくとも一方が１分子中に１個以上の不飽和結合を有するのが好ましく、脂肪酸化合物およびアミン化合物が分子量１００〜１０００の化合物であるのが好ましい。また、第１の銀粒子分散液の銀粒子中の有機保護剤の割合が１０〜４０質量％であり、第２の銀粒子分散液の銀粒子中の有機保護剤の割合が１０質量％未満であるのが好ましい。さらに、銀粒子の平均粒径（ＤＴＥＭ）が２０ｎｍ以下であるのが好ましい。 In this silver conductive film, the boiling point of the fatty acid compound is preferably 100 ° C. or higher, and the boiling point of the amine compound is preferably 150 to 400 ° C. In addition, at least one of the fatty acid compound and the amine compound preferably has one or more unsaturated bonds in one molecule, and the fatty acid compound and the amine compound are preferably compounds having a molecular weight of 100 to 1,000. Moreover, the ratio of the organic protective agent in the silver particles of the first silver particle dispersion is 10 to 40% by mass, and the ratio of the organic protective agent in the silver particles of the second silver particle dispersion is less than 10% by mass. Is preferred. Furthermore, it is preferable that the average particle diameter ( DTEM ) of silver particle is 20 nm or less.
本発明によれば、シランカップリング剤や熱硬化性樹脂を加えることなく、３００℃以下の比較的低温で焼成しても、基板との密着性が良好な銀導電膜を製造することができる。 According to the present invention, a silver conductive film having good adhesion to a substrate can be produced even when baked at a relatively low temperature of 300 ° C. or lower without adding a silane coupling agent or a thermosetting resin. .
本発明による銀導電膜の実施の形態では、沸点が８０〜２００℃のアルコールまたは沸点が１５０〜３００℃のポリオール中において、有機保護剤として沸点が１００℃以上、好ましくは２００℃以上、さらに好ましくは３００℃以上の脂肪酸化合物および沸点が１５０〜４００℃のアミン化合物の存在下で、銀化合物を８０〜２００℃の温度で還元処理して、生成した銀粒子を回収して沸点６０〜３００℃の非極性または極性の小さい液状有機媒体中に分散させてスラリーとし、このスラリーを固液分離して、平均粒径（ＤＴＥＭ）が２０ｎｍ以下の銀粒子が分散した下層用銀粒子分散液（第１の銀粒子分散液）を用意する。 In the embodiment of the silver conductive film according to the present invention, in an alcohol having a boiling point of 80 to 200 ° C or a polyol having a boiling point of 150 to 300 ° C, the boiling point is 100 ° C or higher, preferably 200 ° C or higher, more preferably as an organic protective agent. In the presence of a fatty acid compound of 300 ° C. or higher and an amine compound having a boiling point of 150 to 400 ° C., the silver compound is reduced at a temperature of 80 to 200 ° C., and the produced silver particles are recovered to have a boiling point of 60 to 300 ° C. In a non-polar or small-polar liquid organic medium, a slurry is obtained. The slurry is solid-liquid separated, and a silver particle dispersion for lower layer in which silver particles having an average particle size (D TEM ) of 20 nm or less are dispersed ( A first silver particle dispersion) is prepared.
また、沸点が８０〜２００℃のアルコールまたは沸点が１５０〜３００℃のポリオール中において、有機保護剤として沸点が１５０〜４００℃のアミン化合物の存在下で、銀化合物を８０〜２００℃の温度で還元処理して、生成した銀粒子を回収して沸点６０〜３００℃の非極性または極性の小さい液状有機媒体中に分散させてスラリーとし、このスラリーを固液分離して、平均粒径（ＤＴＥＭ）が２０ｎｍ以下の銀粒子が分散した上層用銀粒子分散液（第２の銀粒子分散液）を用意する。 Further, in an alcohol having a boiling point of 80 to 200 ° C or a polyol having a boiling point of 150 to 300 ° C, the silver compound is heated at a temperature of 80 to 200 ° C in the presence of an amine compound having a boiling point of 150 to 400 ° C as an organic protective agent. The silver particles produced by the reduction treatment are collected and dispersed in a non-polar or small-polar liquid organic medium having a boiling point of 60 to 300 ° C. to form a slurry, and the slurry is subjected to solid-liquid separation to obtain an average particle diameter (D An upper layer silver particle dispersion (second silver particle dispersion) in which silver particles having a TEM ) of 20 nm or less are dispersed is prepared.
次いで、下層用銀粒子分散液を基板上に塗布した後に１００〜３００℃の温度で焼成して基板上に第１の銀導電層を形成し、その後、上層用銀粒子分散液を第１の銀導電層上に塗布した後に１００〜３００℃の温度で焼成して第１の銀導電層上に第２の銀導電層を形成する。 Next, after applying the lower layer silver particle dispersion onto the substrate, firing is performed at a temperature of 100 to 300 ° C. to form a first silver conductive layer on the substrate, and then the upper layer silver particle dispersion is applied to the first layer. After apply | coating on a silver conductive layer, it bakes at the temperature of 100-300 degreeC, and forms a 2nd silver conductive layer on a 1st silver conductive layer.
アルコールまたはポリオール中において有機保護剤の存在下で銀化合物を還元処理すると、極性の小さい液状有機媒体中において極めて分散性の良い銀のナノ粒子（粒径２０ｎｍ以下の粒子）が得られる。使用する有機保護剤の種類を変えることにより、粒径の異なる銀のナノ粒子を得ることができる。このような粒径の小さい銀粒子が分散した液を基板上に塗布して塗膜を形成すると、銀の融点は約９６１℃であるにもかかわらず、塗膜を焼成する際に１００〜３００℃の低温で焼結が起こり、銀導電膜を形成することができる。また、使用する有機保護剤の種類や銀粒子中の有機保護剤の割合を変えることにより、導電性に優れた銀導電膜や密着性に優れた銀導電膜などの特性が異なる銀導電膜を形成することができる。したがって、密着性に優れた銀導電膜を基板上に形成する下層側の銀導電層とし、導電性に優れた銀導電膜をその上に形成する上層側の銀導電層とすることにより、比抵抗が５．０μΩ・ｃｍ以下の低抵抗で密着性に優れた銀導電膜を形成することができる。 When a silver compound is reduced in an alcohol or polyol in the presence of an organic protective agent, silver nanoparticles (particles having a particle size of 20 nm or less) having extremely good dispersibility in a liquid organic medium having a small polarity can be obtained. By changing the type of the organic protective agent used, silver nanoparticles having different particle diameters can be obtained. When a liquid in which silver particles having a small particle diameter are dispersed is applied onto a substrate to form a coating film, the silver has a melting point of about 961 ° C., but the coating film is baked at a temperature of 100 to 300. Sintering occurs at a low temperature of ° C., and a silver conductive film can be formed. In addition, by changing the type of organic protective agent used and the ratio of the organic protective agent in the silver particles, silver conductive films having different properties such as a silver conductive film having excellent conductivity and a silver conductive film having excellent adhesion can be obtained. Can be formed. Therefore, by making the silver conductive layer excellent in adhesion on the lower layer side silver conductive layer formed on the substrate, and the upper layer conductive layer forming the silver conductive layer excellent in conductivity thereon, the ratio A silver conductive film having a low resistance of 5.0 μΩ · cm or less and excellent adhesion can be formed.
アルコールまたはポリオールは、銀化合物の還元剤として機能するとともに、反応系の液状有機媒体としても機能する。アルコールとしては、プロピルアルコール、イソプロピルアルコール、ｎ−ブタノール、イソブタノール、ｓｅｃ−ブチルアルコール、ｔｅｒｔ−ブチルアルコール、アリルアルコール、クロチルアルコール、シクロペンタノールなどを使用することができる。ポリオール（複数の水酸基を有する多価アルコール）としては、ジエチレングリコール、トリエチレングリコール、テトラエチレングリコールなどを使用することができる。また、ポリオールの誘導体を使用することもできる。なお、Ａｇに対するアルコールまたはポリオールのモル比を０．５〜５０にするのが好ましい。 The alcohol or polyol functions as a reducing agent for the silver compound and also functions as a liquid organic medium for the reaction system. As the alcohol, propyl alcohol, isopropyl alcohol, n-butanol, isobutanol, sec-butyl alcohol, tert-butyl alcohol, allyl alcohol, crotyl alcohol, cyclopentanol and the like can be used. As the polyol (polyhydric alcohol having a plurality of hydroxyl groups), diethylene glycol, triethylene glycol, tetraethylene glycol, or the like can be used. Polyol derivatives can also be used. The molar ratio of alcohol or polyol to Ag is preferably 0.5-50.
有機保護剤として使用する脂肪酸化合物およびアミン化合物の少なくとも一方は、１分子中に１個以上の不飽和結合を有するのが好ましく、また、脂肪酸化合物およびアミン化合物は、分子量１００〜１０００の化合物であるのが好ましく、分子量が１００〜４００であるのがさらに好ましい。このような不飽和結合を有する脂肪酸化合物やアミン化合物を有機保護剤として使用することによって、還元反応において銀核を一斉に発生させるとともに、析出した銀核の成長を素早く抑制する現象が起こると考えられ、粒径２０ｎｍの小さい銀粒子を高収率で得ることができる。分子量が１００未満では、粒子の凝集抑制効果が低く、分子量が１０００を超えると、凝集抑制効果が高くても、銀粒子分散液を塗布して焼成するときに、粒子間の焼結を阻害して配線の抵抗が高くなってしまい、導電性がなくなる場合もある。脂肪酸化合物としては、オレイン酸、リノール酸、リノレン酸、パルミトレイン酸、ミリストレイン酸などを使用することができる。また、アミン化合物としては、トリアリルアミン、オレイルアミン、ジオレイルアミン、オレイルプロピレンジアミン、オクチルアミン、ノニルアミン、デシルアミン、ウンデシルアミン、ラウリルアミン、トリデシルアミン、テトラデシルアミン、ペンタデシルアミン、セチルアミンなどを使用することができる。なお、これらの脂肪酸化合物およびアミン化合物は、比較的低温で分解するので、銀粒子を低温で焼結させることができる。 At least one of the fatty acid compound and the amine compound used as the organic protective agent preferably has one or more unsaturated bonds in one molecule, and the fatty acid compound and the amine compound are compounds having a molecular weight of 100 to 1,000. It is preferable that the molecular weight is 100 to 400. The use of fatty acid compounds and amine compounds having such unsaturated bonds as an organic protective agent may cause a phenomenon in which silver nuclei are generated simultaneously in the reduction reaction and the growth of precipitated silver nuclei is quickly suppressed. Thus, small silver particles having a particle diameter of 20 nm can be obtained with high yield. When the molecular weight is less than 100, the effect of suppressing aggregation of particles is low, and when the molecular weight exceeds 1000, even when the effect of suppressing aggregation is high, sintering between particles is inhibited when the silver particle dispersion is applied and fired. As a result, the resistance of the wiring becomes high and the conductivity may be lost. As the fatty acid compound, oleic acid, linoleic acid, linolenic acid, palmitoleic acid, myristoleic acid and the like can be used. As the amine compound, triallylamine, oleylamine, dioleylamine, oleylpropylenediamine, octylamine, nonylamine, decylamine, undecylamine, laurylamine, tridecylamine, tetradecylamine, pentadecylamine, cetylamine, etc. are used. be able to. In addition, since these fatty acid compounds and amine compounds are decomposed at a relatively low temperature, the silver particles can be sintered at a low temperature.
銀化合物の還元反応は、加熱によって反応媒体および還元剤としてのアルコールまたはポリオールの蒸発と凝縮を繰り返す還流条件下で（蒸発したアルコールまたはポリオールを液相に還流させながら）行われるのが好ましい。この還元反応を有機保護剤の存在下で行うことにより、有機保護剤で覆われた銀粒子を生成することができる。なお、Ａｇに対する有機保護剤のモル比を０．１〜２０にするのが好ましい。 The reduction reaction of the silver compound is preferably carried out under reflux conditions in which the reaction medium and the alcohol or polyol as the reducing agent are repeatedly evaporated and condensed by heating (while the evaporated alcohol or polyol is refluxed to the liquid phase). By performing this reduction reaction in the presence of an organic protective agent, silver particles covered with the organic protective agent can be generated. In addition, it is preferable to make the molar ratio of the organic protective agent with respect to Ag into 0.1-20.
銀化合物としては、銀塩または銀酸化物を使用することができ、硝酸銀、酸化銀、炭酸銀などを使用するのが好ましく、工業的観点から硝酸銀を使用するのが好ましい。還元反応時の液中のＡｇイオン濃度は、０．０５モル／Ｌ以上であり、０．０５〜５．０モル／Ｌであるのが好ましい。 As the silver compound, a silver salt or a silver oxide can be used, and silver nitrate, silver oxide, silver carbonate or the like is preferably used, and silver nitrate is preferably used from an industrial viewpoint. The Ag ion concentration in the liquid during the reduction reaction is 0.05 mol / L or more, and preferably 0.05 to 5.0 mol / L.
また、還元処理は、還元補助剤の共存下で行うのが好ましい。この還元補助剤は、還元反応の終了近くで添加するのが好ましく、Ａｇに対する還元補助剤のモル比を０．１〜２０にするのが好ましい。還元補助剤として、分子量１００〜１０００のアミン化合物を使用するのが好ましく、アミン化合物の中でも還元力の強い２級アミンおよび３級アミンの少なくとも一方を使用するのがさらに好ましく、ジエタノールアミン、トリエタノールアミンなどを使用することができる。 The reduction treatment is preferably performed in the presence of a reducing aid. The reduction aid is preferably added near the end of the reduction reaction, and the molar ratio of the reduction aid to Ag is preferably 0.1-20. It is preferable to use an amine compound having a molecular weight of 100 to 1000 as a reduction auxiliary agent, and it is more preferable to use at least one of a secondary amine and a tertiary amine having a strong reducing power among the amine compounds, diethanolamine, triethanolamine. Etc. can be used.
上層用銀粒子分散液および下層用銀粒子分散液を用意するために、それぞれの還元反応後のスラリーを遠心分離器などで固液分離し、液を廃棄し、固体成分を回収する。この固体成分をメタノールなどの有機溶媒と混合して遠心分離器などで固液分離し、液を廃棄し、固体成分を回収することによって洗浄を行った。必要に応じて、この洗浄を繰り返し、最終的に得られた固体成分（沈殿物）を回収する。この固形成分を液状有機媒体と混合し、この液を遠心分離器などにより固液分離し、得られた液を（必要に応じて濃度調整して）それぞれ粒径分布が小さい銀粒子が分散している上層用銀粒子分散液および下層用銀分散液とする。 In order to prepare an upper layer silver particle dispersion and a lower layer silver particle dispersion, the slurries after the respective reduction reactions are subjected to solid-liquid separation using a centrifugal separator or the like, the liquid is discarded, and the solid components are recovered. This solid component was mixed with an organic solvent such as methanol and subjected to solid-liquid separation with a centrifugal separator or the like. The liquid was discarded, and the solid component was recovered to perform washing. This washing is repeated as necessary, and the finally obtained solid component (precipitate) is recovered. This solid component is mixed with a liquid organic medium, this liquid is solid-liquid separated by a centrifuge, etc., and the resulting liquid is dispersed with silver particles having a small particle size distribution (by adjusting the concentration if necessary). The upper layer silver particle dispersion and the lower layer silver dispersion are used.
液状有機媒体として、沸点が６０〜３００℃の非極性または極性の小さい液状有機媒体を使用するのが好ましい。本明細書中において、「非極性または極性の小さい」とは、２５℃における比誘電率が１５以下、好ましく５以下であることをいう。液状有機媒体の比誘電率が高い場合には、銀粒子の分散性が悪化して沈降する場合があるので好ましくない。液状有機媒体としては、銀粒子分散液の用途に応じて各種の液状有機媒体を使用することができるが、炭化水素系の液状有機媒体を使用するのが好ましく、イソオクタン、ｎ−デカン、イソドデカン、イソヘキサン、ｎ−ウンデカン、ｎ−テトラデカン、ｎ−ドデカン、トリデカン、ヘキサン、ヘプタンなどの脂肪族炭化水素や、ベンゼン、トルエン、キシレン、エチルベンゼン、デカリン、テトラリンなどの芳香族炭化水素などを使用することができる。これらの液状有機媒体を１種または２種以上使用することができ、ケロシンのような混合物を使用してもよい。また、液状有機媒体の極性を調整するために、回収した固体成分と混合した後の液状有機媒体の２５℃における比誘電率が１５以下になる範囲でアルコール系、ケトン系、エーテル系、エステル系などの極性有機媒体を添加してもよい。 As the liquid organic medium, it is preferable to use a non-polar or low-polar liquid organic medium having a boiling point of 60 to 300 ° C. In the present specification, “nonpolar or low polarity” means that the relative dielectric constant at 25 ° C. is 15 or less, preferably 5 or less. When the relative permittivity of the liquid organic medium is high, the dispersibility of the silver particles may be deteriorated and settle, which is not preferable. As the liquid organic medium, various liquid organic media can be used according to the use of the silver particle dispersion, but it is preferable to use a hydrocarbon-based liquid organic medium, such as isooctane, n-decane, isododecane, Use of aliphatic hydrocarbons such as isohexane, n-undecane, n-tetradecane, n-dodecane, tridecane, hexane, heptane, and aromatic hydrocarbons such as benzene, toluene, xylene, ethylbenzene, decalin, tetralin, etc. it can. One or more of these liquid organic media can be used, and a mixture such as kerosene may be used. In addition, in order to adjust the polarity of the liquid organic medium, alcoholic, ketone-based, ether-based, and ester-based liquid organic media after mixing with the recovered solid components have a relative dielectric constant at 25 ° C. of 15 or less. A polar organic medium such as may be added.
このようにして製造された下層用銀粒子分散液および上層用銀粒子分散液中の銀粒子は、それぞれ有機保護剤を含んでいる。 The silver particles in the lower layer silver particle dispersion and the upper layer silver particle dispersion thus produced each contain an organic protective agent.
透過電子顕微鏡（ＴＥＭ）観察により測定される銀粒子の平均粒径（ＤＴＥＭ）は、好ましくは２０ｎｍ以下、さらに好ましくは１０ｎｍ以下である。また、銀粒子の平均粒径（ＤＴＥＭ）は、Ａｇに対するアルコールまたはポリオールのモル比、Ａｇに対する有機保護剤のモル比、Ａｇに対する還元補助剤のモル比、還元反応時の昇温速度、攪拌力、銀化合物の種類、アルコールまたはポリオールの種類、還元補助剤の種類、有機保護剤の種類などによって制御することができる。 The average particle diameter (D TEM ) of the silver particles measured by observation with a transmission electron microscope (TEM) is preferably 20 nm or less, more preferably 10 nm or less. The average particle diameter (D TEM ) of the silver particles is the molar ratio of alcohol or polyol to Ag, the molar ratio of the organic protective agent to Ag, the molar ratio of the reducing aid to Ag, the heating rate during the reduction reaction, the stirring It can be controlled by force, type of silver compound, type of alcohol or polyol, type of reducing aid, type of organic protective agent, and the like.
下層用銀粒子分散液および上層用銀粒子分散液中の銀濃度は、５〜９０質量％であるのが好ましく、下層用銀粒子分散液および上層用銀粒子分散液の粘度は、１ｍＰａ・ｓ〜１００Ｐａ・ｓであるのが好ましい。 The silver concentration in the lower layer silver particle dispersion and the upper layer silver particle dispersion is preferably 5 to 90% by mass. The viscosity of the lower layer silver particle dispersion and the upper layer silver particle dispersion is 1 mPa · s. It is preferably ~ 100 Pa · s.
銀粒子中の有機保護剤の割合を変えることによって、形成される銀導電膜の特性を大きく変化させることができる。上層側の銀導電層の形成に使用される上層用銀粒子分散液中の銀粒子は、１級アミンからなる有機保護剤を含んでいる。上層側の銀導電層は、導電に関与しているため、有機保護剤の割合が高くなると、抵抗が高くなって好ましくないので、有機保護剤の割合が１０質量％未満であるのが好ましく、８質量％以下であるのがさらに好ましい。下層側の銀導電層の形成に使用される下層用銀粒子分散液中の銀粒子は、１級アミンと脂肪酸からなる有機保護剤を含んでいる。下層側の銀導電層は、基板との密着性に関与しているため、有機保護剤の割合が低過ぎると、焼結が進んで銀導電膜中に空孔が生じてしまい、密着性が悪化するので好ましくない。一方、有機保護剤の割合が高過ぎると、銀導電膜と基板の間の接触抵抗が高くなる傾向があるので好ましくない。そのため、下層用銀粒子分散液の銀粒子中の有機保護剤の割合は、１０〜４０質量％であるのが好ましく、１５〜３５質量％であるのがさらに好ましい。 By changing the proportion of the organic protective agent in the silver particles, the characteristics of the formed silver conductive film can be greatly changed. The silver particles in the upper layer silver particle dispersion used for forming the upper silver conductive layer contain an organic protective agent composed of a primary amine. Since the silver conductive layer on the upper layer side is involved in conduction, when the proportion of the organic protective agent is high, the resistance becomes high, which is not preferable. Therefore, the proportion of the organic protective agent is preferably less than 10% by mass, More preferably, it is 8 mass% or less. The silver particles in the lower layer silver particle dispersion used for forming the lower silver conductive layer contain an organic protective agent composed of a primary amine and a fatty acid. Since the lower silver conductive layer is involved in adhesion to the substrate, if the proportion of the organic protective agent is too low, sintering proceeds and voids are generated in the silver conductive film, resulting in adhesion. Since it deteriorates, it is not preferable. On the other hand, if the ratio of the organic protective agent is too high, the contact resistance between the silver conductive film and the substrate tends to increase, which is not preferable. Therefore, the proportion of the organic protective agent in the silver particles of the lower layer silver particle dispersion is preferably 10 to 40% by mass, and more preferably 15 to 35% by mass.
銀導電膜を形成する基板として、例えば、ガラス基板、フィルム状の有機高分子基板、シリコン基板、セラミックス基板などを使用することができる。ガラス基板は、二酸化ケイ素を主成分とする基板であれば特に限定しない。フィルム状の有機高分子基板としては、厚さは特に限定しないが、ロール・ツー・ロール方式に対応できるだけの可撓性を有し、高耐熱性を有するものが好ましく、ポリエチレンテレフタレート、ポリエチレンナフタレート、ポリイミド、アラミド、ポリカーボネートなどの基板を使用することができる。シリコン基板としては、アモルファスシリコン基板、多結晶シリコン基板、単結晶シリコン基板のいずれも使用することができる。セラミックス基板としては、アルミナ基板、窒化珪素基板などを使用することができる。 As the substrate for forming the silver conductive film, for example, a glass substrate, a film-like organic polymer substrate, a silicon substrate, a ceramic substrate, or the like can be used. The glass substrate is not particularly limited as long as it is a substrate mainly composed of silicon dioxide. The thickness of the film-like organic polymer substrate is not particularly limited, but is preferably flexible enough to be compatible with a roll-to-roll system and has high heat resistance, such as polyethylene terephthalate and polyethylene naphthalate. Substrates such as polyimide, aramid, and polycarbonate can be used. As the silicon substrate, any of an amorphous silicon substrate, a polycrystalline silicon substrate, and a single crystal silicon substrate can be used. As the ceramic substrate, an alumina substrate, a silicon nitride substrate, or the like can be used.
下層用銀粒子分散液および上層用銀粒子分散液を基板上に塗布する方法は、スピンコート法、ディップ法、ロールコート法、インクジェット法などの各種の塗布方法を使用することができるが、焼成後に銀導電膜を形成することができれば特に限定しない。 As a method of applying the lower layer silver particle dispersion and the upper layer silver particle dispersion on the substrate, various coating methods such as a spin coating method, a dip method, a roll coating method, and an ink jet method can be used. There is no particular limitation as long as a silver conductive film can be formed later.
塗布された塗膜を焼成して銀粒子を焼結させて銀導電膜を得るための焼成雰囲気は、大気雰囲気のような常圧の酸化雰囲気でよい。塗膜中の銀粒子は極めて低温で焼結するので、焼成温度は１００〜４００℃でよいが、使用可能な基板の種類を広げるとともに省エネルギーなどの観点から１００〜３００℃であるのが好ましい。塗膜を形成した基板を上記の温度域で保持する焼成時間は、１０分間以上であるのが好ましく、６０分間以上であるのがさらに好ましい。但し、焼成時間が長過ぎると生産性が悪くなるので、一般には３００分間以下であるのが好ましい。 The firing atmosphere for firing the coated film to sinter silver particles to obtain a silver conductive film may be an atmospheric oxidizing atmosphere such as an air atmosphere. Since the silver particles in the coating film are sintered at an extremely low temperature, the firing temperature may be 100 to 400 ° C., but it is preferably 100 to 300 ° C. from the viewpoints of energy saving and the like while expanding the types of substrates that can be used. The firing time for holding the substrate on which the coating film is formed in the above temperature range is preferably 10 minutes or more, and more preferably 60 minutes or more. However, if the firing time is too long, the productivity will deteriorate, so generally it is preferably 300 minutes or less.
銀導電膜は、低抵抗である程、効率的に電気を流すことができるので、比抵抗が低い方がよい。銀導電膜の比抵抗は、５．０μΩ・ｃｍ以下であるのが好ましく、４．０μΩ・ｃｍ以下でのがさらに好ましく、３．０μΩ・ｃｍ以下であるのがさらに好ましく、２．０μΩ・ｃｍ以下であるのが最も好ましい。 The lower the resistivity of the silver conductive film, the more efficiently electricity can flow. Therefore, it is better that the specific resistance is lower. The specific resistance of the silver conductive film is preferably 5.0 μΩ · cm or less, more preferably 4.0 μΩ · cm or less, further preferably 3.0 μΩ · cm or less, and 2.0 μΩ · cm. Most preferably:
銀導電膜の膜厚は０．１〜３．０μｍであるのが好ましく、０．５〜１．０μｍであるのがさらに好ましい。膜厚が０．１μｍより薄くなると、大電流を流すには不向きであり、膜厚が３．０μｍより厚くなると、銀導電膜の厚さのばらつきが非常に大きくなる。また、上層側の銀導電層と下層側の銀導電層の厚さの比は、一方の厚さが極端に大きくなると銀導電膜全体の特性が極端に厚い側の銀導電層の特性になってしまい、低抵抗で密着性の良好な銀導電膜を得ることができなくなるので、両者の厚さの比が４０：６０〜６０：４０であるのが好ましく、５０：５０に近いほど好ましい。 The film thickness of the silver conductive film is preferably from 0.1 to 3.0 [mu] m, more preferably from 0.5 to 1.0 [mu] m. When the film thickness is thinner than 0.1 μm, it is unsuitable for flowing a large current, and when the film thickness is thicker than 3.0 μm, the variation in the thickness of the silver conductive film becomes very large. In addition, the ratio of the thickness of the upper silver conductive layer to the lower silver conductive layer is such that when one of the thicknesses becomes extremely large, the characteristics of the entire silver conductive film become the characteristics of the extremely thick silver conductive layer. As a result, a silver conductive film having low resistance and good adhesion cannot be obtained. Therefore, the thickness ratio between the two is preferably 40:60 to 60:40, more preferably closer to 50:50.
以下、本発明による銀導電膜およびその製造方法の実施例について詳細に説明する。 Hereinafter, the Example of the silver electrically conductive film by this invention and its manufacturing method is described in detail.
［実施例１］
反応媒体および還元剤としてのイソブタノール（和光純薬株式会社製）９６ｇに、有機保護剤としてのオレイルアミン（和光純薬株式会社製）１６５ｇと、銀化合物としての硝酸銀結晶（関東化学株式会社製）２１ｇを添加し、マグネットスターラーで攪拌して硝酸銀を溶解させた。次に、この溶液を還流器付の容器に移し、この容器内に不活性ガスとして窒素ガスを４００ｍＬ／分の流量で吹込みながら、溶液をマグネットスターラーにより１００ｒｐｍの回転速度で撹拌しながら、昇温速度２℃／分で１００℃まで加熱した。１００℃で３時間還流した後、還元補助剤として２級アミンであるジエタノールアミン（和光純薬株式会社製）１３ｇを添加し、１時間保持して反応を終了した。反応終了後のスラリーを遠心分離器で固液分離して、液を廃棄し、固体成分を回収した。この固体成分をメタノールと混合して遠心分離器で固液分離し、液を廃棄し、固体成分を回収することによって洗浄を行った。この洗浄を２回繰り返した後の固形成分を、２５℃の比誘電率が１５以下の液状有機媒体としてｎ−テトラデカン（沸点約２５０℃）に混合し、遠心分離器で３０分間固液分離し、銀粒子が分散した液を回収した。なお、回収した液は、後述するように上層用銀粒子分散液として使用した。
[Example 1]
96 g of isobutanol (manufactured by Wako Pure Chemical Industries, Ltd.) as a reaction medium and a reducing agent, 165 g of oleylamine (manufactured by Wako Pure Chemical Industries, Ltd.) as an organic protective agent, and silver nitrate crystals (manufactured by Kanto Chemical Co., Ltd.) as a silver compound 21 g was added and stirred with a magnetic stirrer to dissolve silver nitrate. Next, this solution is transferred to a container equipped with a refluxer, and nitrogen gas is blown into the container as an inert gas at a flow rate of 400 mL / min, and the solution is stirred while stirring at a rotation speed of 100 rpm with a magnetic stirrer. Heated to 100 ° C. at a temperature rate of 2 ° C./min. After refluxing at 100 ° C. for 3 hours, 13 g of secondary ethanol diethanolamine (manufactured by Wako Pure Chemical Industries, Ltd.) was added as a reduction auxiliary agent, and the reaction was terminated by maintaining for 1 hour. The slurry after the reaction was subjected to solid-liquid separation with a centrifuge, the liquid was discarded, and the solid components were recovered. This solid component was mixed with methanol and subjected to solid-liquid separation with a centrifuge, and the liquid was discarded, and the solid component was recovered to perform washing. The solid component after repeating this washing twice is mixed with n-tetradecane (boiling point: about 250 ° C.) as a liquid organic medium having a relative dielectric constant of 15 ° C. or less at 25 ° C., and solid-liquid separated for 30 minutes by a centrifuge. A liquid in which silver particles were dispersed was collected. The recovered liquid was used as an upper layer silver particle dispersion as described later.
この上層用銀粒子分散液を透過電子顕微鏡（ＴＥＭ）により約６０万倍の倍率で観察した画像において、他の粒子と重なっていない独立した粒子をランダムに３００個以上選択して、個々の粒子の直径（画像上に現れる粒子を囲む外接円のうち最も直径の小さい外接円の直径）を測定し、その平均値を算出することによって、上層用銀粒子分散液中の銀粒子の平均粒径（ＤＴＥＭ）を求めた。また、回転式粘度計（東機産業製のＲＥ５５０Ｌ）によって上層用銀粒子分散液の粘度を測定した。さらに、熱重量分析装置（マックサイエンス社製のＴＧ−ＤＴＡ２０００）によって上層用銀粒子分散液を１０℃／分で２００℃まで昇温した後に１時間保持し、さらに１０℃／分で７００℃まで昇温し、２００℃までに減少した重量を溶媒の重量とし、２００〜７００℃の間に減少した重量を有機保護剤の重量とし、７００℃で残っていた重量を銀重量として、上層用銀粒子分散液中の銀濃度および銀粒子中の有機保護剤の割合を以下の式によって算出した。
銀濃度（質量％）＝｛銀の重量／（溶媒の重量＋有機保護剤の重量＋銀の重量）｝×１００
有機保護剤の割合（質量%）
＝｛有機保護剤の重量／（有機保護剤の重量＋銀の重量）｝×１００
In an image obtained by observing the upper layer silver particle dispersion with a transmission electron microscope (TEM) at a magnification of about 600,000 times, 300 or more independent particles that do not overlap with other particles are randomly selected to obtain individual particles. The average particle diameter of the silver particles in the upper layer silver particle dispersion is measured by measuring the diameter (the diameter of the circumscribed circle having the smallest diameter among the circumscribed circles surrounding the particles appearing on the image) and calculating the average value thereof. (D TEM ) was determined. Further, the viscosity of the upper layer silver particle dispersion was measured with a rotary viscometer (RE550L manufactured by Toki Sangyo). Further, the temperature of the upper layer silver particle dispersion was raised to 200 ° C. at 10 ° C./min with a thermogravimetric analyzer (TG-DTA2000 manufactured by Mac Science) and then held for 1 hour, and further up to 700 ° C. at 10 ° C./min. The temperature is increased, the weight reduced to 200 ° C. is defined as the weight of the solvent, the weight reduced between 200 ° C. and 700 ° C. is defined as the weight of the organic protective agent, and the weight remaining at 700 ° C. is defined as the silver weight. The silver concentration in the particle dispersion and the ratio of the organic protective agent in the silver particles were calculated by the following formula.
Silver concentration (mass%) = {silver weight / (solvent weight + organic protective agent weight + silver weight)} × 100
Ratio of organic protective agent (% by mass)
= {Weight of organic protective agent / (weight of organic protective agent + weight of silver)} × 100
その結果、上層用銀粒子分散液の粘度は８．１ｍＰａ・ｓ、上層用銀粒子分散液中の銀濃度は６４．８質量％、上層用銀粒子分散液中の銀粒子の平均粒径（ＤＴＥＭ）は８．５ｎｍ、銀粒子中の有機保護剤の割合は７．５質量％であった。 As a result, the viscosity of the upper layer silver particle dispersion was 8.1 mPa · s, the silver concentration in the upper layer silver particle dispersion was 64.8% by mass, and the average particle diameter of the silver particles in the upper layer silver particle dispersion ( D TEM ) was 8.5 nm, and the ratio of the organic protective agent in the silver particles was 7.5% by mass.
また、反応媒体および還元剤としてのイソブタノール（和光純薬化学株式会社製）６４ｇに、有機保護剤としてのオレイルアミン（和光純薬株式会社製）１１１ｇおよびオレイン酸（和光純薬株式会社製）２３ｇと、銀化合物としての硝酸銀結晶（関東化学株式会社製）１４ｇを添加し、マグネットスターラーで攪拌して硝酸銀を溶解させた。次に、この溶液を還流器付の容器に移し、この容器内に不活性ガスとして窒素ガスを４００ｍＬ／分の流量で吹込みながら、溶液をマグネットスターラーにより１００ｒｐｍの回転速度で撹拌しながら、昇温速度２℃／分で１００℃まで加熱した。１００℃で３時間還流した後、還元補助剤として２級アミンであるジエタノールアミン（和光純薬株式会社製）９ｇを添加し、１時間保持して反応を終了した。反応終了後のスラリーにメタノールを加えて固液分離し、液を廃棄し、固体成分を回収した。この固体成分をメタノールと混合して遠心分離器で固液分離し、液を廃棄し、固体成分を回収することによって洗浄を行った。この洗浄を２回繰り返した後の固形成分を、２５℃の比誘電率が１５以下の液状有機媒体としてｎ−ドデカン（沸点約２１０℃）に混合し、遠心分離器で３０分間固液分離し、銀粒子が分散した液を回収した。なお、回収した液は、後述するように下層用銀粒子分散液として使用した。 In addition, 64 g of isobutanol (manufactured by Wako Pure Chemical Industries, Ltd.) as a reaction medium and a reducing agent, 111 g of oleylamine (manufactured by Wako Pure Chemical Industries, Ltd.) as an organic protective agent, and 23 g of oleic acid (manufactured by Wako Pure Chemical Industries, Ltd.) Then, 14 g of silver nitrate crystal (manufactured by Kanto Chemical Co., Inc.) as a silver compound was added and stirred with a magnetic stirrer to dissolve the silver nitrate. Next, this solution is transferred to a container equipped with a refluxer, and nitrogen gas is blown into the container as an inert gas at a flow rate of 400 mL / min, and the solution is stirred while stirring at a rotation speed of 100 rpm with a magnetic stirrer. Heated to 100 ° C. at a temperature rate of 2 ° C./min. After refluxing at 100 ° C. for 3 hours, 9 g of diethanolamine (manufactured by Wako Pure Chemical Industries, Ltd.), which is a secondary amine, was added as a reducing auxiliary agent, and the reaction was terminated by maintaining for 1 hour. Methanol was added to the slurry after completion of the reaction for solid-liquid separation, the liquid was discarded, and the solid components were recovered. This solid component was mixed with methanol and subjected to solid-liquid separation with a centrifuge, and the liquid was discarded, and the solid component was recovered to perform washing. The solid component after repeating this washing twice is mixed with n-dodecane (boiling point: about 210 ° C.) as a liquid organic medium having a relative dielectric constant of 15 ° C. or less at 25 ° C., and solid-liquid separated for 30 minutes by a centrifuge. A liquid in which silver particles were dispersed was collected. The recovered liquid was used as a lower layer silver particle dispersion as described later.
得られた下層用銀粒子分散液について、上層用銀粒子分散液の場合と同様の方法によって、粘度、銀濃度、銀粒子の平均粒径（ＤＴＥＭ）および銀粒子中の有機保護剤の割合を求めたところ、下層用銀粒子分散液の粘度は１１．７ｍＰａ・ｓ、下層用銀粒子分散液中の銀濃度は４６．９質量％、下層用銀粒子分散液中の銀粒子の平均粒径（ＤＴＥＭ）は４．１ｎｍ、銀粒子中の有機保護剤の割合は３１．１質量％であった。 For the obtained silver particle dispersion for the lower layer, the viscosity, the silver concentration, the average particle diameter (D TEM ) of the silver particles, and the ratio of the organic protective agent in the silver particles are the same as in the case of the silver particle dispersion for the upper layer. The lower layer silver particle dispersion had a viscosity of 11.7 mPa · s, the lower layer silver particle dispersion had a silver concentration of 46.9% by mass, and the lower layer silver particle dispersion had an average particle size of silver particles. The diameter (D TEM ) was 4.1 nm, and the ratio of the organic protective agent in the silver particles was 31.1% by mass.
なお、カルボニル基、アミノ基、長鎖アルキル基、不飽和結合を確認可能な１Ｈおよび１３Ｃ−ＮＭＲ測定と、分子量を同定可能な熱分解ガスクロマトグラフ質量分析測定によって、本実施例および後述する実施例２で得られた上層用銀粒子分散液および下層用銀粒子分散液中の銀粒子が有機保護剤を含むことを確認した。 Incidentally, a carbonyl group, an amino group, a long chain alkyl group, and identifiable 1 H and 13 C-NMR measurement of unsaturated bonds, with identifiable pyrolysis gas chromatography mass spectrometry determination of molecular weight, for this example and later It was confirmed that the silver particles in the upper layer silver particle dispersion and the lower layer silver particle dispersion obtained in Example 2 contained an organic protective agent.
次に、ガラス基板としてスライドグラス（松浪ガラス製のＳ−７１２３）を用意し、このガラス基板上に下層用銀粒子分散液をスピンコータで塗布した後、ホットプレート（ＡＳ−ＯＮＥ製のＨＰ−１Ｌ）によって２００℃で６０分間焼成して銀粒子を焼結させることにより、ガラス基板上に銀導電膜を形成した。 Next, a slide glass (S-7123 made by Matsunami Glass) was prepared as a glass substrate, and the lower layer silver particle dispersion was applied on the glass substrate with a spin coater, and then a hot plate (HP-1L made by AS-ONE). ) Was sintered at 200 ° C. for 60 minutes to sinter the silver particles, thereby forming a silver conductive film on the glass substrate.
次に、ガラス基板上に形成された銀導電膜上に上層用銀粒子分散液をスピンコータで塗布した後、ホットプレートによって２００℃で６０分間焼成をして、銀粒子を焼結させることにより、ガラス基板上に形成された銀導電膜上にさらに銀導電膜を形成した。 Next, after applying the upper layer silver particle dispersion liquid on the silver conductive film formed on the glass substrate with a spin coater, firing at 200 ° C. for 60 minutes with a hot plate to sinter the silver particles, A silver conductive film was further formed on the silver conductive film formed on the glass substrate.
得られた銀導電膜について、膜厚、比抵抗、炭素の有無およびガラス基板との密着性を評価した。銀導電膜の膜厚は、蛍光Ｘ線膜厚測定器（ＳＩＩ社製の蛍光Ｘ線膜厚測定器ＳＦＴ９２００）によって測定した。銀導電膜の比抵抗は、表面抵抗測定装置（三菱化学製のロレスタＨＰ）で測定した表面抵抗と膜厚測定器で得られた膜厚から計算により求めた。銀導電膜中の炭素の有無は、Ｘ線光電子分光器（アルバック・ファイ社製のＥＳＣＡ５８００）を使用して、Ｘ線光電子分光（ＥＳＣＡ）法により、銀導電膜の最表面から１／４（上層）および３／４（下層）の深さ領域における炭素のエネルギー２８４．３ｅＶおよび２８４．５ｅＶのピークの有無を調べることによって行った。なお、ＥＳＣＡの測定条件については、Ｘ線源として１５００ＷのＡｌ陽極線源を使用し、分析エリアを４００μｍφｓとし、中和銃を使用し、取り出し角を４５°とし、Ａｒスパッタエッチング速度を４０ｎｍ／分（ＳｉＯ２換算値）とした。また、銀導電膜のガラス基板との密着性は、カッターにより銀導電膜上に１ｍｍ角の升目１００個を作製し、その上にセロハン粘着テープ（ＪＩＳ Ｚ１５２２に規定されている幅２５ｍｍ当たりの粘着量が約８Ｎのテープ）を圧着した後に剥離し、残存する升目の数ｘを数え、ｘ／１００として評価した。 About the obtained silver electrically conductive film, the film thickness, specific resistance, the presence or absence of carbon, and adhesiveness with a glass substrate were evaluated. The film thickness of the silver conductive film was measured with a fluorescent X-ray film thickness measuring instrument (fluorescent X-ray film thickness measuring instrument SFT9200 manufactured by SII). The specific resistance of the silver conductive film was determined by calculation from the surface resistance measured with a surface resistance measuring device (Loresta HP manufactured by Mitsubishi Chemical) and the film thickness obtained with the film thickness measuring instrument. The presence or absence of carbon in the silver conductive film is determined from the outermost surface of the silver conductive film by an X-ray photoelectron spectrometer (ESCA 5800) using an X-ray photoelectron spectrometer (ESCA5800 manufactured by ULVAC-PHI). This was performed by examining the presence or absence of peaks of carbon energy 284.3 eV and 284.5 eV in the depth region of the upper layer) and 3/4 (lower layer). The ESCA measurement conditions were as follows: an Al anode source of 1500 W was used as the X-ray source, the analysis area was 400 μmφs, a neutralization gun was used, the take-off angle was 45 °, and the Ar sputter etching rate was 40 nm / Minute (SiO 2 equivalent value). In addition, the adhesion of the silver conductive film to the glass substrate is such that 100 squares of 1 mm square are produced on the silver conductive film with a cutter, and the cellophane adhesive tape (adhesion per 25 mm width defined in JIS Z1522 is formed thereon. (Tape having an amount of about 8N) was peeled off after being pressed, and the number x of the remaining squares was counted and evaluated as x / 100.
その結果、銀導電膜の膜厚は７００ｎｍ、上下の膜厚比は５０：５０であり、比抵抗は４．２μΩ・ｃｍと低く、上層には炭素はなく、下層には炭素が存在し、ガラス基板との密着性は１００／１００で良好であった。 As a result, the film thickness of the silver conductive film is 700 nm, the upper and lower film thickness ratio is 50:50, the specific resistance is as low as 4.2 μΩ · cm, the upper layer has no carbon, the lower layer has carbon, Adhesion with the glass substrate was 100/100 and good.
［実施例２］
反応媒体および還元剤としてのイソブタノール（和光純薬化学株式会社製）８０ｇに、有機保護剤としてのオクチルアミン（和光純薬株式会社製）６６ｇおよびオレイン酸（和光純薬株式会社製）２９ｇと、銀化合物としての硝酸銀結晶（関東化学株式会社製）１７ｇを添加し、マグネットスターラーで攪拌して硝酸銀を溶解させた。次に、この溶液を還流器付の容器に移し、この容器内に不活性ガスとして窒素ガスを４００ｍＬ／分の流量で吹込みながら、溶液をマグネットスターラーにより１００ｒｐｍの回転速度で撹拌しながら、昇温速度２℃／分で１００℃まで加熱した。１００℃で３時間還流した後、還元補助剤として２級アミンであるジエタノールアミン（和光純薬株式会社製）３２ｇを添加し、１時間保持して反応を終了した。反応終了後のスラリーにメタノールを加えて固液分離し、液を廃棄し、固体成分を回収した。この固体成分をメタノールと混合して遠心分離器で固液分離し、液を廃棄し、固体成分を回収することによって洗浄を行った。この洗浄を２回繰り返した後の固形成分を、２５℃の比誘電率が１５以下の液状有機媒体としてｎ−ドデカン（沸点約２１０℃）に混合し、遠心分離器で３０分間固液分離し、銀粒子が分離した液を回収した。
[Example 2]
80 g of isobutanol (manufactured by Wako Pure Chemical Industries, Ltd.) as a reaction medium and a reducing agent, 66 g of octylamine (manufactured by Wako Pure Chemical Industries, Ltd.) as an organic protective agent, and 29 g of oleic acid (manufactured by Wako Pure Chemical Industries, Ltd.) Then, 17 g of silver nitrate crystal (manufactured by Kanto Chemical Co., Inc.) as a silver compound was added and stirred with a magnetic stirrer to dissolve the silver nitrate. Next, this solution is transferred to a container equipped with a refluxer, and nitrogen gas is blown into the container as an inert gas at a flow rate of 400 mL / min, and the solution is stirred while stirring at a rotation speed of 100 rpm with a magnetic stirrer. Heated to 100 ° C. at a temperature rate of 2 ° C./min. After refluxing at 100 ° C. for 3 hours, 32 g of diethanolamine (manufactured by Wako Pure Chemical Industries, Ltd.), which is a secondary amine, was added as a reducing auxiliary agent, and the reaction was terminated by maintaining for 1 hour. Methanol was added to the slurry after completion of the reaction for solid-liquid separation, and the liquid was discarded to recover the solid components. This solid component was mixed with methanol and subjected to solid-liquid separation with a centrifuge, and the liquid was discarded, and the solid component was recovered to perform washing. The solid component after repeating this washing twice is mixed with n-dodecane (boiling point: about 210 ° C.) as a liquid organic medium having a relative dielectric constant of 15 ° C. or less at 25 ° C., and solid-liquid separated for 30 minutes by a centrifuge. The liquid from which the silver particles were separated was collected.
この回収した液を下層用銀粒子分散液として使用するとともに、実施例１と同様の上層用銀粒子分散液を使用して、実施例１と同様の方法によってガラス基板上に銀導電膜を形成した。 The recovered liquid is used as a lower layer silver particle dispersion, and an upper layer silver particle dispersion similar to that in Example 1 is used to form a silver conductive film on a glass substrate in the same manner as in Example 1. did.
得られた下層用銀粒子分散液について、上層用銀粒子分散液の場合と同様の方法によって、粘度、銀濃度、銀粒子の平均粒径（ＤＴＥＭ）および銀粒子中の有機保護剤の割合を求めたところ、下層用銀粒子分散液の粘度は５．１ｍＰａ・ｓ、下層用銀粒子分散液中の銀濃度は４９．５質量％、下層用銀粒子分散液中の銀粒子の平均粒径（ＤＴＥＭ）は６．１ｎｍ、銀粒子中の有機保護剤の割合は１９．８質量％であった。 For the obtained silver particle dispersion for the lower layer, the viscosity, the silver concentration, the average particle diameter (D TEM ) of the silver particles, and the ratio of the organic protective agent in the silver particles are the same as in the case of the silver particle dispersion for the upper layer. The lower layer silver particle dispersion has a viscosity of 5.1 mPa · s, the lower layer silver particle dispersion has a silver concentration of 49.5% by mass, and the average particle size of the silver particles in the lower layer silver particle dispersion is The diameter (D TEM ) was 6.1 nm, and the ratio of the organic protective agent in the silver particles was 19.8% by mass.
また、得られた銀導電膜について、実施例１と同様の方法により、膜厚、比抵抗、炭素の有無およびガラス基板との密着性を評価した。その結果、銀導電膜の膜厚は９００ｎｍ、上下の膜厚比は５０：５０であり、比抵抗は３．３μΩ・ｃｍと低く、上層には炭素はなく、下層には炭素が存在し、ガラス基板との密着性は１００／１００で良好であった。 Moreover, about the obtained silver electrically conductive film, the film thickness, specific resistance, the presence or absence of carbon, and adhesiveness with a glass substrate were evaluated by the same method as Example 1. As a result, the thickness of the silver conductive film is 900 nm, the upper and lower film thickness ratio is 50:50, the specific resistance is as low as 3.3 μΩ · cm, the upper layer has no carbon, and the lower layer has carbon. Adhesion with the glass substrate was 100/100 and good.
［比較例１］
下層用銀粒子分散液を使用しなかった以外は、実施例１と同様の方法によって、ガラス基板上に単一層構造の銀導電膜を形成し、得られた銀導電膜について、実施例１と同様の方法により、膜厚、比抵抗、炭素の有無およびガラス基板との密着性を評価した。なお、銀導電膜中の炭素の有無は、銀導電膜の最表面から１／４の地点で判断した。その結果、銀導電膜の膜厚は９４０ｎｍであり、比抵抗は２．７μΩ・ｃｍと低く、上層に炭素はなかったが、ガラス基板との密着性は０／１００で不十分であった。
[Comparative Example 1]
A silver conductive film having a single layer structure was formed on a glass substrate by the same method as in Example 1 except that the lower layer silver particle dispersion was not used. By the same method, the film thickness, specific resistance, presence / absence of carbon, and adhesion to a glass substrate were evaluated. In addition, the presence or absence of carbon in the silver conductive film was determined at a point ¼ from the outermost surface of the silver conductive film. As a result, the film thickness of the silver conductive film was 940 nm, the specific resistance was as low as 2.7 μΩ · cm, and there was no carbon in the upper layer, but the adhesion with the glass substrate was 0/100, which was insufficient.
［比較例２］
上層用銀粒子分散液を使用しなかった以外は、実施例１と同様の方法によって、ガラス基板上に単一層構造の銀導電膜を形成し、得られた銀導電膜について、実施例１と同様の方法により、膜厚、比抵抗、炭素の有無およびガラス基板との密着性を評価した。なお、銀導電膜中の炭素の有無は、銀導電膜の最表面から１／４の地点で判断した。その結果、銀導電膜の膜厚は３２０ｎｍであり、比抵抗は９．５μΩ・ｃｍと高く、上層に炭素が存在し、ガラス基板との密着性は１００／１００で良好であった。
[Comparative Example 2]
A silver conductive film having a single layer structure was formed on a glass substrate by the same method as in Example 1 except that the upper layer silver particle dispersion was not used. By the same method, the film thickness, specific resistance, presence / absence of carbon, and adhesion to a glass substrate were evaluated. In addition, the presence or absence of carbon in the silver conductive film was determined at a point ¼ from the outermost surface of the silver conductive film. As a result, the film thickness of the silver conductive film was 320 nm, the specific resistance was as high as 9.5 μΩ · cm, carbon was present in the upper layer, and the adhesion with the glass substrate was 100/100, which was good.
本発明による銀導電膜は、ＬＳＩ基板の配線、ＦＰＤ（フラットパネルディスプレイ）の電極や配線、微細なトレンチ、ビアホール、コンタクトホールの埋め込みなどの配線形成材料として利用することができる。また、車の塗装などの色材としても利用することができ、医療、診断、バイオテクノロジーなどの分野において生化学物質などを吸着させるキャリアにも利用することができる。 The silver conductive film according to the present invention can be used as a wiring forming material for LSI substrate wiring, FPD (flat panel display) electrodes and wiring, fine trenches, via holes, and contact hole filling. It can also be used as a coloring material for car paints, and can also be used as a carrier for adsorbing biochemical substances in fields such as medical treatment, diagnosis, and biotechnology.
また、本発明による銀導電膜は、低温焼成が可能であるため、フレキシブルなフィルム上への電極形成材料として利用することができ、エレクトロニクス実装においては、接合材として利用することもできる。さらに、導電性皮膜として電磁波シールド膜や、透明導電膜などの分野における光学特性を利用した赤外線反射シールドなどにも利用することができ、ガラス基板上に印刷して焼成し、自動車ウインドウの防曇用熱線などにも利用することができる。
In addition, since the silver conductive film according to the present invention can be fired at a low temperature, it can be used as an electrode forming material on a flexible film, and can also be used as a bonding material in electronic packaging. Furthermore, it can also be used as an electromagnetic wave shielding film as a conductive film and an infrared reflection shield using optical characteristics in the field of transparent conductive film, etc., printed on a glass substrate and baked to prevent fogging of automobile windows. It can also be used for heat rays.
Claims (14)
The silver conductive film according to claim 9, wherein an average particle diameter (D TEM ) of the silver particles is 20 nm or less.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2007005922A JP5081454B2 (en) | 2007-01-15 | 2007-01-15 | Silver conductive film and manufacturing method thereof |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2007005922A JP5081454B2 (en) | 2007-01-15 | 2007-01-15 | Silver conductive film and manufacturing method thereof |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JP2008171760A true JP2008171760A (en) | 2008-07-24 |
| JP5081454B2 JP5081454B2 (en) | 2012-11-28 |
Family
ID=39699644
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP2007005922A Expired - Fee Related JP5081454B2 (en) | 2007-01-15 | 2007-01-15 | Silver conductive film and manufacturing method thereof |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JP5081454B2 (en) |
Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2001077511A (en) * | 1999-09-07 | 2001-03-23 | Sumitomo Metal Electronics Devices Inc | Manufacture of ceramic board |
| JP2002150856A (en) * | 2000-11-07 | 2002-05-24 | Matsushita Electric Ind Co Ltd | Manufacturing method of electrode |
| JP2006185780A (en) * | 2004-12-28 | 2006-07-13 | Mitsuboshi Belting Ltd | Manufacturing method of silver thin film |
| JP2006286338A (en) * | 2005-03-31 | 2006-10-19 | Mitsuboshi Belting Ltd | Manufacturing method of silver-palladium alloy thin film |
| JP2006332051A (en) * | 2005-05-23 | 2006-12-07 | Samsung Electro-Mechanics Co Ltd | Conductive ink, preparation method thereof and conductive board |
-
2007
- 2007-01-15 JP JP2007005922A patent/JP5081454B2/en not_active Expired - Fee Related
Patent Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2001077511A (en) * | 1999-09-07 | 2001-03-23 | Sumitomo Metal Electronics Devices Inc | Manufacture of ceramic board |
| JP2002150856A (en) * | 2000-11-07 | 2002-05-24 | Matsushita Electric Ind Co Ltd | Manufacturing method of electrode |
| JP2006185780A (en) * | 2004-12-28 | 2006-07-13 | Mitsuboshi Belting Ltd | Manufacturing method of silver thin film |
| JP2006286338A (en) * | 2005-03-31 | 2006-10-19 | Mitsuboshi Belting Ltd | Manufacturing method of silver-palladium alloy thin film |
| JP2006332051A (en) * | 2005-05-23 | 2006-12-07 | Samsung Electro-Mechanics Co Ltd | Conductive ink, preparation method thereof and conductive board |
Also Published As
| Publication number | Publication date |
|---|---|
| JP5081454B2 (en) | 2012-11-28 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| JP5139659B2 (en) | Silver particle composite powder and method for producing the same | |
| JP5164239B2 (en) | Silver particle powder, dispersion thereof, and method for producing silver fired film | |
| JP4756163B2 (en) | Dispersion and paste of composite particle powder and method for producing silver particle powder used therefor | |
| EP2233230B1 (en) | Silver micropowder, silver ink, silver coating, and methods for production of these materials | |
| JP5557005B2 (en) | Conductive paste composition and method for producing the same | |
| JP2016526076A (en) | Printing ink containing silicon / germanium nanoparticles and a high viscosity alcohol solvent | |
| JP6782409B2 (en) | Capacitors and their manufacturing methods | |
| TW201610005A (en) | Method for manufacturing core-shell type metal fine particle, core-shell type metal fine particle, conductive ink, and method for manufacturing substrate | |
| JP6136622B2 (en) | Aqueous coating liquid for transparent conductive film and transparent conductive film using the same | |
| JP5191663B2 (en) | Manufacturing method of silver conductive film | |
| JP5005362B2 (en) | Silver particle dispersion and method for producing the same | |
| JP6414085B2 (en) | Method for producing metal nanoparticles | |
| TW201044463A (en) | Transparent conductive film encapsulating mesh-like structure formed from metal microparticles, substrate on which transparent conductive film is laminated, and method for producing the same | |
| JP5081454B2 (en) | Silver conductive film and manufacturing method thereof | |
| WO2014061750A1 (en) | Dispersant, metal particle dispersion for conductive substrate, and production method for conductive substrate | |
| JP5124822B2 (en) | Method for producing composite metal powder and dispersion thereof | |
| Rivkin et al. | Copper and silver inks for ink jet printing | |
| JP5226293B2 (en) | Method for producing silver conductive film | |
| JP6053725B2 (en) | Copper-based nanoparticle dispersion, method for producing the same, and substrate on which a copper conductor film produced from the dispersion is formed | |
| JP2010287434A (en) | Substrate with silver conductive film and method for manufacturing same |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| A621 | Written request for application examination |
Free format text: JAPANESE INTERMEDIATE CODE: A621 Effective date: 20091116 |
|
| A977 | Report on retrieval |
Free format text: JAPANESE INTERMEDIATE CODE: A971007 Effective date: 20120801 |
|
| TRDD | Decision of grant or rejection written | ||
| A01 | Written decision to grant a patent or to grant a registration (utility model) |
Free format text: JAPANESE INTERMEDIATE CODE: A01 Effective date: 20120828 |
|
| A01 | Written decision to grant a patent or to grant a registration (utility model) |
Free format text: JAPANESE INTERMEDIATE CODE: A01 |
|
| A61 | First payment of annual fees (during grant procedure) |
Free format text: JAPANESE INTERMEDIATE CODE: A61 Effective date: 20120903 |
|
| FPAY | Renewal fee payment (event date is renewal date of database) |
Free format text: PAYMENT UNTIL: 20150907 Year of fee payment: 3 |
|
| R150 | Certificate of patent or registration of utility model |
Ref document number: 5081454 Country of ref document: JP Free format text: JAPANESE INTERMEDIATE CODE: R150 Free format text: JAPANESE INTERMEDIATE CODE: R150 |
|
| R250 | Receipt of annual fees |
Free format text: JAPANESE INTERMEDIATE CODE: R250 |
|
| R250 | Receipt of annual fees |
Free format text: JAPANESE INTERMEDIATE CODE: R250 |
|
| R250 | Receipt of annual fees |
Free format text: JAPANESE INTERMEDIATE CODE: R250 |
|
| R250 | Receipt of annual fees |
Free format text: JAPANESE INTERMEDIATE CODE: R250 |
|
| R250 | Receipt of annual fees |
Free format text: JAPANESE INTERMEDIATE CODE: R250 |
|
| R250 | Receipt of annual fees |
Free format text: JAPANESE INTERMEDIATE CODE: R250 |
|
| LAPS | Cancellation because of no payment of annual fees |