JP5887086B2 - Conductive material - Google Patents
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- JP5887086B2 JP5887086B2 JP2011176176A JP2011176176A JP5887086B2 JP 5887086 B2 JP5887086 B2 JP 5887086B2 JP 2011176176 A JP2011176176 A JP 2011176176A JP 2011176176 A JP2011176176 A JP 2011176176A JP 5887086 B2 JP5887086 B2 JP 5887086B2
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本発明は、金属ナノ粒子と該金属ナノ粒子よりも平均一次粒子径が大きい金属粒子とを含有した金属粉が配合された導電性材料、より詳細には、スクリーン印刷法やインクジェット印刷法などを用いた塗工により、低温の熱処理にて基板上に電極と配線パターンを形成でき、また低温の熱処理で基板上に電子部品を接合できる導電性材料に関するものである。 The present invention relates to a conductive material in which a metal powder containing metal nanoparticles and metal particles having an average primary particle size larger than that of the metal nanoparticles is blended, more specifically, a screen printing method or an ink jet printing method. The present invention relates to a conductive material that can form electrodes and wiring patterns on a substrate by low-temperature heat treatment, and can bond electronic components on the substrate by low-temperature heat treatment.
近年、基板に電子部品を実装する分野において、電気的接合は、鉛フリーはんだ、例えば、スズ‐銀系、スズ‐銅系、スズ-銀-銅系のはんだが主流となっている。しかし、鉛フリーはんだは高融点であり、実装温度が２５０℃以上と高くなる。よって、電子部品や基板が熱損傷を起こすことがあり、全ての電子部品や基板に対応できるものではない。そこで、ＰＥＴなど耐熱性に劣った基板を用いる場合やモジュールの耐熱性の問題等で低温にて接合せざるを得ない場合には、比較的低温で電気的接合が可能なビスマスやインジウム系合金を使用していた。しかし、ビスマスは接合強度や合金の脆さに問題があり、インジウム系合金は高価という問題がある。 In recent years, in the field of mounting electronic components on a substrate, lead-free solder, for example, tin-silver solder, tin-copper solder, tin-silver-copper solder, has become the mainstream. However, lead-free solder has a high melting point, and the mounting temperature is as high as 250 ° C. or higher. Therefore, the electronic component or the substrate may be thermally damaged, and it cannot be applied to all the electronic components and the substrate. Therefore, when using a substrate with poor heat resistance, such as PET, or when it must be bonded at a low temperature due to the heat resistance problem of the module, etc., bismuth and indium alloys that can be electrically bonded at a relatively low temperature Was used. However, bismuth has a problem in bonding strength and alloy brittleness, and an indium alloy has a problem in that it is expensive.
基板と電子部品との接合強度を高めるために、融点の異なるはんだ粉末を配合して低融点のはんだ粉末が溶融することで高融点のはんだ粉末を連結させるはんだペーストが提案されている（特許文献１）。また、微細ピッチとはんだ付け後に発生する残渣の低減を両立させるために、平均粒子径の異なる２種以上のはんだ粒子を含むはんだペーストが提案されている（特許文献２）。さらに、はんだ付け後のはんだ組成を微細化して接合強度を向上させるために、はんだ粉末表面に５〜３００ｎｍの所定のナノ粒子を配置したはんだ粉末とフラックスを混練したはんだペーストが提案されている（特許文献３）。 In order to increase the bonding strength between a substrate and an electronic component, a solder paste has been proposed in which solder powders having different melting points are blended and the low melting point solder powders are melted to connect the high melting point solder powders (Patent Documents). 1). In order to achieve both the fine pitch and the reduction of residues generated after soldering, a solder paste containing two or more kinds of solder particles having different average particle diameters has been proposed (Patent Document 2). Furthermore, in order to refine the solder composition after soldering and improve the bonding strength, a solder paste is proposed in which a solder powder in which predetermined nanoparticles of 5 to 300 nm are arranged on the surface of the solder powder and a flux are kneaded ( Patent Document 3).
しかし、上記特許文献１〜３では、いずれも、依然として、はんだ粉末の融点が高く、電子部品や基板が熱損傷を起こやすいという問題、また、はんだペーストにフラックスを配合するので、はんだ付け後にフラックス残渣が発生し、環境に負荷がかかるという問題がある。 However, in all of the above Patent Documents 1 to 3, the melting point of the solder powder is still high and the electronic component and the substrate are easily damaged by heat, and the flux is mixed with the solder paste. There is a problem that residue is generated and the environment is loaded.
一方で、耐熱性の点ではんだ付けに不向きな電子部品の実装やモジュールの組み立てには、比較的低温で電気的接合が可能な銀ペーストが用いられ、導通抵抗の上昇を防止するために、銀ペーストに低融点金属や導電フィラー、金属ナノ粒子を添加することが行なわれている。金属ナノ粒子は、比表面積が大きく反応活性が高いので、金属バルクと比較して、低温で融着する低温焼結という特性を有する。例えば、銀ナノ粒子の場合、本来の融点９６４℃より格段に低い２００℃程度の加熱処理で融着接合現象が起こり、金属バルクと同等程度の導通性を示すことが知られているが、依然として、導電性、接合強度が不十分であるという問題がある。 On the other hand, silver paste that can be electrically joined at a relatively low temperature is used for mounting electronic components and modules that are unsuitable for soldering in terms of heat resistance, in order to prevent an increase in conduction resistance. Addition of a low melting point metal, a conductive filler, or metal nanoparticles to the silver paste is performed. Since metal nanoparticles have a large specific surface area and high reaction activity, they have the characteristic of low-temperature sintering that fuses at a low temperature compared to metal bulk. For example, in the case of silver nanoparticles, it is known that a fusion-bonding phenomenon occurs in a heat treatment at about 200 ° C., which is much lower than the original melting point of 964 ° C., and exhibits a conductivity comparable to that of a metal bulk. There is a problem that conductivity and bonding strength are insufficient.
本発明は、上記事情に鑑み、金属ナノ粒子の低温焼結特性を用いて、導電性及び機械的特性に優れた金属接合を得ることができる導電性材料、良導電性を有する配線パターンを形成できる導電性材料を提供することを目的とする。 In view of the above circumstances, the present invention uses a low-temperature sintering property of metal nanoparticles to form a conductive material capable of obtaining a metal bond excellent in conductivity and mechanical properties, and a wiring pattern having good conductivity. An object of the present invention is to provide a conductive material that can be used.
本発明の態様は、（Ａ）平均一次粒子径が１〜１００ｎｍの金属ナノ粒子と（Ｂ）平均一次粒子径が１〜１００μｍの第２の金属粒子とを含有した金属粉が、配合されていることを特徴とする導電性材料である。本発明の導電性材料で用いられている金属粉の構成成分は、第１の金属粒子である金属ナノ粒子と該金属ナノ粒子よりも平均一次粒子径が大きい第２の金属粒子である。「金属ナノ粒子」とは、平均一次粒子径がナノオーダー、すなわち１ｎｍ以上１μｍ未満の金属粒子であり、本発明では、平均一次粒子径が１〜１００ｎｍの金属粒子を用いている。また、本明細書では、「第２の金属粒子」とは、平均一次粒子径がマイクロオーダー、すなわち１μｍ以上１ｍｍ未満の金属粒子を意味しており、本発明では、平均一次粒子径が１〜１００μｍの金属粒子を用いている。本発明の態様では、フラックスは含まれていない。 In an aspect of the present invention, a metal powder containing (A) metal nanoparticles having an average primary particle diameter of 1 to 100 nm and (B) second metal particles having an average primary particle diameter of 1 to 100 μm is blended. It is the electroconductive material characterized by having. The constituent components of the metal powder used in the conductive material of the present invention are the metal nanoparticles that are the first metal particles and the second metal particles having an average primary particle size larger than that of the metal nanoparticles. The “metal nanoparticles” are metal particles having an average primary particle diameter of nano-order, that is, 1 nm or more and less than 1 μm. In the present invention, metal particles having an average primary particle diameter of 1 to 100 nm are used. In the present specification, the “second metal particle” means a metal particle having an average primary particle diameter of micro order, that is, 1 μm or more and less than 1 mm. In the present invention, the average primary particle diameter is 1 to 1 mm. 100 μm metal particles are used. In embodiments of the present invention, no flux is included.
平均一次粒子径が１〜１００ｎｍの金属ナノ粒子と平均一次粒子径が１〜１００μｍの第２の金属粒子とを含有した金属粉を、金属ナノ粒子の融点よりも低い所定の温度で加熱処理、すなわち低温焼結させると、第２の金属粒子間に生じる隙間に金属ナノ粒子が入った状態で金属ナノ粒子が低温焼結する。これにより、第２の金属粒子間に生じる隙間が低温焼結した金属ナノ粒子によって埋められて、ボイド（空泡）の発生が防止される。また、上記の通り、第２の金属粒子の平均一次粒子径は金属ナノ粒子の平均一次粒子径よりも大きい。従って、後述するように、第２の金属粒子を有機保護膜で被覆しても、低温焼結時に発生する第２の金属粒子単位量当りの有機保護膜由来の気体量は、有機保護膜で被覆した金属ナノ粒子の、低温焼結時に発生する金属ナノ粒子単位量当りの有機保護膜由来の気体量よりも少なくなる。上記気体発生量の差の点でも、金属ナノ粒子と第２の金属粒子とを含有した金属粉を用いることで、ボイド（空泡）の発生が防止される。また、第２の金属粒子同士は、低温焼結した金属ナノ粒子を介して接合される。 Heat-treating a metal powder containing metal nanoparticles having an average primary particle diameter of 1 to 100 nm and second metal particles having an average primary particle diameter of 1 to 100 μm at a predetermined temperature lower than the melting point of the metal nanoparticles, That is, when low-temperature sintering is performed, the metal nanoparticles are sintered at a low temperature in a state where the metal nanoparticles are contained in the gap formed between the second metal particles. Thereby, the gap generated between the second metal particles is filled with the metal nanoparticles sintered at low temperature, and the generation of voids (air bubbles) is prevented. Moreover, as above-mentioned, the average primary particle diameter of a 2nd metal particle is larger than the average primary particle diameter of a metal nanoparticle. Therefore, as will be described later, even if the second metal particles are coated with an organic protective film, the amount of gas derived from the organic protective film per unit amount of the second metal particles generated during low-temperature sintering is the organic protective film. The amount of the coated metal nanoparticles is less than the amount of gas derived from the organic protective film per unit amount of metal nanoparticles generated during low-temperature sintering. Also in terms of the difference in the amount of gas generated, the use of metal powder containing metal nanoparticles and second metal particles prevents the generation of voids (air bubbles). Further, the second metal particles are joined to each other through the low-temperature sintered metal nanoparticles.
一方で、第２の金属粒子を含まない金属ナノ粒子からなる金属粉を低温焼結させると、金属ナノ粒子の表面を被覆している有機保護膜が加熱時に揮発して消失することから、金属ナノ粒子の分散が不均一な状態で焼結する。その結果、焼結体が金属の網目状構造となってしまうので、ボイド（空泡）が多く発生すると考えられる。また、金属ナノ粒子を含まない第２の金属粒子からなる金属粉では、低温焼結が生じないので、金属固有の融点まで温度を挙げて加熱処理をする必要が生じる。 On the other hand, when the metal powder composed of metal nanoparticles not containing the second metal particles is sintered at low temperature, the organic protective film covering the surface of the metal nanoparticles volatilizes and disappears upon heating. Sintering in a non-uniform dispersion of nanoparticles. As a result, since the sintered body has a metal network structure, it is considered that many voids (air bubbles) are generated. Moreover, in the metal powder which consists of the 2nd metal particle which does not contain a metal nanoparticle, since low temperature sintering does not arise, it is necessary to heat-process up to melting | fusing point intrinsic | native to a metal.
なお、「低温焼結」とは、金属ナノ粒子を構成する金属の固有の融点よりも低い温度で、金属ナノ粒子が相互に融着して焼結することを意味する。本明細書では、「平均一次粒子径」とは、金属ナノ粒子、第２の金属粒子の凝集前の粒子径のことであり、良分散溶媒中で、超音波等により分散後レーザー式粒度分布計により測定された値を意味する。 “Low-temperature sintering” means that metal nanoparticles are fused and sintered at a temperature lower than the inherent melting point of the metal constituting the metal nanoparticles. In the present specification, the “average primary particle size” is the particle size before aggregation of the metal nanoparticles and the second metal particles, and after dispersion in a well-dispersed solvent by ultrasonic waves, etc. It means the value measured by the meter.
本発明の態様は、前記金属粉が、１〜３０質量％の前記（Ａ）金属ナノ粒子を含有することを特徴とする導電性材料である。 An aspect of the present invention is the conductive material, wherein the metal powder contains 1 to 30% by mass of the (A) metal nanoparticles.
本発明の態様は、前記（Ａ）金属ナノ粒子が、銀ナノ粒子を含有することを特徴とする導電性材料である。この態様では、金属ナノ粒子の金属種には、少なくとも銀が含まれる。 An aspect of the present invention is a conductive material in which the metal nanoparticles (A) contain silver nanoparticles. In this embodiment, the metal species of the metal nanoparticles include at least silver.
本発明の態様は、前記（Ｂ）第２の金属粒子が、銀、銅、銀合金、銅合金及び銀で被覆された銅からなる群から選択された少なくとも１種であることを特徴とする導電性材料である。 An aspect of the present invention is characterized in that the (B) second metal particle is at least one selected from the group consisting of silver, copper, a silver alloy, a copper alloy, and copper coated with silver. It is a conductive material.
本発明の態様は、前記（Ｂ）第２の金属粒子が、有機保護膜で被覆されていることを特徴とする導電性材料である。本発明の態様は、前記有機保護膜が、イミダゾール及び／またはフェニル基を有するイミダゾール誘導体を含むことを特徴とする導電性材料である。 An aspect of the present invention is the conductive material, wherein the (B) second metal particles are covered with an organic protective film. An aspect of the present invention is the conductive material, wherein the organic protective film includes an imidazole derivative having an imidazole and / or a phenyl group.
本発明の態様は、さらに、（Ｃ）溶剤が配合されていることを特徴とする導電性材料である。溶剤は、導電性材料の粘度調整のために配合する。 An aspect of the present invention is a conductive material characterized in that a solvent (C) is further blended. The solvent is blended for adjusting the viscosity of the conductive material.
本発明の態様は、上記導電性材料を用いて、基板に電子部品を実装したことを特徴とする電子部品接合体である。また、本発明の態様は、前記電子部品が、LED素子であることを特徴とする電子部品接合体である。 An aspect of the present invention is an electronic component joined body in which an electronic component is mounted on a substrate using the conductive material. According to another aspect of the present invention, there is provided an electronic component assembly in which the electronic component is an LED element.
本発明の態様は、回路形成用基板上に、上記導電性材料を塗工して、電極及び配線パターンを形成する工程と、前記塗工した回路形成用基板を、１８０〜２３０℃で加熱して、前記電極及び配線パターンを焼成処理する工程と、を備えることを特徴とする回路形成方法である。 An aspect of the present invention includes a step of coating the conductive material on a circuit forming substrate to form an electrode and a wiring pattern, and heating the coated circuit forming substrate at 180 to 230 ° C. And a step of baking the electrodes and the wiring pattern.
本発明によれば、平均一次粒子径１〜１００ｎｍの金属ナノ粒子と平均一次粒子径１〜１００μｍの第２の金属粒子とを含有した金属粉は、ボイドの発生を抑制するので、金属ナノ粒子のみを用いた金属接合よりも、導電性と機械的強度に優れた金属接合が得られる。また、金属ナノ粒子のみを用いた配線パターンよりも、導電性に優れた配線パターンが形成できる。さらに、金属ナノ粒子の低温焼結特性を用いるので、低い熱処理温度にて金属接合や配線パターンを形成でき、金属接合の対象である電子部品や基板等の熱による損傷を防止できる。さらに、導電性材料にはフラックスが含まれていないので、環境負荷を低減できる。 According to the present invention, the metal powder containing metal nanoparticles having an average primary particle diameter of 1 to 100 nm and second metal particles having an average primary particle diameter of 1 to 100 μm suppresses the generation of voids. Compared to metal bonding using only the metal bonding, metal bonding excellent in conductivity and mechanical strength can be obtained. Moreover, the wiring pattern excellent in electroconductivity can be formed rather than the wiring pattern using only metal nanoparticles. Furthermore, since the low-temperature sintering characteristics of the metal nanoparticles are used, metal bonding and wiring patterns can be formed at a low heat treatment temperature, and damage to the electronic components and substrates that are the objects of metal bonding can be prevented. Furthermore, since the conductive material contains no flux, the environmental load can be reduced.
本発明によれば、金属粉が１〜３０質量％の金属ナノ粒子を含有することで、導電性と機械的強度がバランスよく向上する。 According to this invention, electroconductivity and mechanical strength improve with a good balance because a metal powder contains 1-30 mass% metal nanoparticles.
本発明によれば、第２の金属粒子が有機物の保護膜で被覆されていることで、導電性材料の保存期間中、第２の金属粒子の酸化が防止されるので、導電性を損なうことなく、金属結合の機械的強度がより向上する。 According to the present invention, since the second metal particles are covered with an organic protective film, the second metal particles are prevented from being oxidized during the storage period of the conductive material, so that the conductivity is impaired. And the mechanical strength of the metal bond is further improved.
次に、本発明の導電性材料について説明する。本発明の導電性材料は、（Ａ）平均一次粒子径が１〜１００ｎｍの金属ナノ粒子と（Ｂ）平均一次粒子径が１〜１００μｍの第２の金属粒子とを含有した金属粉が、配合されている。 Next, the conductive material of the present invention will be described. The conductive material of the present invention is composed of (A) metal nanoparticles having an average primary particle diameter of 1 to 100 nm and (B) second metal particles having an average primary particle diameter of 1 to 100 μm. Has been.
（Ａ）金属ナノ粒子
（Ａ）成分である金属ナノ粒子は、ナノオーダーの平均一次粒子径を有する金属粒子である。ナノオーダーの平均一次粒子径を有することで、比表面積が大きく粒子表面の反応活性が高くなるので、金属本来の融点よりもはるかに低い加熱温度で、電子部品を基板に電気的に接合でき、また基板上に配線パターンを形成できる。金属ナノ粒子の金属種は、良導電性を有するものであれば特に限定されず、例えば、金、銀、銅、白金、パラジウム、ニッケル、ビスマス、鉛、インジウム、スズ、亜鉛、チタン、アルミニウム及びアンチモンなど、はんだに使用される金属単体や上記金属種を含有する金属合金を挙げることができる。上記金属種のうち、優れた導電性と熱伝導性を有する点から銀、銅が好ましい。
(A) Metal nanoparticle The metal nanoparticle which is (A) component is a metal particle which has an average primary particle diameter of nano order. By having a nano-order average primary particle size, the specific surface area is large and the reaction activity of the particle surface is high, so that the electronic component can be electrically bonded to the substrate at a heating temperature much lower than the original melting point of the metal, A wiring pattern can be formed on the substrate. The metal species of the metal nanoparticles are not particularly limited as long as they have good conductivity. For example, gold, silver, copper, platinum, palladium, nickel, bismuth, lead, indium, tin, zinc, titanium, aluminum and Examples thereof include a simple metal used for solder such as antimony and a metal alloy containing the above metal species. Among the above metal species, silver and copper are preferable from the viewpoint of having excellent conductivity and thermal conductivity.
金属ナノ粒子の平均一次粒子径の上限値は適宜選択可能であるが、低温焼結性を奏する点から１００ｎｍであり、ボイドの発生を確実に防止する点から５０ｎｍが好ましく、緻密な電子部品接合部への適用及び微細な配線パターンの形成の点から２０ｎｍ、低温焼結性を確実に発揮する点から１０ｎｍが特に好ましい。また、金属ナノ粒子の平均一次粒子径の下限値は適宜選択可能であるが、金属ナノ粒子の被覆処理等の加工性の点から２ｎｍであり、第２の金属粒子との混合性及び導電性材料の生産安定性の点から５ｎｍが好ましく、上記混合性と生産安定性をより向上させる点から７ｎｍが特に好ましい。これらの金属ナノ粒子は単独で使用してもよく、２種以上を混合して使用してもよい。 The upper limit of the average primary particle diameter of the metal nanoparticles can be selected as appropriate, but it is 100 nm from the viewpoint of low-temperature sinterability, and 50 nm is preferable from the viewpoint of surely preventing the generation of voids. 20 nm is particularly preferable from the viewpoint of application to a part and formation of a fine wiring pattern, and 10 nm is particularly preferable from the viewpoint of reliably exhibiting low-temperature sinterability. The lower limit of the average primary particle diameter of the metal nanoparticles can be selected as appropriate, but it is 2 nm from the viewpoint of processability such as coating treatment of the metal nanoparticles, and the mixing property and conductivity with the second metal particles. 5 nm is preferable from the viewpoint of the production stability of the material, and 7 nm is particularly preferable from the viewpoint of further improving the mixing property and the production stability. These metal nanoparticles may be used alone or in combination of two or more.
金属ナノ粒子は表面の反応活性が高いので、凝集し易く、その結果、分散安定性が損なわれることがある。これを防止するために、金属ナノ粒子の表面を有機保護膜で被覆してもよい。前記保護膜の構成成分は、金属ナノ粒子表面を被覆して、金属ナノ粒子の凝集を防止できる化合物であれば特に限定されず、例えば、金属ナノ粒子と孤立電子対による配位的な結合が可能である、酸素原子、窒素原子または硫黄原子を含んだ基を有する有機化合物を挙げることができる。上記した酸素原子、窒素原子または硫黄原子が静電力に起因した分子間力によって金属ナノ粒子表面に結合することにより、保護膜が金属ナノ粒子を被覆する。酸素原子を含んだ基の例としてヒドロキシ基（-OH）やオキシ基（-O-）、カルボニル基（＝O）、カルボキシル基（＝COOH）、窒素原子を含んだ基の例としてアミノ基（-NH2）、硫黄原子を含んだ基の例としてスルファニル基（-SH）を挙げることができる。 Since the metal nanoparticles have high surface reaction activity, they tend to aggregate, and as a result, dispersion stability may be impaired. In order to prevent this, the surface of the metal nanoparticles may be covered with an organic protective film. The component of the protective film is not particularly limited as long as it is a compound that covers the surface of the metal nanoparticle and prevents aggregation of the metal nanoparticle. For example, a coordinate bond between the metal nanoparticle and the lone electron pair is formed. Mention may be made of organic compounds having groups containing oxygen, nitrogen or sulfur atoms. The above-described oxygen atom, nitrogen atom, or sulfur atom is bonded to the surface of the metal nanoparticle by intermolecular force due to electrostatic force, so that the protective film covers the metal nanoparticle. Examples of groups containing oxygen atoms include hydroxy groups (—OH), oxy groups (—O—), carbonyl groups (═O), carboxyl groups (═COOH), and groups containing nitrogen atoms such as amino groups ( As an example of a group containing —NH 2 ) or a sulfur atom, a sulfanyl group (—SH) can be mentioned.
保護膜で被覆された金属ナノ粒子の製造方法は、特に限定されないが、例えば、特開平３‐３４２１１号公報に記載のガス中蒸発法や特開２００８−１５０６３０号公報に記載の活性連続界面蒸着法等の物理的手法、特開２００９−１２０９４９号公報や特開２００５−０３６３０９号公報等に記載の銀塩を還元剤によって還元する化学的手法が挙げられる。 The method for producing the metal nanoparticles coated with the protective film is not particularly limited. For example, the gas evaporation method described in JP-A-3-34211 and the active continuous interface deposition described in JP-A-2008-150630 And a physical method such as a chemical method, and a chemical method of reducing a silver salt described in JP-A-2009-120949, JP-A-2005-036309, or the like with a reducing agent.
（Ｂ）第２の金属粒子
（Ｂ）成分である第２の金属粒子は、マイクロオーダーの平均一次粒子径を有する金属粒子である。上記金属ナノ粒子に第２の金属粒子を配合すると、第２の金属粒子間に生じる隙間に金属ナノ粒子が入った状態で金属ナノ粒子が低温焼結する。その結果、第２の金属粒子間の隙間が低温焼結した金属ナノ粒子によって埋められてボイド（空泡）の発生が防止される。また、第２の金属粒子間に入り込んだ金属ナノ粒子が低温焼結することにより、第２の金属粒子同士は低温焼結した金属ナノ粒子を介して接合する。これにより、金属粉として金属ナノ粒子のみを用いた導電性材料と比較して、金属接合の強度と導電性及び配線パターンの導電性がより一層向上する。第２の金属粒子の金属種は、良導電性を有するものであれば特に限定されず、例えば、金、銀、銅、白金、パラジウム、ニッケル、ビスマス、鉛、インジウム、スズ、亜鉛、チタン、アルミニウム及びアンチモンなど、はんだに使用される金属単体や上記金属種を含有する金属合金を挙げることができる。上記金属種のうち、優れた導電性と熱伝導性を有する点から銀、銅が好ましく、金属接合の強度と導電性ともにより優れている点から銀が特に好ましい。
(B) 2nd metal particle The 2nd metal particle which is (B) component is a metal particle which has an average primary particle diameter of a micro order. When the second metal particles are blended with the metal nanoparticles, the metal nanoparticles are sintered at a low temperature in a state where the metal nanoparticles are contained in the gap generated between the second metal particles. As a result, the gaps between the second metal particles are filled with the metal nanoparticles that have been sintered at a low temperature, thereby preventing the generation of voids (air bubbles). Moreover, when the metal nanoparticles that have entered between the second metal particles are sintered at a low temperature, the second metal particles are bonded to each other through the low-temperature sintered metal nanoparticles. Thereby, compared with the electroconductive material which used only the metal nanoparticle as metal powder, the intensity | strength and electroconductivity of metal joining, and the electroconductivity of a wiring pattern improve further. The metal species of the second metal particle is not particularly limited as long as it has good conductivity. For example, gold, silver, copper, platinum, palladium, nickel, bismuth, lead, indium, tin, zinc, titanium, Examples thereof include simple metals used for solder, such as aluminum and antimony, and metal alloys containing the above metal species. Among the above metal species, silver and copper are preferable from the viewpoint of having excellent conductivity and thermal conductivity, and silver is particularly preferable from the viewpoint that both the strength and conductivity of metal bonding are excellent.
第２の金属粒子の平均一次粒子径の上限値は、第２の金属粒子間の接着性の点から１００μｍであり、接合材料として使用する場合の接合部の面積とピッチサイズの点から５０μｍが好ましく、より微細な領域への供給を可能にする点から２０μｍが特に好ましい。また、第２の金属粒子の平均一次粒子径の下限値は、第２の金属粒子の凝集を防止する点から１μｍであり、密な金属接合を形成する点から２μｍが好ましく、有機保護膜の総量を抑えることでボイドの低減した密な金属接合を確実に形成する点から３μｍが特に好ましい。これらの第２の金属粒子は単独で使用してもよく、２種以上を混合して使用してもよい。 The upper limit of the average primary particle diameter of the second metal particles is 100 μm from the viewpoint of adhesion between the second metal particles, and 50 μm from the viewpoint of the area and pitch size of the joint when used as a joining material. 20 μm is particularly preferable from the viewpoint of enabling supply to a finer region. The lower limit of the average primary particle diameter of the second metal particles is 1 μm from the viewpoint of preventing aggregation of the second metal particles, and preferably 2 μm from the viewpoint of forming a dense metal bond. 3 μm is particularly preferable from the viewpoint of reliably forming a dense metal joint with reduced voids by suppressing the total amount. These 2nd metal particles may be used independently, and 2 or more types may be mixed and used for them.
第２の金属粒子は、その表面が有機物の保護膜で被覆処理された態様としてもよい。第２の金属粒子の表面を被覆する有機物の保護膜により、保存時における第２の金属粒子の酸化が防止される。従って、上記保護膜により、導電性を損なうことなく金属接合の強度が向上する。第２の金属粒子の表面を被覆する有機物としては、例えば、第２の金属粒子と孤立電子対による配位的な結合が可能である窒素原子を含んだ基を有する有機物を挙げることができる。具体的には、イミダゾール、フェニル基を有するイミダゾール誘導体が挙げられる。フェニル基を有するイミダゾール誘導体には、例えば、下記一般式で表されるイミダゾール化合物が挙げられる。 The second metal particles may have a surface coated with an organic protective film. The organic protective film covering the surface of the second metal particles prevents oxidation of the second metal particles during storage. Therefore, the protective film improves the strength of metal bonding without impairing conductivity. As an organic substance which coat | covers the surface of a 2nd metal particle, the organic substance which has the group containing the nitrogen atom which can be coordinated by the 2nd metal particle and a lone electron pair can be mentioned, for example. Specific examples include imidazole and imidazole derivatives having a phenyl group. Examples of the imidazole derivative having a phenyl group include imidazole compounds represented by the following general formula.
（式中、Ｒ１は、水素、炭素数１〜１１の直鎖又は分岐鎖のアルキル基を表す。Ｒ２は、互いに独立して、炭素数１〜１１の直鎖又は分岐鎖のアルコキシ基を表す。Ｒ３は、互いに独立して、炭素数１〜１１の直鎖又は分岐鎖のアルキル基、塩素または臭素を表す。ｍは１〜４の整数、ｎは０〜４の整数である。） (In the formula, R 1 represents hydrogen or a linear or branched alkyl group having 1 to 11 carbon atoms. R 2 independently represents a linear or branched alkoxy group having 1 to 11 carbon atoms. R 3 represents, independently of each other, a linear or branched alkyl group having 1 to 11 carbon atoms, chlorine or bromine, m is an integer of 1 to 4, and n is an integer of 0 to 4. .)
具体的には、２−フェニル−４−（２−メトキシ）フェニルイミダゾール、２−フェニル−４−（３−メトキシ）フェニルイミダゾール、２−フェニル−４−（３−エトキシ）フェニルイミダゾール、２−フェニル−４−（３，４−ジメトキシ）フェニルイミダゾール、２−フェニル−４−（３，４−ジメトキシ）フェニル−５−メチルイミダゾール、２−フェニル−４−（２−メトキシ−５−メチル）フェニルイミダゾール、２−フェニル−４−（２−クロロ−５−メトキシ）フェニルイミダゾール、２−フェニル−４−（２、５−ジメトキシ−３−メチル）フェニルイミダゾール、２−フェニル−４−（２、３、５−トリメトキシ−６−メチル）フェニルイミダゾール等が挙げられる。 Specifically, 2-phenyl-4- (2-methoxy) phenylimidazole, 2-phenyl-4- (3-methoxy) phenylimidazole, 2-phenyl-4- (3-ethoxy) phenylimidazole, 2-phenyl -4- (3,4-dimethoxy) phenylimidazole, 2-phenyl-4- (3,4-dimethoxy) phenyl-5-methylimidazole, 2-phenyl-4- (2-methoxy-5-methyl) phenylimidazole 2-phenyl-4- (2-chloro-5-methoxy) phenylimidazole, 2-phenyl-4- (2,5-dimethoxy-3-methyl) phenylimidazole, 2-phenyl-4- (2,3, 5-trimethoxy-6-methyl) phenylimidazole and the like.
第２の金属粒子に対する上記有機物の被覆量は適宜選択可能であるが、その上限値は、第２の金属粒子１００質量部に対して、ボイドの発生を確実に抑制する点から１０質量部が好ましく、揮発する有機物成分を確実に低減して密な金属接合を形成する点から５質量部が特に好ましい。一方、その下限値は、第２の金属粒子１００質量部に対して、第２の金属粒子の酸化防止の点から１質量部が好ましく、確実に第２の金属粒子を被覆する点で３質量部が特に好ましい。これら有機物の保護膜の構成成分は単独で使用してもよく、２種以上を混合して使用してもよい。 The coating amount of the organic substance on the second metal particles can be selected as appropriate, but the upper limit is 10 parts by mass with respect to 100 parts by mass of the second metal particles from the viewpoint of reliably suppressing the generation of voids. Preferably, 5 parts by mass is particularly preferable from the viewpoint of reliably reducing the volatile organic component and forming a dense metal bond. On the other hand, the lower limit is preferably 1 part by mass with respect to 100 parts by mass of the second metal particles from the viewpoint of preventing oxidation of the second metal particles, and 3 masses in terms of reliably covering the second metal particles. Part is particularly preferred. These components of the organic protective film may be used alone or in combination of two or more.
第２の金属粒子の表面を有機物で被覆処理して有機物の保護膜を形成する方法は、特に限定されない。例えば、保護膜の構成成分である有機物を有機酸（例えば、ギ酸、酢酸、プロピオン酸、酪酸、吉草酸等）に溶解させた後、第２の金属粒子への有機物の保護膜形成を促進させる保護膜形成助剤である金属化合物（例えば、ギ酸銅、塩化第一銅、塩化第二銅、シュウ酸銅、酢酸銅、水酸化銅、酸化第一銅、酸化第二銅、炭酸銅、リン酸銅、硫酸銅、ギ酸マンガン、塩化マンガン、シュウ酸マンガン、硫酸マンガン、酢酸亜鉛、臭化亜鉛、水素化亜鉛、塩化鉄、酸化鉄、ヨウ化銅、臭化銅、臭化銅等）を溶解させる。次に、純水を加えてからアルカリでｐＨを調整して保護膜形成用処理液を調製する。この処理液に第２の金属粒子を所定温度（例えば３０〜５０℃）で所定時間（例えば、１〜３時間）浸漬、攪拌させた後、第２の金属粒子を取り出して、水洗、乾燥することで、有機物で被覆された第２の金属粒子を作成する方法が挙げられる。 The method of coating the surface of the second metal particles with an organic material to form an organic protective film is not particularly limited. For example, an organic substance that is a component of the protective film is dissolved in an organic acid (for example, formic acid, acetic acid, propionic acid, butyric acid, valeric acid, etc.), and then the formation of the protective film of the organic substance on the second metal particles is promoted. Metal compounds that are protective film formation aids (eg, copper formate, cuprous chloride, cupric chloride, copper oxalate, copper acetate, copper hydroxide, cuprous oxide, cupric oxide, copper carbonate, phosphorus Copper oxide, copper sulfate, manganese formate, manganese chloride, manganese oxalate, manganese sulfate, zinc acetate, zinc bromide, zinc hydride, iron chloride, iron oxide, copper iodide, copper bromide, copper bromide, etc.) Dissolve. Next, after adding pure water, the pH is adjusted with an alkali to prepare a protective film-forming treatment solution. The second metal particles are immersed and stirred in the treatment liquid at a predetermined temperature (for example, 30 to 50 ° C.) for a predetermined time (for example, 1 to 3 hours), and then the second metal particles are taken out, washed with water, and dried. By this, the method of creating the 2nd metal particle coat | covered with organic substance is mentioned.
また、第２の金属粒子に銀以外の金属種（例えば、銅）を使用する場合には、該金属種の表面に銀粉を被覆させた第２の金属粒子としてもよい。銀以外の金属種の第２の金属粒子表面を銀で被覆することにより、銀の第２の金属粒子を配合するよりも低コストで、銀の第２の金属粒子を配合した導電性材料と同様の特性を有する導電性材料、すなわち、金属接合の強度と導電性ともにより優れている導電性材料とすることができる。 Moreover, when using metal seed | species (for example, copper) other than silver for the 2nd metal particle, it is good also as the 2nd metal particle which coat | covered silver powder on the surface of this metal seed | species. By coating the surface of the second metal particles of a metal species other than silver with silver, the conductive material containing the second metal particles of silver is produced at a lower cost than that of adding the second metal particles of silver. A conductive material having similar characteristics, that is, a conductive material that is superior in both strength and conductivity of metal bonding can be obtained.
銀粉の被覆量は適宜選択可能であるが、その上限値は、第２の金属粒子１００質量部に対して、コスト低減の点から３０質量部が好ましく、２０質量部が特に好ましい。一方、その下限値は、第２の金属粒子１００質量部に対して、金属接合の強度と導電性を向上させる点から５質量部が好ましく、銀の特性を確実に発現させる点で１０質量部が特に好ましい。 The coating amount of silver powder can be selected as appropriate, but the upper limit is preferably 30 parts by mass, particularly preferably 20 parts by mass with respect to 100 parts by mass of the second metal particles. On the other hand, the lower limit is preferably 5 parts by mass with respect to 100 parts by mass of the second metal particles from the viewpoint of improving the strength and conductivity of metal bonding, and 10 parts by mass in terms of reliably expressing the characteristics of silver. Is particularly preferred.
上記した金属ナノ粒子と第２の金属粒子とを含有した金属粉中における金属ナノ粒子の配合割合の上限値は、ボイドの発生を抑える点から９０質量％であり、確実に金属接合の強度を向上させる点から８０質量％が好ましく、金属接合の強度と導電性をより向上させる点から３０質量％が特に好ましい。また、金属粉中における金属ナノ粒子の配合割合の下限値は、第２の金属粒子を相互に接合する点から０．１質量％であり、導電性材料の低温焼結性を確実に向上させる点から０．５質量％が好ましく、金属接合の強度と導電性をより向上させる点から１質量％が特に好ましい。 The upper limit of the mixing ratio of the metal nanoparticles in the metal powder containing the metal nanoparticles and the second metal particles is 90% by mass from the viewpoint of suppressing the generation of voids, and the strength of metal bonding is surely increased. 80 mass% is preferable from the point which improves, and 30 mass% is especially preferable from the point which improves the intensity | strength and electroconductivity of metal joining more. Moreover, the lower limit of the compounding ratio of the metal nanoparticles in the metal powder is 0.1% by mass from the point of joining the second metal particles to each other, and the low-temperature sinterability of the conductive material is reliably improved. 0.5 mass% is preferable from the point, and 1 mass% is particularly preferable from the viewpoint of further improving the strength and conductivity of metal bonding.
本発明では、必要に応じて、（Ｃ）分散媒を配合してもよい。分散媒を配合することで、導電性材料の粘度を調整して、例えばペースト状とすることで、導電性材料の塗工性を向上させることができる。また、溶媒は、低温焼結時に金属ナノ粒子が導電性材料ペースト中を移動する際の潤滑剤としても機能する。 In the present invention, (C) a dispersion medium may be blended as necessary. By blending the dispersion medium, the viscosity of the conductive material is adjusted, and for example, by making it into a paste, the coating property of the conductive material can be improved. The solvent also functions as a lubricant when the metal nanoparticles move through the conductive material paste during low-temperature sintering.
分散媒の例としては、デカン、テトラデカン、オクタデカン等の飽和または不飽和脂肪族炭化水素類、メチルエチルケトン、シクロヘキサノンなどのケトン類；トルエン、キシレン、テトラメチルベンゼンなどの芳香族炭化水素類；メチルセロソルブ、エチルセロソルブ、ブチルセロソルブ、メチルカルビトール、ブチルカルビトール、プロピレングリコールモノメチルエーテル、ジエチレングリコールモノメチルエーテル、ジエチレングリコールモノエチルエーテル、ジプロプレングリコールモノエチルエーテル、トリエチレングリコールモノエチルエーテルなどのグリコールエーテル類；酢酸エチル、酢酸ブチル、セロソルブアセテート、ジエチレングリコールモノメチルエーテルアセテート、ジエチレングリコールモノエチルエーテルアセテート、プロピレングリコールモノメチルエーテルアセテート及び上記グリコールエーテル類のエステル化物などのエステル類；エタノール、プロパノール、エチレングリコール、プロピレングリコール、ヘキシルジグリコール、テルピネオールなどのアルコール類、スクアランなど炭素数３０以上の不飽和炭化水素類等を挙げることができる。 Examples of the dispersion medium include saturated or unsaturated aliphatic hydrocarbons such as decane, tetradecane, and octadecane; ketones such as methyl ethyl ketone and cyclohexanone; aromatic hydrocarbons such as toluene, xylene, and tetramethylbenzene; methyl cellosolve; Glycol ethers such as ethyl cellosolve, butyl cellosolve, methyl carbitol, butyl carbitol, propylene glycol monomethyl ether, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, dipropylene glycol monoethyl ether, triethylene glycol monoethyl ether; ethyl acetate, acetic acid Butyl, cellosolve acetate, diethylene glycol monomethyl ether acetate, diethylene glycol monoethyl ether Esters such as cetate, propylene glycol monomethyl ether acetate and esterified products of the above glycol ethers; alcohols such as ethanol, propanol, ethylene glycol, propylene glycol, hexyl diglycol and terpineol, and unsaturated carbonization having 30 or more carbon atoms such as squalane Examples thereof include hydrogen.
これら分散媒は、室温で安定的に保存でき、さらに低温焼結時における蒸散を抑える点から、引火点が５０℃以上かつ沸点が１５０℃以上の有機溶媒が好ましく、例えば、ヘキシルジグリコール、テルピネオールを挙げることができる。 These dispersion media are preferably organic solvents having a flash point of 50 ° C. or higher and a boiling point of 150 ° C. or higher from the viewpoint of being able to be stably stored at room temperature and suppressing transpiration during low-temperature sintering, for example, hexyl diglycol, terpineol Can be mentioned.
分散媒の配合量は、所望の粘度に応じて適宜配合可能であるが、金属ナノ粒子と第２の金属粒子を含有した金属粉１００質量部に対して、例えば、１〜３００質量部であり、塗膜のひび割れを防止する点から２０〜２００質量部が好ましい。導電性材料をペースト状にする場合、Ｂ型粘度計における粘度は、例えば、２５℃において５Pa・s〜４００Pa・sであり、塗布の作業性の点から２５℃において２０Pa・s〜３００Pa・sが好ましく、スクリーン印刷またはディスペンサー等による塗布及び潤滑剤としての機能の点から、２５℃において５０Pa・s〜２００Pa・sが特に好ましい。また、これらの分散媒は単独で使用してもよく２種以上を混合して使用してもよい。 Although the compounding quantity of a dispersion medium can be mix | blended suitably according to desired viscosity, it is 1-300 mass parts with respect to 100 mass parts of metal powder containing the metal nanoparticle and the 2nd metal particle, for example. From the point which prevents the crack of a coating film, 20-200 mass parts is preferable. When the conductive material is made into a paste, the viscosity in the B-type viscometer is, for example, 5 Pa · s to 400 Pa · s at 25 ° C., and 20 Pa · s to 300 Pa · s at 25 ° C. from the viewpoint of coating workability. In view of application by screen printing or dispenser and function as a lubricant, 50 Pa · s to 200 Pa · s at 25 ° C. is particularly preferable. Moreover, these dispersion media may be used independently and may mix and use 2 or more types.
導電性材料には、用途に応じて、適宜、慣用の添加剤を配合してもよい。添加剤としては、例えば、光沢付与剤、金属腐食防止剤、安定剤、流動性向上剤、分散安定化剤、増粘剤、粘度調整剤、保湿剤、チクソトロピー性賦与剤、消泡剤、殺菌剤、充填材などを挙げることができる。これらの添加剤は、単独で使用してもよく、２種以上を混合して使用してもよい。 Conventional additives may be appropriately blended in the conductive material depending on the application. Examples of additives include gloss imparting agents, metal corrosion inhibitors, stabilizers, fluidity improvers, dispersion stabilizers, thickeners, viscosity modifiers, moisturizers, thixotropic agents, antifoaming agents, and bactericides. An agent, a filler, etc. can be mentioned. These additives may be used alone or in combination of two or more.
次に、本発明の導電性材料の製造方法について説明する。導電性材料の製造方法は特に限定されず、例えば、金属ナノ粒子と第２の金属粒子を汎用の混合器にて混合することにより製造できる。また、導電性材料を所定の粘度に調整したい、例えばペースト状にしたい場合には、所定量の分散媒に、金属ナノ粒子と第２の金属粒子とを添加し分散させることにより得られる。 Next, the manufacturing method of the electroconductive material of this invention is demonstrated. The method for producing the conductive material is not particularly limited. For example, the conductive material can be produced by mixing the metal nanoparticles and the second metal particles with a general-purpose mixer. Further, when it is desired to adjust the conductive material to a predetermined viscosity, for example, to form a paste, it is obtained by adding and dispersing metal nanoparticles and second metal particles in a predetermined amount of dispersion medium.
次に、本発明の導電性材料の用途例及び使用方法例について説明する。本発明の導電性材料は、種々の用途に使用可能である。本発明の導電性材料は、金属ナノ粒子を含み、また、この金属ナノ粒子は、その構成成分の金属種の融点よりも低い温度（例えば、銀、銅の場合２００℃程度）で焼結可能である、すなわち低温焼結性を有する。従って、本発明の導電性材料は金属ナノ粒子を含むことから低温焼結性を有するので、部品間を金属接合する材料、例えば、プリント配線板等の基板に電子部品を電気的かつ物理的に接合する導電性の接合材料や、導電性膜を形成する膜材料、例えば、プリント配線板等の基板に配線パターンを形成する配線材料としての用途がある。 Next, application examples and usage examples of the conductive material of the present invention will be described. The conductive material of the present invention can be used for various applications. The conductive material of the present invention includes metal nanoparticles, and the metal nanoparticles can be sintered at a temperature lower than the melting point of the constituent metal species (for example, about 200 ° C. in the case of silver and copper). That is, it has low temperature sinterability. Therefore, since the conductive material of the present invention contains metal nanoparticles, it has low-temperature sinterability. Therefore, an electronic component is electrically and physically connected to a material for metal bonding between components, for example, a substrate such as a printed wiring board. There is an application as a conductive bonding material to be bonded, a film material for forming a conductive film, for example, a wiring material for forming a wiring pattern on a substrate such as a printed wiring board.
導電性の接合材料として使用する場合、例えば、基板上の電子部品を接合する位置に、本発明の導電性材料を塗布し、塗布した導電性材料膜の上に電子部品を載置後、焼成処理して、基板上に電子部品を接合する。導電性材料の塗布方法は、特に限定されず、例えば、スクリーン印刷法、ディスペンサー法、インクジェット法などが挙げられる。導電性材料の塗布量は、適宜選択可能であり、例えば、１〜２０μｍの厚さにて塗布する。焼成温度は、金属ナノ粒子が相互に融着して低温焼結する温度であれば、特に限定されず、例えば、金属ナノ粒子が銅または銀の場合、１８０〜２３０℃であり、好ましくは１９０〜２１０℃である。また、焼成時間は、適宜選択可能であり、例えば、５〜１２０分である。使用する基板の材質は、特に限定されず、ガラス類、金属酸化物等の無機材料に加えて、本発明の導電性材料は低温焼結性を有するので、無機材料に比べて耐熱性の劣るポリエステル系樹脂、ポリカーボネート系樹脂、スチレン系樹脂、フッ素樹脂などの有機材料も使用できる。 When used as a conductive bonding material, for example, the conductive material of the present invention is applied to the position where the electronic component is bonded on the substrate, and the electronic component is placed on the applied conductive material film and then fired. Processing to bond electronic components on the substrate. The method for applying the conductive material is not particularly limited, and examples thereof include a screen printing method, a dispenser method, and an ink jet method. The application amount of the conductive material can be selected as appropriate. For example, the conductive material is applied in a thickness of 1 to 20 μm. The firing temperature is not particularly limited as long as the metal nanoparticles are fused to each other and sintered at a low temperature. For example, when the metal nanoparticles are copper or silver, the firing temperature is 180 to 230 ° C., preferably 190. ~ 210 ° C. Moreover, baking time can be selected suitably, for example, is 5 to 120 minutes. The material of the substrate to be used is not particularly limited, and in addition to inorganic materials such as glass and metal oxides, the conductive material of the present invention has low-temperature sinterability, so it has poor heat resistance compared to inorganic materials. Organic materials such as polyester resins, polycarbonate resins, styrene resins, and fluororesins can also be used.
また、導電性の配線材料として使用する場合、例えば、基板上に、導電性材料にて所望の配線パターンを描画し、描画された配線パターンを焼成処理して、基板上に焼結した配線パターンを形成する。導電性材料の塗布方法は、配線パターンの形成可能な塗布方法であれば特に限定されず、例えば、スクリーン印刷法、インクジェット法などが挙げられる。なお、導電性材料の塗布量、焼成条件、使用可能な基板の材質は、上記した導電性の接合材料として使用する場合と同様に適宜選択可能である。この使用方法例は、金属粉に金属ナノ粒子が配合されていることを利用して、微細な配線パターンの形成にも適用することができる。 When used as a conductive wiring material, for example, a wiring pattern in which a desired wiring pattern is drawn with a conductive material on a substrate, the drawn wiring pattern is baked, and then sintered on the substrate. Form. The coating method of the conductive material is not particularly limited as long as it is a coating method capable of forming a wiring pattern, and examples thereof include a screen printing method and an ink jet method. The application amount of the conductive material, the firing conditions, and the usable substrate material can be appropriately selected as in the case of using the conductive bonding material. This usage example can be applied to the formation of fine wiring patterns by utilizing the fact that metal nanoparticles are blended in metal powder.
次に、実施例を用いて本発明をさらに詳細に説明する。ただし、本発明は、以下に示す実施例の態様に限定されるものではない。 Next, the present invention will be described in more detail using examples. However, this invention is not limited to the aspect of the Example shown below.
実施例１〜１１、比較例１〜３
以下に、本発明の導電性材料を導電性の接合材料、導電性の配線材料として使用した実施例を説明する。
Examples 1-11, Comparative Examples 1-3
Hereinafter, examples in which the conductive material of the present invention is used as a conductive bonding material and a conductive wiring material will be described.
（１）導電性材料の配合成分について
（A）金属ナノ粒子
・市販の銀ナノ粒子「ＴＩＶ‐Ａ０１」（ＤＯＷＡエレクトロニクス（株）製）を用いた。このナノ粒子は平均一次粒子径が２０nmの粉末であり、５質量％のヘキサン酸で被覆されている。
（B）第２の金属粒子
・銀粒子１：球状、平均一次粒子径３．５μｍ、被覆なし
・銀粒子２：球状、平均一次粒子径３．５μｍ、イミダゾール誘導体被覆品
・銅粒子１：球状、平均一次粒子径３．０μｍ、被覆なし
・銅粒子２：球状、平均一次粒子径３．０μｍ、イミダゾール誘導体被覆品
・銅粒子３：球状、平均一次粒子径３．０μｍ、銀コート品
(1) About the compounding component of electroconductive material (A) Metal nanoparticle and commercially available silver nanoparticle "TIV-A01" (made by DOWA Electronics Co., Ltd.) were used. These nanoparticles are powders having an average primary particle size of 20 nm and are coated with 5% by mass of hexanoic acid.
(B) Second metal particle / silver particle 1: spherical, average primary particle size 3.5 μm, no coating / silver particle 2: spherical, average primary particle size 3.5 μm, imidazole derivative coated product / copper particle 1: spherical , Average primary particle size 3.0 μm, uncoated copper particles 2: spherical, average primary particle size 3.0 μm, imidazole derivative coated product, copper particles 3: spherical, average primary particle size 3.0 μm, silver coated product
上記イミダゾール誘導体として、２−フェニル−４−（２−メトキシ）フェニルイミダゾールを使用した。また、熱重量分析法（TG‐DTA法）により測定した結果、銀粒子２と銅粒子２は、いずれも、３質量％のイミダゾール誘導体被覆量であった。銅粒子３である銀コート品は、福田金属箔粉工業（株）製の「AgコートCu‐HWQ５μｍ」、銀被覆量は１０質量％である。 As the imidazole derivative, 2-phenyl-4- (2-methoxy) phenylimidazole was used. Moreover, as a result of measuring by the thermogravimetric analysis method (TG-DTA method), as for the silver particle 2 and the copper particle 2, all were 3 mass% imidazole derivative coating amount. The silver coat product which is the copper particle 3 is “Ag coat Cu-HWQ 5 μm” manufactured by Fukuda Metal Foil Powder Co., Ltd., and the silver coating amount is 10 mass%.
上記イミダゾール誘導体で被覆した第２の金属粒子（銀粒子２、銅粒子２）の製造は、以下の通りに実施した。まず、２−フェニル−４−（２−メトキシ）フェニルイミダゾール０．３gを、酢酸１０ｇに溶解させた後、臭化亜鉛０．０５gを溶解させ、全量を純水で１００ｇにした。次いで、１７％アンモニア水にてｐＨ４に調整し、被覆形成可能な処理液を調製した。次いで、前記処理液に、第２の金属粒子１０ｇを４０℃で２時間、浸漬、攪拌した後、処理液から第２の金属粒子を取り出して、水洗、乾燥することで、イミダゾール誘導体で被覆された第２の金属粒子を製造した。 The production of the second metal particles (silver particles 2, copper particles 2) coated with the imidazole derivative was carried out as follows. First, 0.3 g of 2-phenyl-4- (2-methoxy) phenylimidazole was dissolved in 10 g of acetic acid, 0.05 g of zinc bromide was dissolved, and the total amount was adjusted to 100 g with pure water. Next, the pH was adjusted to 4 with 17% aqueous ammonia to prepare a treatment solution capable of forming a coating. Next, after 10 g of the second metal particles were immersed in the treatment liquid at 40 ° C. for 2 hours and stirred, the second metal particles were taken out from the treatment liquid, washed with water, and dried to be coated with the imidazole derivative. Second metal particles were produced.
（２）導電性の接合材料、導電性の配線材料として使用する導電性材料の調製方法
金属ナノ粒子と、銀粒子１、２、銅粒子１〜３のいずれかと、粘度調整用の分散媒とを加え、乳棒を用いて５分間混合することで導電性材料のペーストを調製した。
(2) Method for preparing conductive material used as conductive bonding material and conductive wiring material Metal nanoparticles, any one of silver particles 1 and 2, and copper particles 1 to 3, and a dispersion medium for viscosity adjustment Was added and mixed for 5 minutes using a pestle to prepare a paste of conductive material.
前記導電性材料の調製方法を用いて、下記表１に示す金属ナノ粒子と第２の金属粒子の各成分を下記表１に示す配合割合にて配合することで、実施例１〜１１及び比較例１〜３の導電性材料のペーストを調製した。実施例１〜１１、比較例１〜３ともに、分散媒の配合量は、金属ナノ粒子と第２の金属粒子からなる金属粉１００質量部に対して２０質量部とした。また、分散媒には、ターピネオールＣ（日本テルペン（株）製、α‐、β‐、γ‐テルピネオール混合物）を使用した。なお、下記表１に示す金属ナノ粒子と第２の金属粒子の配合量は質量％を表す。 By using the method for preparing the conductive material, the components of the metal nanoparticles and the second metal particles shown in Table 1 below are blended at the blending ratios shown in Table 1 below. Conductive material pastes of Examples 1-3 were prepared. In each of Examples 1 to 11 and Comparative Examples 1 to 3, the amount of the dispersion medium was 20 parts by mass with respect to 100 parts by mass of metal powder composed of metal nanoparticles and second metal particles. As the dispersion medium, terpineol C (manufactured by Nippon Terpene Co., Ltd., α-, β-, γ-terpineol mixture) was used. In addition, the compounding quantity of the metal nanoparticle shown in following Table 1 and a 2nd metal particle represents the mass%.
（３）性能評価
（一）チップ部品のせん断強度
表面にNi／Auめっきが施された銅基板上に、上記のように調製した導電性材料のペーストを１５０μｍｔのメタルマスクを用いてメタルスキージで印刷し、２ｍｍ×２ｍｍのNi／Auめっき銅チップを銅基板の印刷膜上に１０個載置した。そして、２００℃、６０分間のオーブン加熱にて、銅基板上に載置したNi／Auめっき銅チップを接合して試験片を作製した。この試験片について、引張り試験機（SHIMADZU（株）製EZ-L)を用いて、５ｍｍ／minの条件でNi／Auめっき銅チップのせん断強度を測定した。なお、測定結果は、せん断強度を測定した１０個のNi／Auめっき銅チップの平均値である。
(3) Performance evaluation (1) Shear strength of chip parts On a copper substrate with Ni / Au plating on the surface, paste the conductive material prepared as described above with a metal squeegee using a 150 μmt metal mask. After printing, 10 Ni / Au plated copper chips of 2 mm × 2 mm were placed on the printed film of the copper substrate. And the Ni / Au plating copper chip mounted on the copper substrate was joined by 200 degreeC and 60 minute oven heating, and the test piece was produced. About this test piece, the shear strength of the Ni / Au plating copper chip was measured on condition of 5 mm / min using the tensile testing machine (EZ-L by SHIMADZU Co., Ltd.). In addition, a measurement result is an average value of ten Ni / Au plating copper chips which measured shear strength.
（二）体積抵抗
スライドガラス上に、上記のように調製した導電性材料のペーストをスクリーン印刷で長さ５ｃｍ×幅１ｃｍで塗布し、２００℃、６０分間のオーブン加熱にて、塗膜を焼成後、膜厚を測定し、岩通計測（株）製マイクロメーターを用いて抵抗値を測定することにより、体積抵抗（比抵抗）値を算出した。
(2) Volume resistance The conductive material paste prepared as described above was applied on a slide glass by screen printing in a length of 5 cm x width of 1 cm, and the coating film was baked by heating at 200 ° C for 60 minutes. Thereafter, the film thickness was measured, and the volume resistance (specific resistance) value was calculated by measuring the resistance value using a micrometer manufactured by Iwadori Measurement Co., Ltd.
実施例１〜１１、比較例１〜３の評価結果を下記表２に示す。 The evaluation results of Examples 1 to 11 and Comparative Examples 1 to 3 are shown in Table 2 below.
表２のチップ部品のせん断強度について、「測定不可」とは、Ni／Auめっき銅チップを銅基板上に接合できなかったために、チップ部品のせん断強度を測定できなかったことを意味する。 Regarding the shear strength of the chip parts in Table 2, “impossible to measure” means that the shear strength of the chip parts could not be measured because the Ni / Au plated copper chip could not be bonded onto the copper substrate.
表２に示すように、導電性材料として、金属ナノ粒子と第２の金属粒子と配合した金属粉を用いると、金属ナノ粒子または第２の金属粒子を配合したものと比較して、チップ部品のせん断強度が向上して、機械的強度に優れた金属接合が得られた。実施例１と実施例８、実施例９と実施例１０との対比から、第２の金属粒子をイミダゾール誘導体で被覆することにより、さらにチップ部品のせん断強度が向上した。実施例９と実施例１１から、銅粒子の表面を銀でコートすることにより、チップ部品のせん断強度がさらに向上して、銀粒子を配合した場合と同程度近くまで金属接合部の機械的強度が得られた。また、金属ナノ粒子の配合量を１〜３０質量％とすることで、チップ部品のせん断強度がより一層向上した。 As shown in Table 2, when a metal powder blended with metal nanoparticles and second metal particles is used as the conductive material, the chip component is compared with a blend of metal nanoparticles or second metal particles. As a result, the shear strength of the metal was improved, and a metal joint excellent in mechanical strength was obtained. From the comparison between Example 1 and Example 8, Example 9 and Example 10, the shear strength of the chip component was further improved by coating the second metal particles with an imidazole derivative. From Example 9 and Example 11, by coating the surface of the copper particles with silver, the shear strength of the chip part is further improved, and the mechanical strength of the metal joint is nearly the same as when silver particles are blended. was gotten. Moreover, the shear strength of the chip part was further improved by setting the blending amount of the metal nanoparticles to 1 to 30% by mass.
表２に示すように、導電性材料として、金属ナノ粒子と第２の金属粒子と配合した金属粉を用いると、金属ナノ粒子または第２の金属粒子を配合したものと比較して、体積抵抗が低減して、導通性に優れた配線パターンが形成できた。実施例１と実施例８、実施例９と実施例１０との対比から、第２の金属粒子をイミダゾール誘導体で被覆しても体積抵抗は損なわれなかった。実施例９と実施例１１から、銅粒子の表面を銀でコートすることにより、体積抵抗がさらに低減して、銀粒子を配合した場合と同程度近くまで配線パターンの導通性が得られた。また、金属ナノ粒子の配合量を１〜３０質量％とすることで、配線パターンの導通性がより一層向上した。 As shown in Table 2, when a metal powder blended with metal nanoparticles and second metal particles is used as the conductive material, it has a volume resistance as compared with that blended with metal nanoparticles or second metal particles. As a result, a wiring pattern having excellent conductivity could be formed. From comparison between Example 1 and Example 8 and Example 9 and Example 10, the volume resistance was not impaired even when the second metal particles were coated with an imidazole derivative. From Example 9 and Example 11, by coating the surface of the copper particles with silver, the volume resistance was further reduced, and the conductivity of the wiring pattern was obtained to the same extent as when silver particles were blended. Moreover, the electroconductivity of the wiring pattern was further improved by making the compounding quantity of a metal nanoparticle into 1-30 mass%.
本発明の導電性材料は、金属ナノ粒子及び第２の金属粒子の融点よりも低温の熱処理で基板と電子部品を電気的に接合でき、また前記低温の熱処理で基板上に配線パターンを形成できるので、特に、プリント配線板上に電子部品を実装する分野で利用価値が高い。 The conductive material of the present invention can electrically bond the substrate and the electronic component by a heat treatment at a temperature lower than the melting point of the metal nanoparticles and the second metal particles, and can form a wiring pattern on the substrate by the low-temperature heat treatment. Therefore, the utility value is particularly high in the field of mounting electronic components on a printed wiring board.
Claims (6)
前記（Ｂ）第２の金属粒子が、下記一般式
前記（Ｃ）分散媒が、α‐テルピネオールとβ‐テルピネオールとγ‐テルピネオールとの混合物であることを特徴とする導電性材料。 (A) metal nanoparticles having an average primary particle diameter of 7 to 50 nm and (B) at least one second metal particle selected from the group consisting of silver and copper having an average primary particle diameter of 3 to 20 μm And (C) a dispersion medium containing a conductive powder,
The (B) second metal particles have the following general formula:
Wherein (C) the dispersion medium, a conductive material characterized mixture der Rukoto of α- terpineol and β- terpineol and γ- terpineol.
前記塗工した回路形成用基板を、１８０〜２３０℃で加熱して、前記電極及び配線パターンを焼成処理する工程と、を備えることを特徴とする回路形成方法。 Applying a conductive material according to any one of claims 1 to 3 on a circuit forming substrate to form an electrode and a wiring pattern;
Heating the coated circuit-forming substrate at 180 to 230 ° C. and firing the electrodes and the wiring pattern.
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| JP6153076B2 (en) * | 2013-05-22 | 2017-06-28 | 株式会社豊田中央研究所 | Metal nanoparticle paste, bonding material containing the same, and semiconductor device using the same |
| CN103366858B (en) * | 2013-07-08 | 2015-10-14 | 广东羚光新材料股份有限公司 | A kind of LED aluminium oxide pedestal silver slurry and application thereof |
| CN105473257B (en) * | 2013-09-05 | 2018-11-13 | 汉高知识产权控股有限责任公司 | Metal sintering film composition |
| JP5642312B1 (en) * | 2014-05-13 | 2014-12-17 | イサハヤ電子株式会社 | Semiconductor device and manufacturing method thereof |
| US9505058B2 (en) * | 2014-05-16 | 2016-11-29 | Xerox Corporation | Stabilized metallic nanoparticles for 3D printing |
| KR20150142090A (en) * | 2014-06-10 | 2015-12-22 | 전자부품연구원 | Adhesives for die bonding and die bonding structure using the same |
| WO2016121764A1 (en) * | 2015-01-26 | 2016-08-04 | 新日鐵住金株式会社 | Conductive joining material and conductive joining structure which use metal particles and conductive material particles |
| JP6524780B2 (en) | 2015-04-20 | 2019-06-05 | セイコーエプソン株式会社 | METHOD FOR MANUFACTURING ELECTRICAL WIRING MEMBER, MATERIAL FOR FORMING ELECTRICAL WIRING MEMBER, ELECTRICAL WIRING MEMBER, METHOD FOR MANUFACTURING ELECTRICAL WIRING BOARD, MATERIAL FOR FORMING ELECTRICAL WIRING BOARD, ELECTRIC WIRING BOARD, OSCILLATOR, ELECTRONIC EQUIPMENT AND MOVING BODY |
| EP3294799A4 (en) | 2015-05-08 | 2018-11-21 | Henkel IP & Holding GmbH | Sinterable films and pastes and methods for the use thereof |
| JP6130616B1 (en) | 2017-02-07 | 2017-05-17 | 大陽日酸株式会社 | Copper fine particles, production method thereof, and sintered body |
| WO2019026799A1 (en) * | 2017-07-31 | 2019-02-07 | バンドー化学株式会社 | Composition for metal bonding, metal bonded laminate and electric control device |
| WO2019092959A1 (en) * | 2017-11-13 | 2019-05-16 | 日東電工株式会社 | Composition for sinter bonding, sheet for sinter bonding, and dicing tape with sheet for sinter bonding |
| JP6583391B2 (en) | 2017-11-14 | 2019-10-02 | 千住金属工業株式会社 | Flux, flux cored solder and flux coated pellets |
| JP2020047378A (en) * | 2018-09-14 | 2020-03-26 | バンドー化学株式会社 | Conductive fine particle dispersion |
| JP2020184530A (en) | 2019-05-01 | 2020-11-12 | デクセリアルズ株式会社 | Connection structure, manufacturing method thereof, connection material, and coated conductive particles |
Family Cites Families (12)
| Publication number | Priority date | Publication date | Assignee | Title |
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| JPH0465011A (en) * | 1990-07-04 | 1992-03-02 | Sumitomo Metal Ind Ltd | Copper conductive paste |
| JPH08218006A (en) * | 1995-02-17 | 1996-08-27 | Hitachi Chem Co Ltd | Electroconductive paste |
| JP4493658B2 (en) * | 2005-05-25 | 2010-06-30 | 千住金属工業株式会社 | Lead-free solder paste |
| JP4852272B2 (en) * | 2005-07-25 | 2012-01-11 | ナミックス株式会社 | Metal paste |
| JP4963393B2 (en) * | 2006-10-03 | 2012-06-27 | 三ツ星ベルト株式会社 | Low temperature firing type silver paste |
| US20100009153A1 (en) * | 2008-06-12 | 2010-01-14 | Nanomas Technologies, Inc. | Conductive inks and pastes |
| JP2010044967A (en) * | 2008-08-13 | 2010-02-25 | Sumitomo Electric Ind Ltd | Conductive adhesive and led substrate using it |
| JP5361316B2 (en) * | 2008-10-02 | 2013-12-04 | 株式会社タムラ製作所 | Surface treatment agent, printed circuit board, and manufacturing method thereof |
| JP5363793B2 (en) * | 2008-11-28 | 2013-12-11 | 積水化学工業株式会社 | Conductive particle, anisotropic conductive material, connection structure, and method for producing conductive particle |
| KR101225497B1 (en) * | 2009-11-05 | 2013-01-23 | (주)덕산테코피아 | Conductive paste and the manufacturing method thereof and the electric device comprising thereof |
| CN103250236B (en) * | 2010-11-22 | 2016-09-14 | 同和电子科技有限公司 | Grafting material and conjugant and joint method |
| US9221130B2 (en) * | 2010-12-17 | 2015-12-29 | Furukawa Electric Co., Ltd. | Material for thermal bonding, coating material for thermal bonding, coating, and electronic component bonding method |
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