JP2002275509A - Method for manufacturing metal powder, metal powder, conductive paste which uses the same and multilayer ceramic electronic parts which use the same - Google Patents

Method for manufacturing metal powder, metal powder, conductive paste which uses the same and multilayer ceramic electronic parts which use the same

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Publication number
JP2002275509A
JP2002275509A JP2001074807A JP2001074807A JP2002275509A JP 2002275509 A JP2002275509 A JP 2002275509A JP 2001074807 A JP2001074807 A JP 2001074807A JP 2001074807 A JP2001074807 A JP 2001074807A JP 2002275509 A JP2002275509 A JP 2002275509A
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JP
Japan
Prior art keywords
metal powder
metal
reducing agent
solvent
mωcm
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.)
Pending
Application number
JP2001074807A
Other languages
Japanese (ja)
Inventor
Tadashi Hosokura
匡 細倉
Masayoshi Maeda
昌禎 前田
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Murata Manufacturing Co Ltd
Original Assignee
Murata Manufacturing Co Ltd
Priority date (The priority date 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 date listed.)
Filing date
Publication date
Application filed by Murata Manufacturing Co Ltd filed Critical Murata Manufacturing Co Ltd
Priority to JP2001074807A priority Critical patent/JP2002275509A/en
Publication of JP2002275509A publication Critical patent/JP2002275509A/en
Pending legal-status Critical Current

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  • Manufacture Of Metal Powder And Suspensions Thereof (AREA)
  • Ceramic Capacitors (AREA)
  • Fixed Capacitors And Capacitor Manufacturing Machines (AREA)
  • Conductive Materials (AREA)

Abstract

PROBLEM TO BE SOLVED: To provide a method for manufacturing metal powder of fine particles having no coarse particles and little variance in the particle size and to provide the metal powder, a conductive paste which uses the powder, and multilayer ceramic electronic parts which use the powder. SOLUTION: The method for manufacturing metal powder is carried out by incorporating metal salts and a reducing agent into a solvent containing water and having 1>=MΩcm resistivity and reducing the metal salts by the effect of the reducing agent in the mixture liquid in which at least a part of the metal salts or the reducing agent is dissolved in the solvent so as to precipitate the metal powder of the metals included in the metal salts.

Description

【発明の詳細な説明】DETAILED DESCRIPTION OF THE INVENTION

【0001】[0001]

【発明の属する技術分野】本発明は、金属粉末の製造方
法,金属粉末,これを用いた導電性ペーストならびにこ
れを用いて内部電極を形成した積層セラミック電子部品
に関するものである。
BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for producing metal powder, a metal powder, a conductive paste using the same, and a multilayer ceramic electronic component using the same to form internal electrodes.

【0002】[0002]

【従来の技術】従来、積層セラミック電子部品、例えば
積層セラミックコンデンサは、誘電体材料からなるセラ
ミック層が積層状態にあるセラミック積層体と、セラミ
ック層間にあって積層状態にある内部電極と、セラミッ
ク積層体の両端部に形成された端子電極とからなる。
2. Description of the Related Art Conventionally, a multilayer ceramic electronic component, for example, a multilayer ceramic capacitor, includes a ceramic laminate in which ceramic layers made of a dielectric material are laminated, an internal electrode in a laminated state between ceramic layers, and a ceramic laminate. And terminal electrodes formed at both ends of the terminal.

【0003】このような積層セラミック電子部品、特に
積層セラミックコンデンサの内部電極形成には導電性ペ
ーストが用いられる。導電性ペーストは、導電成分とし
て機能する金属粉末を含有し、金属粉末としては銀やパ
ラジウム等の貴金属に加えて、近年ではニッケルや銅粉
末等の卑金属が用いられるようになっている。また、積
層セラミック電子部品はその小型化ならびに薄層化が進
み、これに伴い内部電極形成に用いる導電性ペーストに
含有する金属粉末の微粒化が求められる。
A conductive paste is used for forming internal electrodes of such a multilayer ceramic electronic component, particularly a multilayer ceramic capacitor. The conductive paste contains a metal powder that functions as a conductive component. As the metal powder, in addition to a noble metal such as silver or palladium, a base metal such as nickel or copper powder has recently been used. In addition, the multilayer ceramic electronic component has been reduced in size and thickness, and accordingly, it has been required to reduce the metal powder contained in the conductive paste used for forming the internal electrodes.

【0004】[0004]

【発明が解決しようとする課題】しかしながら、従来技
術によれば、水中に電気伝導性の不純物が存在する場
合、水の伝導度は大きくなる。このような不純物の存在
する水を溶媒として用いると、不純物が核となることで
析出する金属粉末の粒成長が容易になり、粒径がばらつ
いて金属粉末中に粗大粒子が存在する場合があった。こ
のような金属粉末を含有してなる導電性ペーストを用い
て内部電極を形成すると、導電性ペーストを印刷した塗
膜上で粗大粒子が凸部となり、これが上下に積層される
セラミック層を突き破り、セラミック層を介して上下に
積層される内部電極層同士が短絡して、ショート不良が
発生するという問題点を有していた。
However, according to the prior art, when electric conductive impurities are present in water, the conductivity of the water increases. When water containing such impurities is used as a solvent, the impurities serve as nuclei, which facilitates the growth of the particles of the metal powder that precipitates, and the particle diameter varies, and coarse particles may be present in the metal powder. Was. When an internal electrode is formed using a conductive paste containing such a metal powder, coarse particles become convex portions on the coating film on which the conductive paste is printed, and this breaks through the ceramic layers stacked vertically, There has been a problem that the internal electrode layers stacked one above the other via the ceramic layer are short-circuited, and short-circuit failure occurs.

【0005】本発明の目的は、上述の問題点を解消すべ
くなされたもので、粗大粒子の存在しない、粒径のバラ
ツキの少ない微粒の金属粉末の製造方法,金属粉末,こ
れを用いた導電性ペーストならびにこれを用いた積層セ
ラミック電子部品を提供することにある。
SUMMARY OF THE INVENTION An object of the present invention is to solve the above-mentioned problems, and it is an object of the present invention to provide a method for producing a fine metal powder having no coarse particles and a small variation in particle diameter, a metal powder, and a conductive powder using the same. An object of the present invention is to provide a conductive paste and a multilayer ceramic electronic component using the same.

【0006】[0006]

【課題を解決するための手段】上記目的を達成するため
に、本発明の金属粉末の製造方法は、抵抗率が1MΩc
m以上である水を含む溶媒に、金属塩と、還元剤と、を
含有させ、金属塩または還元剤の少なくとも一部が溶媒
中に溶解した混合液中で、還元剤の働きで金属塩を還元
させ、金属塩に含まれる金属からなる金属粉末を析出さ
せること、を特徴とする。
In order to achieve the above object, a method for producing a metal powder according to the present invention has a resistivity of 1 MΩc.
m, a metal salt and a reducing agent are contained in a solvent containing water, and in a mixed solution in which at least a part of the metal salt or the reducing agent is dissolved in the solvent, the metal salt is formed by the action of the reducing agent. Reducing, and depositing a metal powder composed of a metal contained in the metal salt.

【0007】また、還元剤溶液は、ヒドラジン,ヒドラ
ジン水和物,水素化ホウ素化合物,アミノボラザン系還
元剤よりなる群から選ばれる少なくとも1種であること
が好ましい。
The reducing agent solution is preferably at least one selected from the group consisting of hydrazine, hydrazine hydrate, a borohydride compound, and an aminoborazane-based reducing agent.

【0008】また、金属塩に含まれる金属は、Pd,C
u,Ni,Agよりなる群から選ばれる少なくとも1種
であることが好ましい。
The metal contained in the metal salt is Pd, C
It is preferably at least one selected from the group consisting of u, Ni, and Ag.

【0009】また、金属塩は、塩化物,硫酸塩および硝
酸塩よりなる群から選ばれる少なくとも1種であること
が好ましい。
The metal salt is preferably at least one selected from the group consisting of chloride, sulfate and nitrate.

【0010】また、溶媒は、抵抗率が1MΩcm以上で
ある水単体、または抵抗率が1MΩcm以上である水と
アルコールとの混合溶媒であることが好ましい。
The solvent is preferably a simple substance of water having a resistivity of 1 MΩcm or more, or a mixed solvent of water and an alcohol having a resistivity of 1 MΩcm or more.

【0011】本発明の金属粉末は、上述した本発明の金
属粉末の製造方法によって得られたことを特徴とする。
[0011] The metal powder of the present invention is characterized by being obtained by the above-described method for producing a metal powder of the present invention.

【0012】本発明の導電性ペーストは、上述した本発
明の金属粉末と、有機ビヒクルと、を含有してなること
を特徴とする。
The conductive paste of the present invention is characterized by containing the above-mentioned metal powder of the present invention and an organic vehicle.

【0013】本発明の積層セラミック電子部品は、複数
のセラミック層が積層状態にあるセラミック積層体と、
セラミック層間に形成された複数の内部電極と、を備
え、内部電極は、請求項7に記載の導電性ペーストを用
いて形成されていることを特徴とする。
A multilayer ceramic electronic component according to the present invention comprises: a ceramic laminate in which a plurality of ceramic layers are stacked;
And a plurality of internal electrodes formed between the ceramic layers, wherein the internal electrodes are formed using the conductive paste according to claim 7.

【0014】[0014]

【発明の実施の形態】本発明の金属粉末の製造方法は、
まず抵抗率が1MΩcm以上である水を含む溶媒を用い
る点に特徴がある。抵抗率が1MΩcm以上である水を
含む溶媒であれば、水の伝導度を大きくする要因となる
電気伝導性の不純物が極めて少ないため、金属イオンを
金属粉末として析出させる際に不純物が核となりにく
い。したがって、粗大粒子が少なく粒径の略揃った金属
粉末を製造することができる。
BEST MODE FOR CARRYING OUT THE INVENTION
First, it is characterized in that a solvent containing water having a resistivity of 1 MΩcm or more is used. In the case of a solvent containing water having a resistivity of 1 MΩcm or more, since there are very few electrically conductive impurities which cause an increase in water conductivity, the impurities are unlikely to become nuclei when metal ions are precipitated as metal powder. . Therefore, it is possible to produce a metal powder having a small amount of coarse particles and a substantially uniform particle size.

【0015】なお、金属塩は、還元剤によって金属を析
出し得るものであれば特に限定されるものではないが、
積層セラミック電子部品の内部電極形成の用に供される
導電性ペーストの導電成分として用いる場合、Pd,C
u,Ni,Agよりなる群から選ればれる少なくとも1
種であることが好ましい。また、金属塩は、選択される
溶媒に良好に溶解し得るものが好ましく、例えば塩化
物,硫酸塩および硝酸塩よりなる群から選ればれる少な
くとも1種であることが好ましい。
The metal salt is not particularly limited as long as it can precipitate a metal with a reducing agent.
When used as a conductive component of a conductive paste used for forming internal electrodes of a multilayer ceramic electronic component, Pd, C
at least one selected from the group consisting of u, Ni, and Ag
Preferably it is a seed. Further, the metal salt is preferably one that can be well dissolved in the selected solvent, and is preferably at least one selected from the group consisting of chlorides, sulfates and nitrates.

【0016】また、還元剤は、金属塩を還元し得るもの
であれば特に限定されるものではないが、例えばヒドラ
ジン,ヒドラジン水和物,水素化ホウ素化合物,アミノ
ボラザン系還元剤が挙げられる。特に、金属塩を還元し
て上述した金属粉末を得るためには、ヒドラジン水和物
または/および水素化ホウ素化合物を含有することがよ
り好ましい。
The reducing agent is not particularly limited as long as it can reduce the metal salt, and examples thereof include hydrazine, hydrazine hydrate, borohydride compounds, and aminoborazane-based reducing agents. In particular, in order to reduce the metal salt to obtain the above-mentioned metal powder, it is more preferable to contain hydrazine hydrate and / or a borohydride compound.

【0017】また、溶媒は、抵抗率が1MΩcm以上で
ある水単体でもよく、さらにアルコールを混合した混合
溶媒であっても構わない。また、溶媒に含有する抵抗率
が1MΩcm以上である水は、抵抗率が15MΩcm程
度であることがより好ましい。
The solvent may be water alone having a resistivity of 1 MΩcm or more, or may be a mixed solvent obtained by further mixing alcohol. Further, the water contained in the solvent having a resistivity of 1 MΩcm or more preferably has a resistivity of about 15 MΩcm.

【0018】本発明の金属粉末の製造方法の一つの実施
形態について、以下に説明する。まず、抵抗率が1MΩ
cm以上である水を含む溶媒を攪拌しながら、金属塩を
投入し、続いて還元剤を投入し、混合溶液を得る。な
お、還元剤の含有量は、特に限定はしないが、金属塩を
還元するために化学量論的に必要な量以上であることが
好ましい。必要量の10倍を上回る量の還元剤を含有さ
せても、余剰の還元剤は金属塩の還元に寄与しないこと
から、還元剤の含有量は、必要量の10倍以内であるこ
とが好ましい。
One embodiment of the method for producing a metal powder according to the present invention will be described below. First, the resistivity is 1MΩ
While stirring a solvent containing water having a diameter of not less than 1 cm, a metal salt is added thereto, and then a reducing agent is added thereto to obtain a mixed solution. The content of the reducing agent is not particularly limited, but is preferably not less than the amount stoichiometrically necessary for reducing the metal salt. Even if the amount of the reducing agent exceeds 10 times the required amount, the excess reducing agent does not contribute to the reduction of the metal salt. Therefore, the content of the reducing agent is preferably within 10 times the required amount. .

【0019】次いで、この混合溶液を加熱し、還元剤の
働きで金属塩を還元させて、金属粉末の析出を行なう。
なお、加熱温度は特に限定はしないが、50℃以上であ
ることが好ましい。
Next, the mixed solution is heated to reduce the metal salt by the action of the reducing agent, thereby depositing the metal powder.
The heating temperature is not particularly limited, but is preferably 50 ° C. or higher.

【0020】本発明の金属粉末は、上述した本発明の金
属粉末の製造方法によって得られたことを要する。
The metal powder of the present invention needs to be obtained by the above-described method for producing a metal powder of the present invention.

【0021】本発明の導電性ペーストは、上述した本発
明の金属粉末と、有機ビヒクルとを含有することを要す
る。なお、有機ビヒクルやその他の添加剤を含有するこ
とを妨げない。また、有機ビヒクルとしては、特に限定
はしないが、例えばエチルセルロースとアルキド樹脂か
らなる有機バインダ25重量%と、エチルカルビトー
ル,1−オクタノールおよびケロシン系溶媒とからなる
有機溶媒75重量%とを混合したもの等が挙げられる。
The conductive paste of the present invention needs to contain the above-mentioned metal powder of the present invention and an organic vehicle. In addition, it does not prevent containing an organic vehicle and other additives. The organic vehicle is not particularly limited. For example, 25% by weight of an organic binder composed of ethyl cellulose and an alkyd resin and 75% by weight of an organic solvent composed of ethyl carbitol, 1-octanol and a kerosene-based solvent are mixed. And the like.

【0022】本発明の積層セラミック電子部品の一つの
実施形態について、図1に基づいて詳細に説明する。す
なわち、積層セラミック電子部品1は、セラミック積層
体2と、内部電極3,3と、端子電極4,4と、めっき
膜5,5とから構成される。
One embodiment of the multilayer ceramic electronic component of the present invention will be described in detail with reference to FIG. That is, the laminated ceramic electronic component 1 includes a ceramic laminate 2, the internal electrodes 3, and the terminal electrodes 4, and a plated film 5,5 Prefecture.

【0023】セラミック積層体2は、BaTiO3を主
成分とする誘電体材料からなるセラミック層2aが複数
積層された生のセラミック積層体が焼成されてなる。
The ceramic laminate 2 is formed by firing a green ceramic laminate in which a plurality of ceramic layers 2a made of a dielectric material containing BaTiO 3 as a main component are laminated.

【0024】内部電極3,3は、セラミック積層体2内
のセラミック層2a間にあって、複数の生のセラミック
層2a上に本発明の導電性ペーストが印刷され、生のセ
ラミック層とともに積層されてなる生のセラミック積層
体と同時焼成されてなり、内部電極3,3のそれぞれの
端縁は、セラミック積層体2の何れかの端面に露出する
ように形成されている。
The internal electrodes 3, 3 are located between the ceramic layers 2a in the ceramic laminate 2, and the conductive paste of the present invention is printed on a plurality of green ceramic layers 2a and laminated together with the raw ceramic layers. It is fired at the same time as the raw ceramic laminate, and the respective edges of the internal electrodes 3 are formed so as to be exposed at any end face of the ceramic laminate 2.

【0025】端子電極4,4は、セラミック積層体2の
端面に露出した内部電極3,3の一端と電気的かつ機械
的に接合されるように、導電性ペーストがセラミック積
層体2の端面に塗布され焼付けられてなる。
The conductive paste is applied to the end face of the ceramic laminate 2 so that the terminal electrodes 4 and 4 are electrically and mechanically joined to one ends of the internal electrodes 3 and 3 exposed on the end face of the ceramic laminate 2. It is applied and baked.

【0026】めっき膜5,5は、例えば、SnやNi等
の無電解めっきや、はんだめっき等からなり、端子電極
4,4上に少なくとも1層形成されてなる。
The plating films 5 and 5 are made of, for example, electroless plating such as Sn or Ni, or solder plating, and are formed on the terminal electrodes 4 and 4 in at least one layer.

【0027】なお、本発明の積層セラミック電子部品の
セラミック積層体2の材料は、上述の実施形態に限定さ
れることなく、例えばPbZrO3等,その他の誘電体
材料,絶縁体,磁性体,圧電体ならびに半導体材料から
なっても構わない。また、本発明の積層セラミック電子
部品の内部電極3の枚数は、上述の実施形態に限定され
ることなく、また何層形成されていても構わない。ま
た、めっき膜5,5は、必ずしも備えている必要はな
く、また何層形成されていても構わない。
The material of the ceramic laminate 2 of the multilayer ceramic electronic component of the present invention is not limited to the above-described embodiment, but may be PbZrO 3 or another dielectric material, insulator, magnetic material, piezoelectric material, or the like. It may be made of a body or a semiconductor material. Further, the number of the internal electrodes 3 of the multilayer ceramic electronic component of the present invention is not limited to the above-described embodiment, and any number of layers may be formed. Further, the plating films 5 and 5 are not necessarily required to be provided, and any number of layers may be formed.

【0028】[0028]

【実施例】(実施例1)実施例1では、金属粉末として
ニッケルを生成し、これを用いた導電性ペースト,試験
サンプルならびに積層セラミック電子部品の一形態とし
て積層セラミックコンデンサを作製する。
(Example 1) In Example 1, nickel is produced as a metal powder, and a multilayer ceramic capacitor is produced as one form of a conductive paste, a test sample and a multilayer ceramic electronic component using the same.

【0029】まず、表1に示すように、溶媒として抵抗
率がそれぞれ0.4MΩcm,0.9MΩcm,1.1
MΩcm,2.5MΩcm,5.0MΩcm,10.0
MΩcm,17.0MΩcmである水を準備し、金属塩
である塩化ニッケル7gを上記水溶媒100mlに溶解
して試料1〜7の金属塩溶液を作成し、水酸化ナトリウ
ム3gと還元剤である80%抱水ヒドラジン10gを上
記水溶媒100mlに溶解して試料1〜7の還元剤溶液
を作成した。
First, as shown in Table 1, the solvent has a resistivity of 0.4 MΩcm, 0.9 MΩcm, and 1.1 MΩcm, respectively.
MΩcm, 2.5MΩcm, 5.0MΩcm, 10.0
Water having MΩcm and 17.0 MΩcm was prepared, and 7 g of nickel chloride as a metal salt was dissolved in 100 ml of the above-mentioned water solvent to prepare a metal salt solution of Samples 1 to 7, 3 g of sodium hydroxide and 80 as a reducing agent. 10 g of hydrazine hydrate was dissolved in 100 ml of the above aqueous solvent to prepare reducing agent solutions of Samples 1 to 7.

【0030】次いで、試料1〜7の金属塩溶液と還元剤
溶液を60℃に保ち、還元剤溶液に金属塩溶液を投入し
てニッケルを還元・析出させた後、これを分離・回収
し、純水ならびにアセトンで洗浄し、オーブン中で乾燥
させて、試料1〜7の金属粉末(ニッケル)を得た。
Next, the metal salt solution and the reducing agent solution of Samples 1 to 7 were maintained at 60 ° C., and the metal salt solution was added to the reducing agent solution to reduce and precipitate nickel, which was then separated and recovered. After washing with pure water and acetone and drying in an oven, metal powders (nickel) of Samples 1 to 7 were obtained.

【0031】そこで、試料1〜7のニッケル粉末を走査
型電子顕微鏡で観察し、デジタイザによって粒径を30
点測定し、平均粒径と粒径の標準偏差を求め、これを表
1にまとめた。
Then, the nickel powder of Samples 1 to 7 was observed with a scanning electron microscope, and the particle size was reduced to 30 with a digitizer.
The points were measured, and the average particle diameter and the standard deviation of the particle diameter were determined.

【0032】[0032]

【表1】 [Table 1]

【0033】表1から明らかであるように、試料1〜7
の平均粒径は何れも152〜158nmの範囲内で優れ
たが、溶媒である水の抵抗値が1MΩcm未満である試
料1,2の標準偏差は62〜65nmで大きいのに対し
て、水の抵抗値が1MΩcm以上である試料3〜7の標
準偏差は14〜19nmで小さいことが分かる。
As is clear from Table 1, samples 1 to 7
The average particle size of each sample was excellent in the range of 152 to 158 nm, whereas the standard deviation of samples 1 and 2 in which the resistance value of water as a solvent was less than 1 MΩcm was large at 62 to 65 nm, It can be seen that the standard deviation of samples 3 to 7 having a resistance value of 1 MΩcm or more is small at 14 to 19 nm.

【0034】続いて、試料1〜7の金属粉末50重量%
と、エチルセルロース10重量部をテルピネオール90
重量部に溶解させた有機ビヒクル40重量%と、テルピ
ネオール40重量%と、を混合し3本ロールミルを用い
て混練を行ない、試料1〜7の導電性ペーストを得た。
Subsequently, 50% by weight of the metal powder of Samples 1 to 7
And 10 parts by weight of ethylcellulose in terpineol 90
An organic vehicle 40% by weight dissolved in parts by weight and terpineol 40% by weight were mixed and kneaded using a three-roll mill to obtain conductive pastes of Samples 1 to 7.

【0035】そこで、試料1〜7の導電性ペーストをガ
ラス板上に塗布厚みが1.0μmとなるように印刷して
電極膜を形成し、触針式膜厚計を用いて電極膜の十点表
面粗さ(Rz)を測定し、これを表2にまとめた。
Therefore, the conductive pastes of Samples 1 to 7 were printed on a glass plate so as to have a coating thickness of 1.0 μm to form an electrode film, and the thickness of the electrode film was measured using a stylus-type film thickness meter. The point surface roughness (Rz) was measured and is summarized in Table 2.

【0036】続いて、BaTiO3を主成分とする厚み
1.3μmの生のセラミック層を準備し、所定枚数の生
のセラミック層の表面上に一方の端縁が生のセラミック
層の何れかの端面側に露出するように、乾燥後厚みが
0.5μmの内部電極となるべき電極膜を印刷し、これ
ら複数の生のセラミック層を所定枚数積層し圧着して、
試料1〜7の生のセラミック積層体を100個ずつ準備
した。
Subsequently, a 1.3 μm thick green ceramic layer containing BaTiO 3 as a main component is prepared, and one edge of any of the green ceramic layers is formed on the surface of a predetermined number of green ceramic layers. An electrode film to be an internal electrode having a thickness of 0.5 μm after drying is printed so as to be exposed on the end face side, and a predetermined number of these green ceramic layers are laminated and pressed.
100 raw ceramic laminates of Samples 1 to 7 were prepared.

【0037】次いで、この生のセラミック積層体を、N
2雰囲気中にて400℃で加熱して有機バインダを燃焼
させた後、酸素分圧が9×10-12MPaのH2−N2
2Oガスからなる還元性雰囲気中において1200℃
を最高焼成温度として3時間保持して、試料1〜7のセ
ラミック積層体を得た。次いで、試料1〜7のセラミッ
ク積層体の端面に露出した内部電極に電気的かつ機械的
に接合するように、Agを導電成分とする端子電極形成
用の導電性ペーストを塗布し乾燥させ、これを焼付けて
一対の端子電極を形成し、この一対の端子電極上にNi
めっき膜を電解めっき処理により形成し、さらにNiめ
っき膜上にSnめっき膜を電解めっき処理により形成し
て、試料1〜7の積層セラミックコンデンサを100個
ずつ得た。
Next, this green ceramic laminate was
After heating the organic binder at 400 ° C. in an atmosphere of 2 to burn the organic binder, an oxygen partial pressure of H 2 —N 2 — of 9 × 10 −12 MPa was obtained.
1200 ° C. in a reducing atmosphere composed of H 2 O gas
Was maintained at the maximum firing temperature for 3 hours to obtain ceramic laminates of Samples 1 to 7. Then, a conductive paste for forming a terminal electrode containing Ag as a conductive component is applied and dried so as to be electrically and mechanically joined to the internal electrodes exposed on the end faces of the ceramic laminates of Samples 1 to 7, and then dried. To form a pair of terminal electrodes, and Ni
A plated film was formed by electrolytic plating, and a Sn plated film was formed on the Ni plated film by electrolytic plating to obtain 100 multilayer ceramic capacitors of Samples 1 to 7.

【0038】そこで、試料1〜7の積層セラミックコン
デンサ100個についてショート不良の有無を測定して
ショート不良発生率を求め、これに評価を付してを表2
にまとめた。なお、評価は、本発明の範囲内となった金
属粉末ならびに導電性ペーストについては○、範囲外と
なったものについては×を付した。
Therefore, the occurrence of short-circuit failure was measured for 100 multilayer ceramic capacitors of samples 1 to 7 to determine the occurrence of short-circuit failure.
Summarized in In the evaluation, 金属 was given for metal powder and conductive paste falling within the range of the present invention, and x was given for those falling outside the range.

【0039】[0039]

【表2】 [Table 2]

【0040】表2から明らかであるように、溶媒である
水の抵抗値が1MΩcm以上であるである試料3〜7の
金属粉末を用いた積層セラミックコンデンサは、表面粗
さが59〜68nmであり、ショート不良発生率も0%
で優れ、本発明の範囲内となった。
As is apparent from Table 2, the multilayer ceramic capacitors using the metal powders of Samples 3 to 7 having a resistance value of water as a solvent of 1 MΩcm or more had a surface roughness of 59 to 68 nm. 0% short-circuit failure rate
And within the scope of the present invention.

【0041】これに対して、溶媒である水の抵抗値が1
MΩcm未満である試料1,2の金属粉末を用いた電極
膜ならびに積層セラミックコンデンサは、表面粗さが1
28〜135nmであり、ショート不良発生率は100
%で劣り、本発明の範囲外となった。
On the other hand, the resistance value of water as a solvent is 1
The electrode films and the multilayer ceramic capacitors using the metal powders of Samples 1 and 2 having a surface roughness of less than 1
28 to 135 nm, and the short-circuit defect occurrence rate is 100
% Was out of the range of the present invention.

【0042】(実施例2)実施例2では、金属粉末とし
て銅を生成し、これを用いた導電性ペースト,試験サン
プルならびに積層セラミック電子部品の一形態として積
層セラミックコンデンサを作製する。
Example 2 In Example 2, copper is produced as a metal powder, and a multilayer ceramic capacitor is produced as one form of a conductive paste, a test sample and a multilayer ceramic electronic component using the same.

【0043】まず、表2に示すように、溶媒として抵抗
率がそれぞれ0.4MΩcm,0.9MΩcm,1.1
MΩcm,2.5MΩcm,5.0MΩcm,10.0
MΩcm,17.0MΩcmである水を準備し、金属塩
である硫酸銅50gを上記水溶媒150mlに溶解して
試料8〜14の金属塩溶液を作成し、水酸化ナトリウム
3gと還元剤である水素化ホウ素ナトリウム20gを上
記水溶媒150mlに溶解して試料8〜14の還元剤溶
液を作成した。
First, as shown in Table 2, the resistivity of the solvent was 0.4 MΩcm, 0.9 MΩcm, and 1.1 MΩcm, respectively.
MΩcm, 2.5MΩcm, 5.0MΩcm, 10.0
Water having MΩcm and 17.0 MΩcm is prepared, and 50 g of copper sulfate as a metal salt is dissolved in 150 ml of the above-mentioned water solvent to prepare a metal salt solution of Samples 8 to 14, 3 g of sodium hydroxide and hydrogen as a reducing agent are prepared. 20 g of sodium borohydride was dissolved in 150 ml of the above-mentioned aqueous solvent to prepare reducing agent solutions of Samples 8 to 14.

【0044】次いで、試料8〜14の金属塩溶液と還元
剤溶液を60℃に保ち、還元剤溶液に金属塩溶液を投入
してニッケルを還元・析出させた後、これを分離・回収
し、純水ならびにアセトンで洗浄し、オーブン中で乾燥
させて、試料8〜14の金属粉末(銅)を得た。
Next, the metal salt solution and the reducing agent solution of Samples 8 to 14 were kept at 60 ° C., and the metal salt solution was added to the reducing agent solution to reduce and precipitate nickel, which was then separated and collected. After washing with pure water and acetone and drying in an oven, metal powders (copper) of Samples 8 to 14 were obtained.

【0045】そこで、試料8〜14のニッケル粉末を走
査型電子顕微鏡で観察し、デジタイザによって粒径を3
0点測定し、平均粒径と粒径の標準偏差を求め、これを
表3にまとめた。
Then, the nickel powders of Samples 8 to 14 were observed with a scanning electron microscope, and the particle size was measured with a digitizer.
The measurement was performed at 0 points, and the average particle diameter and the standard deviation of the particle diameter were obtained.

【0046】[0046]

【表3】 [Table 3]

【0047】表3から明らかであるように、試料8〜1
4の平均粒径は何れも87〜92nmの範囲内で優れた
が、溶媒である水の抵抗値が1MΩcm未満である試料
8,9の標準偏差は51〜53nmで大きいのに対し
て、水の抵抗値が1MΩcm以上である試料10〜14
の標準偏差は10〜13nmで小さいことが分かる。
As is clear from Table 3, samples 8 to 1
The average particle size of Sample No. 4 was excellent in the range of 87 to 92 nm, but the standard deviation of Samples 8 and 9 in which the resistance of water as a solvent was less than 1 MΩcm was large in the range of 51 to 53 nm. Samples 14 to 14 having a resistance value of 1 MΩcm or more
It can be seen that the standard deviation is small at 10 to 13 nm.

【0048】続いて、試料8〜14の金属粉末50重量
%と、エチルセルロース10重量部をテルピネオール9
0重量部に溶解させた有機ビヒクル40重量%と、テル
ピネオール40重量%と、を混合し3本ロールミルを用
いて混練を行ない、試料8〜14の導電性ペーストを得
た。
Subsequently, 50% by weight of the metal powder of Samples 8 to 14 and 10 parts by weight of ethylcellulose were added to terpineol 9
40 wt% of the organic vehicle dissolved in 0 wt% and 40 wt% of terpineol were mixed and kneaded using a three-roll mill to obtain conductive pastes of Samples 8 to 14.

【0049】そこで、試料8〜14の導電性ペーストを
ガラス板上に塗布厚みが1.0μmとなるように印刷し
て電極膜を形成し、触針式膜厚計を用いて電極膜の十点
表面粗さ(Rz)を測定し、これを表4にまとめた。
Therefore, the conductive pastes of Samples 8 to 14 were printed on a glass plate so as to have a coating thickness of 1.0 μm to form an electrode film, and the thickness of the electrode film was measured using a stylus-type film thickness meter. The point surface roughness (Rz) was measured and is summarized in Table 4.

【0050】続いて、BaTiO3を主成分とする厚み
1.4μmの生のセラミック層を準備し、所定枚数の生
のセラミック層の表面上に一方の端縁が生のセラミック
層の何れかの端面側に露出するように、乾燥後厚みが
0.4μmの内部電極となるべき電極膜を印刷し、これ
ら複数の生のセラミック層を所定枚数積層し圧着して、
試料8〜14の生のセラミック積層体を100個ずつ準
備した。
Subsequently, a 1.4 μm thick green ceramic layer containing BaTiO 3 as a main component is prepared, and one edge of one of the green ceramic layers is formed on the surface of a predetermined number of green ceramic layers. An electrode film to be an internal electrode having a thickness of 0.4 μm after drying is printed so as to be exposed on the end face side, and a predetermined number of these green ceramic layers are laminated and pressed.
100 raw ceramic laminates of Samples 8 to 14 were prepared.

【0051】次いで、この生のセラミック積層体を、N
2雰囲気中にて400℃で加熱して有機バインダを燃焼
させた後、酸素分圧が9×10-12MPaのH2−N2
2Oガスからなる還元性雰囲気中において1200℃
を最高焼成温度として3時間保持して、試料8〜14の
セラミック積層体を得た。次いで、試料8〜14のセラ
ミック積層体の端面に露出した内部電極に電気的かつ機
械的に接合するように、Agを導電成分とする端子電極
形成用の導電性ペーストを塗布し乾燥させ、これを焼付
けて一対の端子電極を形成し、この一対の端子電極上に
Niめっき膜を電解めっき処理により形成し、さらにN
iめっき膜上にSnめっき膜を電解めっき処理により形
成して、試料8〜14の積層セラミックコンデンサを1
00個ずつ得た。
Next, this green ceramic laminate was
After heating the organic binder at 400 ° C. in an atmosphere of 2 to burn the organic binder, an oxygen partial pressure of H 2 —N 2 — of 9 × 10 −12 MPa was obtained.
1200 ° C. in a reducing atmosphere composed of H 2 O gas
Was maintained at the highest firing temperature for 3 hours to obtain ceramic laminates of Samples 8 to 14. Then, a conductive paste for forming a terminal electrode containing Ag as a conductive component is applied and dried so as to be electrically and mechanically joined to the internal electrodes exposed on the end faces of the ceramic laminates of Samples 8 to 14, and dried. To form a pair of terminal electrodes, a Ni plating film is formed on the pair of terminal electrodes by electrolytic plating, and
An Sn plating film was formed on the i-plating film by electrolytic plating, and the multilayer ceramic capacitors of Samples 8 to 14 were formed as 1
00 pieces were obtained.

【0052】そこで、試料8〜14の積層セラミックコ
ンデンサ100個についてショート不良の有無を測定し
てショート不良発生率を求め、これに評価を付してを表
4にまとめた。なお、評価は、本発明の範囲内となった
金属粉末ならびに導電性ペーストについては○、範囲外
となったものについては×を付した。
Therefore, the occurrence of short-circuit defects was determined by measuring the presence or absence of short-circuit defects in 100 multilayer ceramic capacitors of Samples 8 to 14, and the results were evaluated. In the evaluation, 金属 was given for metal powder and conductive paste falling within the range of the present invention, and x was given for those falling outside the range.

【0053】[0053]

【表4】 [Table 4]

【0054】表4から明らかであるように、溶媒である
水の抵抗値が1MΩcm以上であるである試料10〜1
4の金属粉末を用いた積層セラミックコンデンサは、表
面粗さが47〜53nmであり、ショート不良発生率も
0%で優れ、本発明の範囲内となった。
As is clear from Table 4, Samples 10 to 1 having a resistance value of water as a solvent of 1 MΩcm or more were obtained.
The multilayer ceramic capacitor using the metal powder of No. 4 had a surface roughness of 47 to 53 nm and an excellent short-circuit defect occurrence rate of 0%, which was within the scope of the present invention.

【0055】これに対して、溶媒である水の抵抗値が1
MΩcm未満である試料8,9の金属粉末を用いた電極
膜ならびに積層セラミックコンデンサは、表面粗さが1
08〜112nmであり、ショート不良発生率は100
%で劣り、本発明の範囲外となった。
On the other hand, the resistance value of water as a solvent is 1
The electrode films and multilayer ceramic capacitors using the metal powders of Samples 8 and 9 having a surface roughness of less than 1
08 to 112 nm, and the short-circuit defect occurrence rate is 100
% Was out of the range of the present invention.

【0056】[0056]

【発明の効果】以上のように本発明によれば、抵抗率が
1MΩcm以上である水を含む溶媒に、金属塩と、還元
剤と、を含有させ、金属塩または還元剤の少なくとも一
部が溶媒中に溶解した混合液中で、還元剤の働きで金属
塩を還元させ、金属塩に含まれる金属からなる金属粉末
を析出させることを特徴とすることで、粗大粒子の存在
しない、粒径のバラツキの少ない微粒の金属粉末を提供
することができる。また、このような金属粉末を含有し
てなる導電性ペーストを用いて内部電極を形成すること
で、ショート不良のない積層セラミック電子部品を提供
することができる。
As described above, according to the present invention, a metal salt and a reducing agent are contained in a solvent containing water having a resistivity of 1 MΩcm or more, and at least a part of the metal salt or the reducing agent is contained. In a mixed solution dissolved in a solvent, a metal salt is reduced by the action of a reducing agent, and a metal powder composed of a metal contained in the metal salt is precipitated, whereby coarse particles are not present. Thus, it is possible to provide a fine metal powder having less variation. Further, by forming an internal electrode using a conductive paste containing such a metal powder, a multilayer ceramic electronic component free from short-circuit failure can be provided.

【図面の簡単な説明】[Brief description of the drawings]

【図1】本発明に係る一つの実施の形態の積層セラミッ
ク電子部品の断面図である。
FIG. 1 is a cross-sectional view of a multilayer ceramic electronic component according to one embodiment of the present invention.

【符号の説明】[Explanation of symbols]

1 積層セラミック電子部品 2 セラミック素体 2a セラミック層 3 内部電極 DESCRIPTION OF SYMBOLS 1 Multilayer ceramic electronic component 2 Ceramic body 2a Ceramic layer 3 Internal electrode

───────────────────────────────────────────────────── フロントページの続き (51)Int.Cl.7 識別記号 FI テーマコート゛(参考) H01G 4/12 361 H01G 4/12 361 4/30 301 4/30 301C Fターム(参考) 4K017 AA03 BA02 BA03 BA05 DA01 DA08 EJ01 FB07 5E001 AB03 AH01 AH09 AJ01 AJ02 5E082 AA01 AB03 EE04 EE23 LL02 5G301 DA03 DA06 DA10 DA11 DA42 DA53 DD01 ──────────────────────────────────────────────────の Continued on the front page (51) Int.Cl. 7 Identification symbol FI Theme coat ゛ (Reference) H01G 4/12 361 H01G 4/12 361 4/30 301 4/30 301C F-term (Reference) 4K017 AA03 BA02 BA03 BA05 DA01 DA08 EJ01 FB07 5E001 AB03 AH01 AH09 AJ01 AJ02 5E082 AA01 AB03 EE04 EE23 LL02 5G301 DA03 DA06 DA10 DA11 DA42 DA53 DD01

Claims (8)

【特許請求の範囲】[Claims] 【請求項1】 抵抗率が1MΩcm以上である水を含む
溶媒に、金属塩と、還元剤と、を含有させ、前記金属塩
または前記還元剤の少なくとも一部が前記溶媒中に溶解
した混合液中で、前記還元剤の働きで前記金属塩を還元
させ、前記金属塩に含まれる金属からなる金属粉末を析
出させることを特徴とする、金属粉末の製造方法。
1. A mixed solution in which a metal salt and a reducing agent are contained in a solvent containing water having a resistivity of 1 MΩcm or more, and at least a part of the metal salt or the reducing agent is dissolved in the solvent. Wherein the metal salt is reduced by the action of the reducing agent to precipitate a metal powder composed of a metal contained in the metal salt.
【請求項2】 前記還元剤溶液は、ヒドラジン,ヒドラ
ジン水和物,水素化ホウ素化合物,アミノボラザン系還
元剤よりなる群から選ばれる少なくとも1種であること
を特徴とする、請求項1に記載の金属粉末の製造方法。
2. The method according to claim 1, wherein the reducing agent solution is at least one selected from the group consisting of hydrazine, hydrazine hydrate, a borohydride compound, and an aminoborazane-based reducing agent. Production method of metal powder.
【請求項3】 前記金属塩に含まれる前記金属は、P
d,Cu,Ni,Agよりなる群から選ばれる少なくと
も1種であることを特徴とする、請求項1または2に記
載の金属粉末の製造方法。
3. The method according to claim 2, wherein the metal contained in the metal salt is P
3. The method for producing a metal powder according to claim 1, wherein the metal powder is at least one selected from the group consisting of d, Cu, Ni, and Ag.
【請求項4】 前記金属塩は、塩化物,硫酸塩および硝
酸塩よりなる群から選ばれる少なくとも1種であること
を特徴とする、請求項1〜3の何れかに記載の金属粉末
の製造方法。
4. The method for producing a metal powder according to claim 1, wherein said metal salt is at least one selected from the group consisting of chloride, sulfate and nitrate. .
【請求項5】 前記溶媒は、抵抗率が1MΩcm以上で
ある水単体、または抵抗率が1MΩcm以上である水と
アルコールとの混合溶媒であることを特徴とする、請求
項1〜4の何れかに記載の金属粉末の製造方法。
5. The solvent according to claim 1, wherein the solvent is water alone having a resistivity of 1 MΩcm or more, or a mixed solvent of water and an alcohol having a resistivity of 1 MΩcm or more. 3. The method for producing a metal powder according to item 1.
【請求項6】 請求項1〜5の何れかに記載の製造方法
によって得られたことを特徴とする、金属粉末。
6. A metal powder obtained by the production method according to claim 1.
【請求項7】 請求項6に記載の金属粉末と、有機ビヒ
クルとを含有してなることを特徴とする、導電性ペース
ト。
7. A conductive paste comprising the metal powder according to claim 6 and an organic vehicle.
【請求項8】 複数のセラミック層が積層状態にあるセ
ラミック積層体と、前記セラミック層間に形成された複
数の内部電極と、を備える積層セラミック電子部品であ
って、 前記内部電極は、請求項7に記載の導電性ペーストを用
いて形成されていることを特徴とする、積層セラミック
電子部品。
8. A multilayer ceramic electronic component comprising: a ceramic laminate in which a plurality of ceramic layers are stacked; and a plurality of internal electrodes formed between the ceramic layers, wherein the internal electrodes are A multilayer ceramic electronic component characterized by being formed using the conductive paste described in (1).
JP2001074807A 2001-03-15 2001-03-15 Method for manufacturing metal powder, metal powder, conductive paste which uses the same and multilayer ceramic electronic parts which use the same Pending JP2002275509A (en)

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Publication number Priority date Publication date Assignee Title
JP2004211108A (en) * 2002-11-12 2004-07-29 Dowa Mining Co Ltd Fine granular copper powder and its producing method
JP2004217991A (en) * 2003-01-14 2004-08-05 Dowa Mining Co Ltd Nickel-coated fine copper powder, and production method therefor
JP2009079269A (en) * 2007-09-26 2009-04-16 Dowa Electronics Materials Co Ltd Copper powder for electroconductive paste, production method therefor and electroconductive paste
JP2009124172A (en) * 2009-02-05 2009-06-04 Shoei Chem Ind Co Method of manufacturing laminated electronic component
JP2009147359A (en) * 2009-02-05 2009-07-02 Shoei Chem Ind Co Conductor paste for internal electrode of laminated electronic component and laminated electronic component using the same

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JPS60238406A (en) * 1984-05-14 1985-11-27 Tokuyama Soda Co Ltd Manufacture of hyperfine metallic powder
JPH0543921A (en) * 1991-08-12 1993-02-23 Murata Mfg Co Ltd Production of nickel fine powder
JPH05112804A (en) * 1991-10-21 1993-05-07 Sumitomo Metal Ind Ltd Production of copper powder

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JPS60238406A (en) * 1984-05-14 1985-11-27 Tokuyama Soda Co Ltd Manufacture of hyperfine metallic powder
JPH0543921A (en) * 1991-08-12 1993-02-23 Murata Mfg Co Ltd Production of nickel fine powder
JPH05112804A (en) * 1991-10-21 1993-05-07 Sumitomo Metal Ind Ltd Production of copper powder

Cited By (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2004211108A (en) * 2002-11-12 2004-07-29 Dowa Mining Co Ltd Fine granular copper powder and its producing method
JP2004217991A (en) * 2003-01-14 2004-08-05 Dowa Mining Co Ltd Nickel-coated fine copper powder, and production method therefor
JP2009079269A (en) * 2007-09-26 2009-04-16 Dowa Electronics Materials Co Ltd Copper powder for electroconductive paste, production method therefor and electroconductive paste
JP2009124172A (en) * 2009-02-05 2009-06-04 Shoei Chem Ind Co Method of manufacturing laminated electronic component
JP2009147359A (en) * 2009-02-05 2009-07-02 Shoei Chem Ind Co Conductor paste for internal electrode of laminated electronic component and laminated electronic component using the same

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