JP2007042688A - Nickel powder for internal electrode of multilayered ceramic capacitor, and multilayered ceramic capacitor formed thereof - Google Patents
Nickel powder for internal electrode of multilayered ceramic capacitor, and multilayered ceramic capacitor formed thereof Download PDFInfo
- Publication number
- JP2007042688A JP2007042688A JP2005222189A JP2005222189A JP2007042688A JP 2007042688 A JP2007042688 A JP 2007042688A JP 2005222189 A JP2005222189 A JP 2005222189A JP 2005222189 A JP2005222189 A JP 2005222189A JP 2007042688 A JP2007042688 A JP 2007042688A
- Authority
- JP
- Japan
- Prior art keywords
- nickel
- ceramic capacitor
- nickel powder
- internal electrode
- chromium
- 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
Links
Classifications
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01G—CAPACITORS; CAPACITORS, RECTIFIERS, DETECTORS, SWITCHING DEVICES OR LIGHT-SENSITIVE DEVICES, OF THE ELECTROLYTIC TYPE
- H01G4/00—Fixed capacitors; Processes of their manufacture
- H01G4/002—Details
- H01G4/005—Electrodes
- H01G4/008—Selection of materials
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01G—CAPACITORS; CAPACITORS, RECTIFIERS, DETECTORS, SWITCHING DEVICES OR LIGHT-SENSITIVE DEVICES, OF THE ELECTROLYTIC TYPE
- H01G4/00—Fixed capacitors; Processes of their manufacture
- H01G4/002—Details
- H01G4/018—Dielectrics
- H01G4/06—Solid dielectrics
- H01G4/08—Inorganic dielectrics
- H01G4/12—Ceramic dielectrics
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01G—CAPACITORS; CAPACITORS, RECTIFIERS, DETECTORS, SWITCHING DEVICES OR LIGHT-SENSITIVE DEVICES, OF THE ELECTROLYTIC TYPE
- H01G4/00—Fixed capacitors; Processes of their manufacture
- H01G4/30—Stacked capacitors
Abstract
Description
本発明は、積層セラミックコンデンサの内部電極に好適な、高温域における焼結収縮量が小さい積層セラミックコンデンサ内部電極用ニッケル粉及び該ニッケル粉からなる積層セラミックコンデンサに関するものである。 The present invention relates to nickel powder for a multilayer ceramic capacitor internal electrode, which is suitable for the internal electrode of the multilayer ceramic capacitor and has a small amount of sintering shrinkage in a high temperature range, and a multilayer ceramic capacitor comprising the nickel powder.
近年、電子機器の小型化に伴い、電子部品の小型化が急速に進行しつつある。このような状況において、積層セラミックコンデンサが小型・高容量のコンデンサとして大量に使用されている。
従来、積層セラミックコンデンサの内部電極用材料には、パラジウム、白金などの貴金属が主として使用されていた。
しかし、コンデンサの高容量化のために積層数を増加させると、上記積層セラミックコンデンサでは原料費が高騰してしまうという問題があり、このため、最近ではコスト低減のために内部電極用材料としてニッケル粉末が多用されている。
In recent years, with the miniaturization of electronic devices, the miniaturization of electronic components is rapidly progressing. Under such circumstances, multilayer ceramic capacitors are used in large quantities as small and high capacity capacitors.
Conventionally, noble metals such as palladium and platinum have been mainly used as internal electrode materials for multilayer ceramic capacitors.
However, if the number of laminated layers is increased to increase the capacity of the capacitor, there is a problem that the raw material cost increases in the multilayer ceramic capacitor. For this reason, recently, nickel has been used as an internal electrode material for cost reduction. A lot of powder is used.
かかる内部電極用材料として使用されるニッケル粉末は、一般に、バインダー中に分散させて、ペーストとして用いられる。
そして、このペーストを基板上に印刷塗布し、多層積み重ねて圧着し、還元雰囲気中で約１３００℃の温度で焼成して電極を形成させ、コンデンサとしての機能を発揮させている。
この電極の厚みは、通常、焼成後で２〜３μｍであるが、近年、コンデンサの高容量化・小型化に伴い、より薄い電極を形成させることが要求されてきた。
しかしながら、ニッケル塗膜中のニッケル粉の充填密度は、粉末冶金における充填密度に比較してはるかに低く、しかも、基板となるセラミックグリーンシートの焼結に伴う収縮量がニッケル電極膜に比較して小さいために、焼結の進行に伴って、ニッケル膜が島状に途切れるという問題が発生することとなった。
この傾向は、大きな収縮率の差によって電極の塗膜厚が薄くなるほど顕著となり、電極が途切れた場合は、コンデンサとして機能しなくなるため、コンデンサの小型・高容量化のためには、焼結による収縮が小さく、電極途切れが発生しにくいニッケル粉末の開発が待望されている。
The nickel powder used as the internal electrode material is generally dispersed in a binder and used as a paste.
This paste is printed and applied onto a substrate, stacked in layers, and bonded, and baked in a reducing atmosphere at a temperature of about 1300 ° C. to form an electrode, thereby functioning as a capacitor.
The thickness of this electrode is usually 2 to 3 μm after firing, but in recent years, it has been required to form a thinner electrode with the increase in capacity and size of the capacitor.
However, the packing density of nickel powder in the nickel coating is much lower than the packing density in powder metallurgy, and the amount of shrinkage associated with the sintering of the ceramic green sheet that is the substrate is lower than that of the nickel electrode film. Due to the small size, the problem that the nickel film was cut into islands with the progress of sintering occurred.
This tendency becomes more prominent as the electrode coating thickness becomes thinner due to the large difference in shrinkage rate. When the electrode is interrupted, it does not function as a capacitor. The development of nickel powder that is small in shrinkage and less likely to cause electrode breakage is awaited.
上記課題を解決するため、例えば特許文献１に記載されているように、ニッケルペーストに誘電体セラミック粉末（共材）を加えることでニッケル電極の収縮と誘電体シートの収縮の差（ミスマッチ）を吸収している。
しかしながら、最近ではより薄い電極を得るために、使用されるニッケル粉の粒子径は微粒化する方向にあり、ニッケル粒子間の隙間（スリーポケット）の大きさもそれにつれて小さくなっているため、市販されている０．１μｍ以上の共材ではスリーポケットに収まりきらず、それ故ニッケル粒子の初期充填密度を低下させてしまうため、焼結時の収縮率を低減させる効果が半減してしまうという問題があった。
In order to solve the above problem, for example, as described in Patent Document 1, a dielectric ceramic powder (co-material) is added to a nickel paste to reduce the difference (mismatch) between the contraction of the nickel electrode and the contraction of the dielectric sheet. Absorbs.
However, recently, in order to obtain thinner electrodes, the particle diameter of the nickel powder used is in the direction of atomization, and the size of the gap between the nickel particles (three pockets) has also become smaller accordingly, so it is commercially available. However, the co-material of 0.1 μm or more does not fit in the three pockets, and therefore the initial packing density of nickel particles is lowered, so that the effect of reducing the shrinkage rate during sintering is halved. It was.
また、特許文献２に記載の方法においては、複合酸化物を形成することのできる各々の熱分解性化合物とニッケル原料とを含む溶液を噴霧し、熱分解して複合酸化物を含んだニッケル粉末を調製している。
しかし、この方法では複合酸化物の被覆状態が均一なものを得るのが難しく、焼結の進行が均一に行われないため薄く、均一な電極を得るには限界があった。
更に、特許文献３に記載の方法は、ニッケル粉末を水溶液中でチタン酸バリウム前駆体被覆し、乾燥後４００℃以上の温度で加熱し、チタン酸バリウム被覆ニッケル粉を得る方法であるが、この方法によるとチタン酸バリウム前駆体がニッケル粒子同士のバインダーとなり乾燥時に強固に凝集し、更にこれを熱処理することで凝集は更に強固なものとなるため、薄く均一な電極を得る材料として有効に用いられるまでには至っていなかった。
また、特許文献４では、クロムなどの金属塩をニッケル塩化物とともに揮発させ、気中還元することにより球状の合金粉を得ている。そして、これによればニッケル粉自身の焼結開始温度を高温側にシフトさせることができるが、それでも収縮の開始する温度が５４０℃程度であり、それ以上の温度域においては合金化されていないニッケル粉と同等の収縮率を示している。
このため、チタン酸バリウムを主成分とするセラミックシートの収縮は１０００℃以上で顕著となるため、収縮の前記したミスマッチを完全に解消するには至っていなかった。
Further, in the method described in Patent Document 2, a nickel powder containing a composite oxide by spraying a solution containing each thermally decomposable compound capable of forming a composite oxide and a nickel raw material and thermally decomposing the solution. Has been prepared.
However, in this method, it is difficult to obtain a composite oxide with a uniform coating state, and since the progress of sintering is not performed uniformly, there is a limit to obtain a thin and uniform electrode.
Furthermore, the method described in Patent Document 3 is a method in which nickel powder is coated with a barium titanate precursor in an aqueous solution and heated at a temperature of 400 ° C. or higher after drying to obtain barium titanate-coated nickel powder. According to the method, the barium titanate precursor becomes a binder between nickel particles and aggregates strongly when dried, and further heat-treats this to further strengthen the aggregation, so it is effectively used as a material to obtain a thin and uniform electrode. It was not reached.
Moreover, in patent document 4, spherical alloy powder is obtained by volatilizing metal salts, such as chromium, with nickel chloride, and reducing in air | atmosphere. And according to this, although the sintering start temperature of nickel powder itself can be shifted to a high temperature side, the temperature at which shrinkage starts still is about 540 ° C., and is not alloyed in a temperature range higher than that. The shrinkage rate is equivalent to that of nickel powder.
For this reason, the shrinkage of the ceramic sheet mainly composed of barium titanate becomes remarkable at 1000 ° C. or higher, and thus the above-described mismatch of shrinkage has not been completely eliminated.
本発明者らは鋭意検討した結果、積層セラミックコンデンサの誘電体材料として使用されるチタン酸バリウムは、１０００℃以上の高温域で焼結し、大きな収縮を示すことから、従来は、該積層セラミックコンデンサを設計する際、かかる収縮挙動にあわせるべく、収縮の開始温度をより高温側へシフトさせることが望ましいとされてきたが、本発明者らは、高温域における収縮率を小さく抑えることがより重要であることを見出した。というのも、ニッケル粉自体の収縮が小さければ、その収縮挙動は添加されるもの（本発明の場合にはクロム）の焼結・収縮挙動に支配されるため誘電体シートの収縮挙動に近づけることがより容易になるからである。
このように、本発明者らは、クロムを含有した微粒の酸化ニッケルを添加したニッケル粉は、１０００℃以上の高温域においても収縮が極めて小さくなることを見出し、本発明を完成させた。
As a result of intensive studies, the present inventors have shown that barium titanate used as a dielectric material of a multilayer ceramic capacitor sinters at a high temperature range of 1000 ° C. or higher and exhibits large shrinkage. When designing a capacitor, it has been desirable to shift the shrinkage start temperature to a higher temperature side in order to match such shrinkage behavior, but the present inventors have suppressed the shrinkage rate in a high temperature range to be small. I found it important. This is because if the shrinkage of the nickel powder itself is small, the shrinkage behavior is governed by the sintering / shrinkage behavior of the added material (chromium in the case of the present invention), so that it approaches that of the dielectric sheet. This is because it becomes easier.
Thus, the present inventors have found that the nickel powder to which fine nickel oxide containing chromium is added exhibits extremely small shrinkage even in a high temperature range of 1000 ° C. or higher, and completed the present invention.
即ち、クロムを含有する酸化ニッケルは水素により還元されにくくなる。そのため、ニッケルペーストを還元雰囲気で焼成する際に、クロムを含有する微粒酸化ニッケルが存在すると、この酸化ニッケルがニッケル粉同士の焼結を立体的に阻害する。この挙動は、チタン酸バリウム系の共材と同じ効果といえるが、１０００℃以上の高温域では共材として用いられる微粒チタン酸バリウム同士が焼結し、これがニッケルとの濡れ性の悪さにより電極表面に浮き上がるという現象が発生する。チタン酸バリウム共材は電極内部から表面に浮き上がった時点でその焼結抑制効果を失うため、ニッケル電極は急激に収縮することになる。これに対し、クロムを含有する酸化ニッケルは、９００℃でその表面のみが還元されるためニッケルとの濡れ性が良く、電極内部に留まり続ける。その後、還元が進むに従ってクロムがニッケル電極に拡散し、最終的にニッケルクロム合金となるため、前述の電極表面に浮かび上がるというような現象が起こらず、従って急激な収縮も起こらないためクラック及び電極途切れを防止できるという優れた効果を得ることができる。本発明者はこれらの点に着目し、本発明を採用するに至ったのである。 That is, nickel oxide containing chromium is difficult to be reduced by hydrogen. Therefore, when nickel paste containing chromium is present when the nickel paste is fired in a reducing atmosphere, the nickel oxide sterically hinders the sintering of the nickel powders. This behavior can be said to be the same effect as the barium titanate-based co-material, but in the high temperature range of 1000 ° C. or higher, the fine barium titanate used as the co-material sinters, and this is due to the poor wettability with nickel The phenomenon of floating on the surface occurs. Since the barium titanate co-material loses its sintering suppression effect when it floats on the surface from the inside of the electrode, the nickel electrode contracts rapidly. On the other hand, nickel oxide containing chromium has good wettability with nickel because only its surface is reduced at 900 ° C., and remains in the electrode. After that, as the reduction proceeds, chromium diffuses into the nickel electrode and finally becomes a nickel-chromium alloy, so that the phenomenon of rising above the electrode surface does not occur, and therefore no rapid contraction occurs, so cracks and electrodes An excellent effect of preventing breakage can be obtained. The present inventor has focused on these points and has come to adopt the present invention.
このため、本発明の目的は、高温域における焼結収縮率を小さくし、積層セラミックコンデンサの製造工程において発生する、クラック及び電極途切れを防止できる積層セラミックコンデンサ内部電極用ニッケル粉及び該ニッケル粉からなる積層セラミックコンデンサを提供することにある。 For this reason, the object of the present invention is to reduce the sintering shrinkage rate in the high temperature range and prevent cracks and electrode breaks that occur in the manufacturing process of the multilayer ceramic capacitor. An object of the present invention is to provide a multilayer ceramic capacitor.
本発明に係る積層セラミックコンデンサ内部電極用ニッケル粉は、ニッケル化合物に対しクロムを０．３〜１５重量％添加して得られたクロム含有微粒酸化ニッケルを主成分とすることを特徴とするものである。
また、本発明に係る他の積層セラミックコンデンサ内部電極用ニッケル粉は、前記クロム含有微粒酸化ニッケルのＴＥＭ平均粒子径が０．３μｍ以下であることを特徴とするものである。
更に、本発明の他の積層セラミックコンデンサ内部電極用ニッケル粉は、酸素含有量が１〜１０重量％であることを特徴とするものである。
また、本発明の積層セラミックコンデンサは、上記積層セラミックコンデンサ内部電極用ニッケル粉を用いたことを特徴とするものである。
The nickel powder for a multilayer ceramic capacitor internal electrode according to the present invention is characterized by comprising chromium-containing fine nickel oxide obtained by adding 0.3 to 15% by weight of chromium to a nickel compound as a main component. is there.
Another nickel powder for an internal electrode of a multilayer ceramic capacitor according to the present invention is characterized in that a TEM average particle diameter of the chromium-containing fine nickel oxide is 0.3 μm or less.
Furthermore, another nickel powder for an inner electrode of a multilayer ceramic capacitor according to the present invention is characterized in that the oxygen content is 1 to 10% by weight.
The multilayer ceramic capacitor of the present invention is characterized by using the above-mentioned nickel powder for multilayer ceramic capacitor internal electrodes.
本発明に係る積層セラミックコンデンサ内部電極用ニッケル粉によれば、分散性が高く、しかも、高温域における焼結収縮率を小さく抑えることのできるクロム含有微粒酸化ニッケルを得ることができるので、製造時に発生するクラックや電極途切れを防止した積層セラミックコンデンサを得ることが可能である。 According to the nickel powder for a multilayer ceramic capacitor internal electrode according to the present invention, it is possible to obtain chromium-containing fine nickel oxide that is highly dispersible and that can suppress the sintering shrinkage rate in a high temperature range. It is possible to obtain a multilayer ceramic capacitor in which generated cracks and electrode breakage are prevented.
本発明において、ニッケル化合物に対するクロムの含有率は０．３〜１５重量％とすることが必要である。クロムの含有率が０．３重量％より少ないと、前記したクラックおよび電極途切れを防止できる効果が少ないため好ましくなく、また、クロムの含有率が１５重量％を超えると焼結抑制効果が強くなりすぎて焼結しなくなるため好ましくないからである。尚、後記する実施例においては、ニッケル化合物の１例として塩化ニッケル６水和物を挙げているが、本発明においては必ずしもこれに限定されないことはいうまでもない。
また、本発明において、クロム含有微粒酸化ニッケルのＴＥＭ平均粒子径は、０．３μｍ以下であることが好ましい。該クロム含有微粒酸化ニッケルのＴＥＭ平均粒子径が０．３μｍを超えて大きいと、内部電極膜表面中に突起となってしまい、表面粗さを悪化させ、ショート不良となるため好ましくないからである。
更に、本発明において、酸化ニッケル微粒子の平均粒径は、０．３μｍ以下が望ましい。本発明の目的としている内部電極の薄層化を達成するためには、平均粒子径は小さいほうが好ましいからである。
尚、下限の粒径としては特に規定しないが、あまりに粒径が小さいとペースト粘度が大幅に増加してしまう等の問題が発生し、取扱いが難しくなることがある。そのため０．０５μｍ以上がより望ましい。
また、本発明に係るニッケル粉の酸素含有量は１〜１０重量％であることが好ましい。該ニッケル粉の酸素含有量が１重量％より少ないと、酸化ニッケルの存在量が少なく、焼結抑制効果が充分でなくなり好ましくなく、一方、該ニッケル粉の酸素含有量が１０重量％を超えてしまうと、酸化ニッケルがニッケルに還元される際に収縮量が大きくなるため好ましくないからである。
In the present invention, the chromium content with respect to the nickel compound needs to be 0.3 to 15% by weight. If the chromium content is less than 0.3% by weight, the effect of preventing the above-described cracks and electrode breakage is small, which is not preferable. If the chromium content exceeds 15% by weight, the sintering suppression effect becomes strong. This is because it is not preferable because it is too sintered. In the examples described later, nickel chloride hexahydrate is cited as an example of the nickel compound, but it goes without saying that the present invention is not necessarily limited thereto.
In the present invention, the TEM average particle diameter of the chromium-containing fine nickel oxide is preferably 0.3 μm or less. This is because if the TEM average particle diameter of the chromium-containing fine nickel oxide exceeds 0.3 μm, it becomes undesirably because protrusions are formed in the surface of the internal electrode film, the surface roughness is deteriorated, and short-circuit defects are caused. .
Furthermore, in the present invention, the average particle diameter of the nickel oxide fine particles is preferably 0.3 μm or less. This is because the average particle diameter is preferably small in order to achieve the thinning of the internal electrode, which is the object of the present invention.
The lower limit particle size is not particularly specified, but if the particle size is too small, problems such as a significant increase in paste viscosity may occur and handling may be difficult. Therefore, 0.05 μm or more is more desirable.
Moreover, it is preferable that the oxygen content of the nickel powder which concerns on this invention is 1 to 10 weight%. When the oxygen content of the nickel powder is less than 1% by weight, the presence of nickel oxide is small and the sintering suppressing effect is not sufficient, which is not preferable. On the other hand, the oxygen content of the nickel powder exceeds 10% by weight. This is because the amount of shrinkage increases when nickel oxide is reduced to nickel, which is not preferable.
本発明を実施例及び比較例によって更に詳しく説明する。
［実施例１〜７］
The present invention will be described in more detail with reference to examples and comparative examples.
[Examples 1 to 7]
１００ｇの試薬塩化ニッケル６水和物と、表１に従った実施例１〜７の添加量に基づいた塩化クロム６水和物を純水４００ｍｌに溶解し、５５度に加温し、試薬水酸化ナトリウム水溶液（２４ｗｔ％）９５ｍｌを添加してクロム含有水酸化ニッケルを生成させた。生成した水酸化ニッケルをろ過し１リットルの純水で水洗した。ろ過水洗を４回繰り返し後、１００度で一昼夜大気乾燥を行い得られた乾燥物を乳鉢で解砕して水素気流中にて表１に示した温度で１時間、還元を行い、ニッケル粉末を得た。
［比較例１］
100 g of reagent nickel chloride hexahydrate and chromium chloride hexahydrate based on the addition amount of Examples 1 to 7 according to Table 1 were dissolved in 400 ml of pure water, heated to 55 degrees, and reagent water 95 ml of aqueous sodium oxide solution (24 wt%) was added to produce chromium-containing nickel hydroxide. The produced nickel hydroxide was filtered and washed with 1 liter of pure water. After washing with filtered water four times, the dried product obtained by drying in air at 100 degrees all day and night was crushed in a mortar and reduced in a hydrogen stream at the temperature shown in Table 1 for 1 hour to obtain nickel powder. Obtained.
[Comparative Example 1]
１００ｇの試薬塩化ニッケル６水和物を純水２５０ｍｌに溶解させ５５度に加温した。さらに試薬水酸化ナトリウム水溶液（２４ｗｔ％）９５ｍｌを添加して水酸化ニッケルを生成させた。生成した水酸化ニッケルをろ過し１リットルの純水で水洗した。ろ過水洗を４回繰り返し後、１００℃で一昼夜大気乾燥を行い得られた乾燥物を乳鉢で解砕して水素気流中にて表１に示した温度で1時間、還元を行い、ニッケル粉末を得た。
［比較例２〜３］
100 g of reagent nickel chloride hexahydrate was dissolved in 250 ml of pure water and heated to 55 degrees. Further, 95 ml of a reagent sodium hydroxide aqueous solution (24 wt%) was added to produce nickel hydroxide. The produced nickel hydroxide was filtered and washed with 1 liter of pure water. After washing with filtered water four times, the dried product obtained by air drying at 100 ° C all day and night was crushed in a mortar and reduced in a hydrogen stream at the temperature shown in Table 1 for 1 hour to obtain nickel powder. Obtained.
[Comparative Examples 2-3]
１００ｇの試薬塩化ニッケル６水和物に比較例２〜３に従った添加量に基づいた塩化クロム６水和物を純水４００ｍｌに溶解し、５５度に加温し、試薬水酸化ナトリウム水溶液（２４ｗｔ％）９５ｍｌを添加してクロム含有水酸化ニッケルを生成させた。生成した水酸化ニッケルをろ過し１リットルの純水で水洗した。ろ過水洗を４回繰り返し後、１００度で一昼夜大気乾燥を行い得られた乾燥物を乳鉢で解砕して水素気流中にて表１に示した温度で１時間、還元を行い、ニッケル粉末を得た。
［比較例４］
Chromium chloride hexahydrate based on the addition amount according to Comparative Examples 2-3 was dissolved in 100 g of reagent nickel chloride hexahydrate in 400 ml of pure water, heated to 55 ° C., and reagent sodium hydroxide aqueous solution ( 24 wt%) 95 ml was added to produce chromium-containing nickel hydroxide. The produced nickel hydroxide was filtered and washed with 1 liter of pure water. After washing with filtered water four times, the dried product obtained by drying in air at 100 degrees all day and night was crushed in a mortar and reduced in a hydrogen stream at the temperature shown in Table 1 for 1 hour to obtain nickel powder. Obtained.
[Comparative Example 4]
ニッケル換算濃度２５ｇ／リットルの塩化ニッケル溶液４リットルに水酸化ナトリウム１００ｇと６０％濃度の抱水ヒドラジン４００ｍｌを加え、攪拌保持し７０℃でニッケルを還元した。このようにして得られたニッケル粉末粒子をろ過・水洗後、１００度で一昼夜大気乾燥を行い、ニッケル粉末を得た。 100 g of sodium hydroxide and 400 ml of hydrazine hydrate having a concentration of 60% were added to 4 liters of a nickel chloride solution having a nickel equivalent concentration of 25 g / liter, and the nickel was reduced at 70 ° C. with stirring. The nickel powder particles thus obtained were filtered and washed with water, and then air-dried at 100 degrees all day and night to obtain nickel powder.
以上の条件で作成したニッケル粉について、以下の通り、分析及び評価した。
（１） クロム含有量、酸素含有量の分析
ＴＥＭ−ＥＤＸにて組成物測定を行い、クロムの含有量、酸素含有量を求めた。
（２）平均粒径
得られたニッケル粉末について、走査電子顕微鏡で粉末像を１００００倍の倍率にて１００個以上の粒子数の粒径測定を行い、その平均値から、粉末平均粒径を求めた。
（３）収縮率
焼結性改善の評価として、得られた粉末を０．３ｇ採取し、１ｔ/ｃｍ２圧力下で直径５ｍｍの圧粉体を作製した。この圧粉体を不活性雰囲気下にて、１０℃／ｍｉｎの昇速度温にて１２００℃まで昇温、炉冷し、圧粉体の線収縮率を下記する数式1に基づいて算出した。
［数式１］
線収縮率（％）＝（焼成前厚み―焼成後厚み）／焼成前厚み
（４）被覆率測定
本発明による焼結遅延効果が得られる場合、ニッケルの焼結が高温側にシフトすることになる。その結果として、クロムを添加しない場合と比較してニッケルの過焼結が抑制され、内部電極の途切れの発生が抑制される。
上記の効果を以下の方法で評価した。
本発明のニッケル粉などをペースト化、アルミナ基板に印刷した膜を焼成して得られた膜の被覆率を測定した。すなわち、被覆率が大きいほどニッケル電極の面積が大きいためコンデンサの容量が大きく確保できる訳である。
具体的な条件は以下のとおりである。
生成したニッケル粉末１００重量部に対してエチルセルロース１０重量部、ターピネオール９０重量部からなる有機ビヒクルを５０重量部添加し、三本ロールミルにて混練を行い、ニッケルペーストを作製した。作製したニッケルペーストをアルミナ基板上に１０mm角のパターンにてスクリーン印刷し、０．８mg／ｃｍ２となるニッケル塗布重量の乾燥膜を作製した。
作製したアルミナ基板を弱還元性雰囲気中、１０℃/ｍｉｎの昇温速度にて１，２００℃まで焼成を行った。その後、焼成したアルミナ基板裏側より光をあて、その透過光面積について、全測定面積との割合を算出し、下記する数式２に基づいてニッケル被覆率（％）を求めた。
［数式２］
被覆率（％）＝１−（透過光透過面積）／（観察有効面積）
（５）表面粗さＲａ
（４）にて作製したニッケルペーストを、ガラス基板上に１０ｍｍ角のパターンにてスクリーン印刷し、８０℃で２時間乾燥させ、乾燥膜厚１ミクロンのＮｉペースト乾燥膜を得た。得られたＮｉペースト乾燥膜を表面粗さ計にて表面粗さ測定を行い、表面粗さＲａを求めた。
The nickel powder prepared under the above conditions was analyzed and evaluated as follows.
(1) Analysis of chromium content and oxygen content The composition was measured by TEM-EDX, and the chromium content and the oxygen content were determined.
(2) Average particle diameter About the obtained nickel powder, a powder image is measured with a scanning electron microscope at a magnification of 10,000 times to measure the particle diameter of 100 or more particles, and the average particle diameter is obtained from the average value. It was.
(3) Shrinkage ratio As an evaluation for improving the sinterability, 0.3 g of the obtained powder was sampled to produce a green compact having a diameter of 5 mm under 1 t / cm 2 pressure. The green compact was heated to 1200 ° C. at a temperature increase rate of 10 ° C./min in an inert atmosphere and cooled in a furnace, and the linear shrinkage rate of the green compact was calculated based on Equation 1 below.
[Formula 1]
Linear shrinkage rate (%) = (thickness before firing−thickness after firing) / thickness before firing (4) Coverage measurement When the sintering delay effect according to the present invention is obtained, the sintering of nickel is shifted to the high temperature side. Become. As a result, compared with the case where chromium is not added, oversintering of nickel is suppressed, and occurrence of breakage of the internal electrode is suppressed.
The above effects were evaluated by the following methods.
The coverage of the film obtained by pasting the nickel powder of the present invention into a paste and firing the film printed on the alumina substrate was measured. That is, the larger the coverage, the larger the area of the nickel electrode, so that the capacity of the capacitor can be secured.
Specific conditions are as follows.
50 parts by weight of an organic vehicle consisting of 10 parts by weight of ethyl cellulose and 90 parts by weight of terpineol was added to 100 parts by weight of the produced nickel powder, and kneaded by a three-roll mill to prepare a nickel paste. The produced nickel paste was screen-printed on a 10 mm square pattern on an alumina substrate to produce a dry film having a nickel coating weight of 0.8 mg / cm 2 .
The produced alumina substrate was baked to 1,200 ° C. at a temperature increase rate of 10 ° C./min in a weakly reducing atmosphere. Thereafter, light was applied from the back side of the baked alumina substrate, and the ratio of the transmitted light area to the total measurement area was calculated, and the nickel coverage (%) was obtained based on the following Equation 2.
[Formula 2]
Coverage (%) = 1− (transmitted light transmission area) / (observation effective area)
(5) Surface roughness Ra
The nickel paste produced in (4) was screen-printed on a glass substrate with a 10 mm square pattern and dried at 80 ° C. for 2 hours to obtain a dried Ni paste film having a dry film thickness of 1 micron. The obtained Ni paste dry film was subjected to surface roughness measurement with a surface roughness meter to determine the surface roughness Ra.
実施例および比較例について下記する表１にその結果を示す。 The results are shown in Table 1 below for Examples and Comparative Examples.
表１の結果から、本発明の範囲であるクロム含有量が０．３％〜１５％で，粒径が０．０５〜０．２μｍの場合は、クロムを添加していない場合、或いは含有量が規定の範囲外のクロムの場合と比べ、低い収縮率、低い表面粗さであり、且つ、より高い被覆率を有しており、積層セラミックコンデンサの内部電極用材料として好適であることが分かる。
From the results of Table 1, when the chromium content, which is the scope of the present invention, is 0.3% to 15% and the particle size is 0.05 to 0.2 μm, the chromium content is not added, or the content Compared to the case of chromium outside the specified range, it has a low shrinkage rate, a low surface roughness, and a higher coverage, which is suitable as a material for an internal electrode of a multilayer ceramic capacitor. .
Claims (4)
A multilayer ceramic capacitor comprising the multilayer ceramic capacitor internal electrode nickel powder according to any one of claims 1 to 3.
Priority Applications (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2005222189A JP2007042688A (en) | 2005-07-29 | 2005-07-29 | Nickel powder for internal electrode of multilayered ceramic capacitor, and multilayered ceramic capacitor formed thereof |
| KR1020060010652A KR100790435B1 (en) | 2005-07-29 | 2006-02-03 | Nickel-powder for internal electrode of multi-layered ceramic condenser and multi-layered ceramic condenser comprising the nickel-powder |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2005222189A JP2007042688A (en) | 2005-07-29 | 2005-07-29 | Nickel powder for internal electrode of multilayered ceramic capacitor, and multilayered ceramic capacitor formed thereof |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| JP2007042688A true JP2007042688A (en) | 2007-02-15 |
Family
ID=37800426
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP2005222189A Pending JP2007042688A (en) | 2005-07-29 | 2005-07-29 | Nickel powder for internal electrode of multilayered ceramic capacitor, and multilayered ceramic capacitor formed thereof |
Country Status (2)
| Country | Link |
|---|---|
| JP (1) | JP2007042688A (en) |
| KR (1) | KR100790435B1 (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2010059467A (en) * | 2008-09-03 | 2010-03-18 | Sumitomo Metal Mining Co Ltd | Nickel powder and method for producing the same |
Family Cites Families (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US5319517A (en) | 1992-03-27 | 1994-06-07 | Tdk Corporation | Multilayer ceramic chip capacitor |
| JP2002060877A (en) | 2000-08-16 | 2002-02-28 | Kawatetsu Mining Co Ltd | Ni ALLOY POWDER FOR ELECTRICALLY CONDUCTIVE PASTE |
| CA2359347A1 (en) * | 2001-10-18 | 2003-04-18 | Cesur Celik | Laminated ceramic capacitor internal electrode material |
-
2005
- 2005-07-29 JP JP2005222189A patent/JP2007042688A/en active Pending
-
2006
- 2006-02-03 KR KR1020060010652A patent/KR100790435B1/en not_active IP Right Cessation
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2010059467A (en) * | 2008-09-03 | 2010-03-18 | Sumitomo Metal Mining Co Ltd | Nickel powder and method for producing the same |
Also Published As
| Publication number | Publication date |
|---|---|
| KR100790435B1 (en) | 2008-01-02 |
| KR20070014933A (en) | 2007-02-01 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| KR100371301B1 (en) | Monolithic Ceramic Electronic Component | |
| US6632524B1 (en) | Nickel powder, method for preparing the same and paste for use in making electrodes for electronic parts | |
| JP7176227B2 (en) | Conductive paste, electronic parts and laminated ceramic capacitors | |
| KR101151118B1 (en) | Barium titanate powder, nickel paste, their production methods and monolithic ceramic capacitors | |
| JP2010053409A (en) | Method for producing metal powder, metal powder, electrically conductive paste, and multilayer ceramic capacitor | |
| WO2020137290A1 (en) | Conductive paste, electronic component, and laminated ceramic capacitor | |
| KR20100047881A (en) | Nickel powder or alloy powder having nickel as main component, method for manufacturing the powder, conductive paste and laminated ceramic capacitor | |
| JP2010067418A (en) | Conductive paste and method of manufacturing the same | |
| JP2011091083A (en) | Multilayer ceramic electronic component and method of manufacturing the same, flat conductive fine powder for multilayer ceramic electronic component, and flat conductive fine powder dispersant liquid for multilayer ceramic electronic component | |
| JP4303715B2 (en) | Conductive paste and method for manufacturing multilayer electronic component | |
| JP5206246B2 (en) | Nickel powder and method for producing the same | |
| WO2020166361A1 (en) | Electroconductive paste, electronic component, and laminated ceramic capacitor | |
| JPWO2008041541A1 (en) | Nickel-rhenium alloy powder and conductor paste containing the same | |
| JP2005167290A (en) | Method of manufacturing laminated ceramic electronic component | |
| JP3473548B2 (en) | Method for producing metal powder, metal powder, conductive paste using the same, and multilayer ceramic electronic component using the same | |
| JP2009013490A (en) | Nickel powder, and method for producing the same | |
| JP7206671B2 (en) | Conductive paste, electronic parts and laminated ceramic capacitors | |
| JP4914065B2 (en) | Nickel powder for multilayer ceramic capacitor electrode, electrode forming paste and multilayer ceramic capacitor | |
| JP2007042688A (en) | Nickel powder for internal electrode of multilayered ceramic capacitor, and multilayered ceramic capacitor formed thereof | |
| JP2008103522A (en) | Conductive paste for multilayer ceramic component, and manufacturing method therefor | |
| JP2007332446A (en) | Nickel particle with dielectric particle and method of producing the nickel particle with dielectric particle | |
| JP2009024204A (en) | Carbide-coated nickel powder and method for producing the same | |
| JP2013149855A (en) | Conductive paste for multilayer ceramic capacitor and multilayer ceramic capacitor | |
| TW202119441A (en) | Electrically conductive paste composition for laminated ceramic capacitor internal electrode, method for manufacturing said electrically conductive paste composition for laminated ceramic capacitor internal electrode, and electrically conductive paste | |
| JP2003317542A (en) | Conductive paste and multilayer ceramic electronic component |