JP3630205B2 - Method for manufacturing dielectric ceramic material - Google Patents

Description

【００３２】
表１の実施例１は、副成分の一次粒子の平均粒径（凍結乾燥後の平均粒径）０．０３μｍのものについて、１００個について試験した結果である。また、表１の比較例１、２は、副成分の一次粒子の平均粒径０．１μｍのものについて、１００個について試験した結果である。表１の従来例は、平均粒径１．０μｍのものについて、１００個について試験した結果である。
【００３３】
また、図４の実施例１は、副成分の一次粒子の平均粒径０．０３μｍのものについての試験結果であり、図４の比較例１は、副成分の一次粒子の平均粒径０．１μｍのものについての試験結果であり、図４の従来例は、副成分の一次粒子の平均粒径１．０μｍのものについての試験結果である。
【００３４】
表１から明らかなように、実施例１によれば、従来例に比較し、ショート不良率で約１／２４０以下と減少し、比較例１、２と比較しても１／１０に減少している。また、高温負荷試験での寿命も実施例１によれば従来例、比較例１、２に比較して約６〜２４０倍以上に長くなっている。また、図４の実施例１のように、プラズマ処理後凍結乾燥する場合、平均粒径を小さくすれば、高温加速寿命試験の結果やショート不良試験において良好な結果が得られる。
【００３５】
プラズマ法を採用する実施例１において、平均粒径が０．１５μｍの場合、平均粒径が０．２μｍの場合に比較し、ショート不良率が約１／６に減少し、加速寿命が倍に伸びた。また、平均粒径が０．００１μｍ〜０．１５μｍの範囲において、ショート不良の発生率は、平均粒径が小さい程低くなると共に、加速寿命も長くなる。一方、平均粒径が０．００１μｍ未満になると、凝集が起き易くなり、製造も困難となるので、一次粒子の平均粒径が０．００１μｍ〜０．１５μｍであることが好ましい。
【００３６】
参考資料３は、それぞれ従来法、実施例１、比較例１による場合の粒子の分散状態を示す。参考資料３において、右端に示すプラズマ法について示すものは、前記実施例１において、平均粒径０．０３μｍの副成分を主成分に混合した後の元素の濃度分布を示したものである。また、焙焼法について示すものは、前記焙焼による方法で得られた平均粒径０．１μｍの副成分を、主成分に混合した後のＣａとＳｉ元素の濃度分布を示したものである。従来法（ＳＴＤ）は、前記従来例で示した副成分を主成分に混合して得たものである。参考資料３から明らかなように、プラズマ法による場合には、副成分の各粒子が各元素の混入された非晶質であることにより、粒子集合全体として各元素が均一に存在した状態にすることができる。また、焙焼法による場合は、副成分の各粒子が、各元素の化合物として存在することにより、プラズマ法と同様に、粒子集合全体として各元素が均一に分布する状態を得ることができる。いずれも従来法による場合に比較し、きめの細かな均一の成分分布が得られ、ショート不良の減少、特性の安定化が達成できる。
【００３７】
また、参考資料４は、前記実施例１において、一次粒子の平均粒径０．０３μｍ（ＢＥＴ値３０ｍ２／ｇ）の副成分を用い、内部電極間の誘電体層の厚みを７μｍ、４μｍ、２μｍに変化させた場合の電子顕微鏡によるＣＯＭＰ写真である。
【００３８】
【発明の効果】
本発明は、ＢａＴｉＯ_３、ＣａＴｉＯ_３、ＳｒＴｉＯ_３あるいはＢａＺｒＯ_３のうちの１種類または２種類以上を主成分とし、該主成分に混合する副成分として、Ｂａ、Ｃａ、Ｓｒ、Ｍｇ、Ｓｉ、Ｃｒ、Ｙ、Ｖ、Ｍｎ、Ｗ、Ｚｒの各々の化合物から選ばれる少なくとも３種以上の化合物を含むものを用い、前記副成分を混合し、粉砕した後に顆粒を作製し、該副成分の顆粒を、２０００℃〜２００００℃のプラズマ炎でガス流とした後冷却することにより、平均粒径が０．００１μｍ〜０．１５μｍの超微粒子にし、該超微粒子を湿式粉砕した後、凍結乾燥を行い、該凍結乾燥後の副成分粉末を前記主成分に対して０．２ｗｔ％以上、１０．０ｗｔ％以下混合して誘電体セラミック材料を製造する製造方法であり、プラズマ法により副成分の超微粒子を得られる上、凍結乾燥によって乾燥するため、副成分の凝集を防止することができ、超微粒子の状態を維持することができる。このため、副成分の主成分に対する分散性を良くし、組成を均一化することにより、偏析相の発生を抑え、誘電体層間厚みが１０μｍ以下であっても、ショート不良がなく、経年変化による特性劣化が少なく、小型で高静電容量、低コスト、高信頼性の積層セラミックコンデンサを作ることができる。
【００３９】
また、副成分の顆粒を作製した後、プラズマ法によって平均粒径を０．００１μｍ以上、０．１５μｍ以下の超微粒子化を得るようにしたので、副成分の一部または全部を非晶質とすることができるので、誘電体セラミック材料全体として元素分布が均一化でき、所望の特性が得易くなり、特性の安定したコンデンサを得ることができる。
【図面の簡単な説明】
【図１】（Ａ）、（Ｂ）はそれぞれ本発明による誘電体セラミック材料の製造方法の実施例、比較例における副成分の製造工程図、（Ｃ）は従来の副成分の製造工程図である。
【図２】本発明において用いるプラズマ法を実施する装置の概略構成図である。
【図３】本発明の製造方法により得た副成分を用いて積層セラミックコンデンサを得る製造工程図である。
【図４】本発明の実施例、比較例および従来例における高温加速寿命試験結果を示す図である。
【符号の説明】
１：プラズマトーチ、２：顆粒の導入口、３：ガス導入口、４：冷却炉、５：捕集炉[0001]
[Industrial application fields]
The present invention relates to a method for manufacturing a dielectric ceramic material for forming a dielectric green sheet of a multilayer ceramic capacitor having internal electrodes.
[0002]
[Prior art]
Conventionally, as a method of manufacturing a multilayer ceramic capacitor, a dielectric ceramic material mainly composed of BaTiO3 or the like is formed into a sheet shape, and a conductive paste serving as an internal electrode is applied to the surface, laminated and pressure-bonded, fired, and laminated. Methods for making ceramic capacitors are generally known.
[0003]
The dielectric ceramic material for a multilayer ceramic capacitor is usually added with several elements as subcomponents for the purpose of improving various properties such as reduction resistance, adjustment of temperature characteristics, and reliability to the main component. doing.
[0004]
Such subcomponents include three or more compounds of Ba, Ca, Sr, Mg, Si, Cr, Y, V, Mn, W, and Zr. Conventionally, in order to obtain this subcomponent, FIG. ) After preparing three or more of these compounds (step (a)), wet mixing and pulverizing (step (b)), particles were obtained by hot air drying (step (c)). Yes. The subcomponent thus obtained is mixed with the main component to form the sheet.
[0005]
In recent years, with the rapid downsizing and high density of information equipment and communication equipment, multilayer ceramic capacitors are also required to be ultra-compact and high-capacitance capacitors for use in a wide range of electronic circuits. Is coming.
[0006]
However, the conventional multilayer ceramic capacitor requires a dielectric interlayer thickness between internal electrodes of 10 μm to 20 μm because of the property of the dielectric ceramic material, and it is very difficult to make it small and have a high capacitance. It was. In addition, when the dielectric interlayer thickness is forcibly set to 10 μm or less, a conduction failure occurs between the internal electrodes, the yield is very poor, and a short circuit failure is likely to occur. This has hindered the commercialization of high capacitance, high reliability and low cost.
[0007]
In JP-A-5-124857, for the purpose of improving the dielectric breakdown voltage, the subcomponents are mixed and pulverized in advance, the average particle size is pulverized to 0.2 μm to 1.0 μm, and mixed and dispersed with the main component. A method has been proposed.
[0008]
[Problems to be solved by the invention]
When composing a dielectric ceramic material, when the subcomponent is mixed and pulverized and dried with hot air, the coagulation of the subcomponent particles is large and the average particle size of the subcomponent is large, so that it is completely dispersed in the main component phase. First, a segregation phase of about several μm (a phase in which a specific component element forms a different aggregate from other main parts and becomes inhomogeneous with the main part) or a different phase (a phase with a different crystal structure). In some cases). Reference material 1 (Refer to the reference material attached to the patent application. The same shall apply hereinafter.) The SEM diagram (secondary electron image) and the COMP diagram (characteristic X-ray image) of the second stage electron microscope from the bottom are the same. Correspondingly shown, the ones appearing in the shape of stripes are the internal electrodes of the capacitor, the black dots in the SEM diagram indicate the segregation layer, and the white dots indicate the cavities.
[0009]
Reference Material 2 shows the characteristic X-rays from the internal electrode and the base color-coded for each element and displayed on the computer screen in the electron microscope image. As shown in the third and fourth colors, each element is color-coded according to the concentration, Ba and Si are in minute amounts, while Ti and Zn are partially concentrated and segregation phases appear.
Thus, in the conventional dielectric ceramic material, the average particle size of the subcomponent increases due to aggregation of the subcomponent, and because there are segregation phases and heterogeneous phases, a large number of short-circuit defects occur and the yield decreases, There is a problem of rapid characteristic deterioration in the high temperature accelerated life test.
[0010]
As described in JP-A-5-124857, even when the average particle size of the subcomponent is 0.2 μm to 1.0 μm, the thickness between the internal electrodes cannot be 10 μm or less. Even if a monolithic ceramic capacitor having a thickness of about 10 μm is commercialized, there are problems such as a rapid decrease in yield due to the short-circuit failure described above and a rapid deterioration of characteristics in a high-temperature accelerated life test.
[0011]
In view of the above-mentioned problems of the prior art, the object of the present invention is to improve the dispersibility of the subcomponents and to make the composition uniform, thereby suppressing the occurrence of segregation phase and having a dielectric interlayer thickness of 10 μm or less. Another object of the present invention is to provide a method for manufacturing a dielectric ceramic material for producing a small-sized, high capacitance, low-cost, high-reliability multilayer ceramic capacitor that has no short-circuit defect and little deterioration with time.
[0012]
[Means for Solving the Problems]
In order to achieve the above object, the present invention provides:
Based on one or more of BaTiO ₃ , CaTiO ₃ , SrTiO ₃ or BaZrO ₃ as a main component,
As a subcomponent to be mixed with the main component, one containing at least three or more compounds selected from the compounds of Ba, Ca, Sr, Mg, Si, Cr, Y, V, Mn, W, and Zr is used.
Mixing and crushing the accessory ingredients to produce granules,
The sub-component granules are made into a gas stream with a plasma flame at 2000 ° C. to 20000 ° C. and then cooled to form ultrafine particles having an average particle size of 0.001 μm to 0.15 μm,
After wet pulverizing the ultrafine particles, freeze drying,
A dielectric ceramic material is produced by mixing the lyophilized subcomponent powder in an amount of 0.2 wt% to 10.0 wt% with respect to the main component.
[0013]
In the present invention, BaTiO ₃ and BaZrO ₃ as main components are high dielectric constant materials, and CaTiO ₃ and SrTiO ₃ are main components of temperature compensated low dielectric constant materials. Adding subcomponents of various blends in an amount of 0.2 wt% or more and 10.0 wt% or less based on the main component gives reduction resistance during firing of the dielectric material, adjustment of dielectric characteristics and temperature characteristics, high temperature acceleration Required to improve the reliability of the life test. In the present invention, the subcomponents are wet-pulverized and then freeze-dried to maintain the state of fine particles having a small average particle size without causing aggregation .
[0014]
By mixing and dispersing the subcomponents composed of the fine particles obtained in this way into the main component, the subcomponent is uniformly dispersed in the main component, the composition is uniform, and there is almost no occurrence of heterogeneous phase or segregation phase, or heterogeneous phase or segregation. A dielectric ceramic material for producing a multilayer ceramic capacitor in which the phase becomes smaller, the short circuit defect does not increase rapidly, and the characteristics are not deteriorated even in the high temperature accelerated life test can be obtained.
[0015]
In addition, even when the average particle size of the subcomponent is 0.001 μm, the short-circuit defect is improved, but if it is less than 0.001 μm, it becomes expensive, and moreover, it tends to aggregate during wet mixing and drying. Become. Moreover, when the average particle diameter of a subcomponent exceeds 0.15 micrometer, the increase in short circuit defect is seen and it is preferable that an average particle diameter is 0.15 micrometer or less.
[0016]
In the present invention, when three or more kinds of subcomponents are processed by the plasma method, the properties of the subcomponents are such that each particle is composed of a single component by pulverization as described in JP-A-5-124857. Instead, it can be made amorphous by mixing three or more kinds of components in the individual particles by plasma treatment, so that desired characteristics can be easily obtained and the characteristics are stabilized .
[0017]
DETAILED DESCRIPTION OF THE INVENTION
[Example 1]
FIG. 1A is a process diagram showing one embodiment of a method for producing a dielectric ceramic material of the present invention. First, the subcomponent granules are prepared by weighing BaCO ₃ , CaCO ₃ , SiO ₂ , Y ₂ O ₃ , MgCO ₃ , Cr ₂ O ₃ , V ₂ O ₅ , and ZrO ₂ (step (a)), respectively. A ball mill is used for wet mixing and pulverization using an organic solvent as a dispersion medium (step (b)), and after dehydration and hot-air drying (step (c)), granules having an average particle size of 0.5 μm to 2.0 μm are obtained.
[0018]
Next, a plasma processing apparatus having a schematic structure as shown in FIG. 2 (in the figure, 1 is a plasma torch, 2 is an inlet for granules, 3 is a gas inlet, 4 is a cooling furnace, and 5 is a collection furnace. In the plasma flame generated by introducing the granules from the inlet 2 above the apparatus and introducing argon gas and nitrogen gas into the plasma torch 1 from the gas inlet 3 and heating at a high frequency to 10000 ° C. The gas stream of the subcomponent gasified through was rapidly cooled in the cooling furnace 4 to obtain ultrafine particles having an average primary particle diameter of 0.001 μm or more and 0.20 μm or less (step ( d)). Ultrafine particles having an average particle diameter of 0.001 to 0.20 μm were obtained by changing the cooling rate of the gasified subcomponent. Secondary component granules having average particle diameters of 0.001, 0.01, 0.03, 0.05, 0.10, 0.15, and 0.20 μm were obtained in order of increasing cooling rate.
[0019]
Further, the auxiliary component was wet-mixed and pulverized with a ball mill using pure water as a dispersion medium (step (e)).
[0020]
Next, the mud proof produced in the above step e is put into a metal vat, and the mud proof is frozen at −10 ° C., and then vacuumed at 0 ° C. to sublimate the moisture, that is, freeze-dried. Granules were prepared in which the particles of the compound were not agglomerated (step (f)).
[0021]
A multilayer ceramic capacitor was produced by the process shown in FIG. 3 using the subcomponent thus produced. First, 3 wt% of the subcomponent is added to the main ingredient raw material of BaTiO ₃ having an average particle size of 0.7 μm, an organic solvent is used as a dispersion medium in a ball mill, and an organic binder and plasticizer are added. And a slurry made of a ceramic material was prepared (step (a)).
[0022]
Using the slurry, a sheet was formed by a doctor blade method to obtain a dielectric ceramic green sheet and dried (steps (b) and (c)).
[0023]
A conductive paste is printed on a plurality of internal electrode patterns on one surface of the obtained green sheet (step (d)), dried (step (e)), and then laminated with a plurality of green sheets (step (f)). ) And then cut (step (g)) to form a multilayer ceramic capacitor multilayer body.
[0024]
This laminate is heated in air at 320 ° C. for 5 hours to perform a binder removal treatment, and then fired at about 1200 ° C. for 2 hours in a reducing gas flow with a H ₂ / N ₂ volume ratio of 3/100. Thus, a sintered body was produced (step (h)).
[0025]
Next, in order to compensate for the oxygen deficient due to the firing, firing is performed at 800 ° C. for 4 hours in an air atmosphere to re-oxidize, and a Cu paste is applied to both ends of the sintered body and baked, whereby a terminal electrode is formed. The multilayer ceramic capacitor was formed (step (i)).
[0026]
The thickness of the internal electrode of the multilayer ceramic capacitor was 1.5 μm, the thickness of the dielectric layer between the internal electrodes was 5 μm, and the number of stacked dielectric layers was 210 layers. The external dimensions of the product are 3.2 mm × 1.6 mm × 1.2 mm .
[0027]
[Comparative Example 1]
On the other hand, instead of the plasma treatment in the step (d) of FIG. 1 (A) , as shown in FIG. 1 (B) (d), the powder having an average particle size of 0.5 μm to 2.0 μm is obtained. In an air atmosphere roasting furnace, it is heated at 700 ° C. and then rapidly cooled, and then this auxiliary component is wet pulverized in a ball mill using water as a dispersion medium ((e) in FIG. 1 (B)) , By making the average particle size 0.1 μm and freeze-drying as described above ((f) in FIG. 1 (B)), subcomponents having almost no aggregation were obtained. Subsequent steps produced a monolithic ceramic capacitor having the same dimensions as in Example 1.
[0028]
[Comparative Example 2]
In Comparative Example 1 , the average particle size was 1.0 μm, and in the other steps, a multilayer ceramic capacitor having the same dimensions as in Comparative Example 1 was produced.
[0029]
[Conventional example]
As a conventional example, BaCO ₃ , CaCO ₃ , SiO ₂ , Y ₂ O ₃ , MgCO ₃ , Cr ₂ O ₃ , V ₂ O ₅ are used as subcomponents by steps (a) to (c ) in FIG. ZrO ₂ was weighed and prepared, and mixed and pulverized with a ball mill using an organic solvent as a dispersion medium. The dried mud scourers were dried with hot air using a batch furnace to form granules. The produced granule was a powder having an average particle diameter of 1.5 μm to 2.0 μm. This granule was directly mixed with the main component composed of BaTiO ₃ , and the other steps were performed in the same manner as in the above example to produce a multilayer ceramic capacitor having the same dimensions.
[0030]
[Short defect rate test and high temperature accelerated life test]
The ceramic capacitors according to Example 1, Comparative Example 1, and the conventional example were evaluated by a withstand voltage failure rate (short failure rate) and a high temperature accelerated life test. With regard to the breakdown voltage failure, a DC voltage of 10 V was applied and the insulation resistance after 30 seconds was 100 MΩ or less. The high temperature accelerated life test was performed by continuously applying an ambient temperature of 200 ° C. and a DC voltage of 25V. The results are shown in Table 1. In FIG. 4, the horizontal axis indicates time, and the vertical axis indicates the occurrence rate of short-circuit defects.
[0031]
[Table 1]

[0032]
Example 1 in Table 1 is a result of testing 100 particles having an average particle size (average particle size after lyophilization) of 0.03 μm of primary particles of subcomponents. In addition, Comparative Examples 1 and 2 in Table 1 are the results of testing 100 particles of subcomponents having an average primary particle size of 0.1 μm. The conventional examples in Table 1 are the results of testing 100 samples having an average particle size of 1.0 μm.
[0033]
In addition, Example 1 in FIG. 4 is a test result for a subcomponent having an average primary particle diameter of 0.03 μm, and Comparative Example 1 in FIG. FIG. 4 shows the test results for the 1 μm particles, and the conventional example in FIG. 4 shows the test results for the subcomponent primary particles having an average particle diameter of 1.0 μm.
[0034]
As is apparent from Table 1, according to Example 1 , the short-circuit defect rate is reduced to about 1/240 or less as compared with the conventional example, and compared with Comparative Examples 1 and 2, it is reduced to 1/10. ing. Further , according to Example 1 , the life in the high temperature load test is also about 6 to 240 times longer than that of the conventional example and Comparative Examples 1 and 2 . In addition, in the case of freeze-drying after plasma treatment as in Example 1 of FIG. 4, if the average particle size is reduced, good results can be obtained in the results of the high-temperature accelerated life test and the short-circuit failure test.
[0035]
In Example 1 employing the plasma method, when the average particle size is 0.15 μm, the short-circuit defect rate is reduced to about 1/6 and the accelerated life is doubled compared to the case where the average particle size is 0.2 μm. Extended. In addition, in the range where the average particle diameter is 0.001 μm to 0.15 μm, the occurrence rate of short-circuit failure decreases as the average particle diameter decreases, and the accelerated lifetime also increases. On the other hand, when the average particle size is less than 0.001 μm, aggregation tends to occur and production becomes difficult. Therefore, the average particle size of the primary particles is preferably 0.001 μm to 0.15 μm.
[0036]
Reference Material 3 shows the dispersion state of particles in the case of the conventional method, Example 1, and Comparative Example 1 , respectively. In Reference Material 3, the plasma method shown at the right end shows the element concentration distribution after mixing the subcomponent having an average particle size of 0.03 μm as the main component in Example 1. Moreover, what is shown about the roasting method shows the concentration distribution of Ca and Si elements after the subcomponents with an average particle size of 0.1 μm obtained by the roasting method are mixed with the main component. . The conventional method (STD) is obtained by mixing the subcomponents shown in the above-mentioned conventional example into the main component. As is apparent from Reference Material 3, when the plasma method is used, each element of the subcomponent is amorphous mixed with each element, so that each element is uniformly present in the entire particle assembly. be able to. Further, in the case of the roasting method, since each particle of the subcomponent exists as a compound of each element, it is possible to obtain a state in which each element is uniformly distributed as a whole particle assembly as in the plasma method. In any case, compared with the case of the conventional method, a fine and uniform component distribution can be obtained, and short circuit defects can be reduced and characteristics can be stabilized.
[0037]
Reference Material 4 uses a subcomponent having an average primary particle size of 0.03 μm (BET value 30 m 2 / g) in Example 1 and sets the thickness of the dielectric layer between the internal electrodes to 7 μm, 4 μm, 2 μm. It is the COMP photograph by an electron microscope at the time of changing to .
[0038]
【The invention's effect】
In the present invention, one or more of BaTiO ₃ , CaTiO ₃ , SrTiO _3, or BaZrO ₃ is used as a main component, and subcomponents mixed with the main component include Ba, Ca, Sr, Mg, Si, and Cr. , Y, V, Mn, W, using a compound containing at least three compounds selected from each compound of Zr, mixing the subcomponents, pulverizing to produce granules, , By making it a gas stream with a plasma flame of 2000 ° C. to 20000 ° C. and then cooling it to make ultrafine particles having an average particle diameter of 0.001 μm to 0.15 μm, wet-pulverizing the ultrafine particles, and then freeze-drying, A manufacturing method for manufacturing a dielectric ceramic material by mixing the lyophilized subcomponent powder in an amount of 0.2 wt% to 10.0 wt% with respect to the main component. In addition to being obtained by freeze-drying, it is possible to prevent aggregation of subcomponents and maintain the state of ultrafine particles. For this reason, by improving the dispersibility with respect to the main component of the subcomponent and making the composition uniform, the occurrence of segregation phase is suppressed, and even if the dielectric interlayer thickness is 10 μm or less, there is no short-circuit defect, and due to aging. A small, high capacitance, low cost, highly reliable multilayer ceramic capacitor with little deterioration in characteristics can be produced.
[0039]
Moreover, after preparing the sub-component granules, the average particle diameter 0.001μm or more by the plasma method, since to obtain the following micronized 0.15 [mu] m, and a part or all of the sub-component amorphous Therefore, the element distribution can be made uniform in the entire dielectric ceramic material, desired characteristics can be easily obtained, and a capacitor having stable characteristics can be obtained.
[Brief description of the drawings]
FIGS. 1A and 1B are production process diagrams of subcomponents in an example of a dielectric ceramic material production method according to the present invention and comparative examples, respectively, and FIG. 1C is a production process diagram of conventional subcomponents. is there.
FIG. 2 is a schematic configuration diagram of an apparatus for performing a plasma method used in the present invention.
FIG. 3 is a production process diagram for obtaining a multilayer ceramic capacitor using subcomponents obtained by the production method of the present invention.
FIG. 4 is a diagram showing results of high-temperature accelerated life tests in examples , comparative examples, and conventional examples of the present invention.
[Explanation of symbols]
1: Plasma torch, 2: Granule inlet, 3: Gas inlet, 4: Cooling furnace, 5: Collection furnace

Claims (1)

Based on one or more of BaTiO ₃ , CaTiO ₃ , SrTiO ₃ or BaZrO ₃ as a main component,
As a subcomponent to be mixed with the main component, one containing at least three or more compounds selected from the compounds of Ba, Ca, Sr, Mg, Si, Cr, Y, V, Mn, W, and Zr is used.
Mixing and crushing the accessory ingredients to produce granules,
The sub-component granules are made into a gas stream with a plasma flame at 2000 ° C. to 20000 ° C. and then cooled to form ultrafine particles having an average particle size of 0.001 μm to 0.15 μm,
After wet pulverizing the ultrafine particles, freeze drying,
A method for producing a dielectric ceramic material, comprising producing the dielectric ceramic material by mixing the secondary component powder after lyophilization in an amount of 0.2 wt% to 10.0 wt% with respect to the main component.

Images