ELECTRONIC MULTI-LAYER CERAMIC DEVICE AND CERAMIC DIELECTRIC COMPOSITION

Abstract

A multilayer ceramic electronic device comprises a dielectric layer containing a main phase having a perovskite structure represented by the general formula ABO 3 and having a secondary phase comprising barium, chromium, and a transition metal element other than chromium, and having a molar ratio of a sum of the chromium and the transition metal element other than chromium to barium of the secondary phase of 7.0 or more, a plurality of inner electrode layers surrounding the dielectric layer and facing each other, and a plurality of outer electrodes, each of which is electrically coupled to each of the plurality of inner electrode layers.

Description

AREA

[0001] A particular aspect of the present disclosure relates to a multilayer ceramic electronic device and a ceramic dielectric composition. BACKGROUND

[0002] In high-frequency communication systems, such as mobile phones, multilayer ceramic electronic components, such as multilayer ceramic capacitors (MLCCs), are used to eliminate noise. SUMMARY OF THE INVENTION

[0003] According to one aspect of the embodiments, there is provided a multilayer ceramic electronic device comprising: a dielectric layer comprising a main phase having a perovskite structure represented by the general formula ABO 3and having a secondary phase comprising barium, chromium, and a transition metal element other than chromium, and having a molar ratio of a sum of the chromium and the transition metal element other than chromium to barium of the secondary phase of 7.0 or more, a plurality of inner electrode layers surrounding the dielectric layer and facing each other, and a plurality of outer electrodes, each of which is electrically coupled to each of the plurality of inner electrode layers.

[0004] According to another aspect of the embodiments, there is provided a ceramic dielectric composition comprising: a main phase having a perovskite structure represented by the general formula ABO 3and a secondary phase comprising barium, chromium and a transition metal element other than chromium, wherein a molar ratio of a sum of the chromium and the transition metal element other than chromium to barium of the secondary phase is 7.0 or more. BRIEF DESCRIPTION OF THE DRAWINGS Fig. 1 shows a ceramic dielectric composition according to a first embodiment; Fig. 2 shows a unit grid; Fig. 3 is a perspective view of a multilayer ceramic capacitor showing a cross section of a portion of the multilayer ceramic capacitor; Fig. 4 is a cross-sectional view taken along the line AA in the Fig. 4; Fig. 5 is a cross-sectional view taken along line BB in the Fig. 3; Fig. 6 shows a manufacturing process of a multilayer ceramic capacitor; Fig. 7A and Fig. 7B shows a forming process for an inner electrode; Fig. 8 shows a squeezing process; and Fig. 9 shows a case where a side margin portion. DETAILED DESCRIPTION

[0005] In recent years, in order to downsize multilayer ceramic capacitors and provide them with larger capacitance, the dielectric layer has been thinned and stacked more tightly. However, as the dielectric layer is thinned, structural defects caused by sintering and grain growth of the dielectric particles in the dielectric layer and the metal particles in the inner electrode layer are more likely to occur, which may lead to an increase in the short-circuit rate and a decrease in reliability due to a shortened service life.

[0006] Therefore, a technology has been disclosed that prevents the grain growth of metal particles in the inner electrode layer by forming deposited grains, which are chromium-containing oxides, in the dielectric layer (see, for example, International Publication No. 2008 / 072448).

[0007] However, there is no disclosure of the detailed composition of the chromium-containing deposited grains, and there is a risk that the reliability may be significantly degraded depending on the composition of the deposited grains.

[0008] An exemplary embodiment will be described below with reference to the accompanying drawings.

[0009] (First Embodiment) The ceramic dielectric composition according to a first embodiment is a polycrystalline ceramic body comprising crystal grains having a perovskite structure represented by the general formula ABO 3These polycrystalline ceramic bodies comprise one or more main phase crystal grains 40, as shown in the Fig. 1 is shown.

[0010] The main phase crystal grains 40 have a perovskite structure represented by the general formula ABO 3 is shown. The main phase crystal grains 40 have, for example, a core-shell structure. When the main phase crystal grains 40 have the core-shell structure, the main phase crystal grains 40 have a substantially spherical core portion 411 and a shell portion 412 surrounding and covering the core portion 411, as shown in the Fig.1. The core portion 411 is a crystal portion in which no additive compound exists as a solid solution, or in which the amount of additive compound present as a solid solution is small. The shell portion 412 is a crystal portion in which the additive compound exists as a solid solution and has a higher additive compound concentration than the additive compound concentration of the core portion 411.

[0011] Crystal grains with a perovskite structure, which are the main components of the first crystal grains 41, have a unit cell as shown in the Fig.2. This unit cell has an A position located at a vertex of the lattice, an O position located at the face center of the lattice, and a B position located within an octahedron with the O position as the vertex. In the perovskite structure, alkaline earth metals that can provide divalent cations, such as barium (Ba), strontium (Sr), or calcium (Ca), are located at the A position, and hafnium (Hf), zirconium (Zr), or titanium (Ti), which can provide tetravalent cations, are located at the B position.

[0012] The perovskite structure also allows for a composition formula that deviates from the stoichiometric composition. That is, the ratio of the element at position A to the element at position B does not necessarily have to be 1:1, and defects can be created within a range where the perovskite structure can be maintained. Furthermore, defects can also be created with respect to oxygen. For example, if the composition formula A α BO 3-β compositions in the ranges of 0.98 ≤ α ≤ 1.01 and 0 ≤ β ≤ 0.20 are permitted.

[0013] However, due to the generation of oxygen vacancies, for example, the resistivity decreases and ionic conductivity occurs, which reduces the electrical lifetime when used as a multilayer ceramic capacitor and increases the dielectric loss. Therefore, at least one of the alkaline earth elements magnesium (Mg), calcium (Ca), strontium (Sr), or barium (Ba) can be optionally added to the main phase crystal grains 40 having the perovskite structure. This can improve the resistivity and electrical resistance.

[0014] Furthermore, the main phase crystal grains 40 may optionally contain at least one of the first transition elements scandium (Sc), titanium (Ti), vanadium (V), chromium (Cr), iron (Fe), cobalt (Co), nickel (Ni), copper (Cu), or zinc (Zn). This can improve the resistivity, increase the electrical lifetime, and reduce the dielectric loss relative to the electrostatic capacity.

[0015] The main phase crystal grains 40 may also optionally contain at least one of the second transition elements yttrium (Y), zirconium (Zr), niobium (Nb), molybdenum (Mo), ruthenium (Ru), rhodium (Rh), palladium (Pd), or silver (Ag). This can improve resistivity, increase electrical durability, and reduce dielectric loss relative to electrostatic capacity.

[0016] The main phase crystal grains 40 may also optionally contain at least one of the third transition elements lanthanum (La), cerium (Ce), praseodymium (Pr), neodymium (Nd), samarium (Sm), europium (Eu), gadolinium (Gd), terbium (Tb), dysprosium (Dy), holmium (Ho), erbium (Er), thulium (Tm), ytterbium (Yb), lutetium (Lu), hafnium (Hf), tantalum (Ta), tungsten (W), rhenium (Re), osmium (Os), iridium (Ir), platinum (Pt), or gold (Au). This can improve resistivity, increase electrical durability, and reduce dielectric loss relative to electrostatic capacitance.

[0017] By using at least one of the alkaline earth element, the first transition metal element, the second transition metal element, or the third transition metal element as an additive, at least one of the alkaline earth element, the first transition metal element, the second transition metal element, and the third transition metal element can be solid-solved from the interface of the main phase crystal grains 40 to the interior in the firing temperature range of 1000°C to 1400°C to obtain a ceramic dielectric composition, thereby generating the core portion 411 and the shell portion 412 in the main phase crystal grains 40.

[0018] Furthermore, in a core-shell structure, generally, as the firing temperature increases, more of the various additives in the crystal grains made of barium titanate are solid-dissolved, and the shell portion 412 tends to become thicker and the grain size of the core portion 411 tends to become smaller. In the shell portion 412, an acceptor element with a lower valence than titanium, such as magnesium or nickel, is solid-dissolved as a B-position element, which prevents reduction of titanium during reduction firing and improves insulation resistance. Therefore, for example, to ensure high insulation resistance of the multilayer ceramic capacitor, it is necessary that the acceptor element be solid-dissolved in the shell portion 412.

[0019] However, excessive solid solution of the acceptor element in the shell portion 412 may promote the grain growth of the main phase crystal grains 40, increasing the short-circuit rate. Therefore, to ensure a high yield, it is necessary to precisely adjust the amount of the acceptor element present as a solid solution in the shell portion 412, but this precise adjustment has been difficult.

[0020] The inventors have conducted extensive research and found that the deterioration of the short circuit rate and reliability by depositing the first crystal grains 41 contained in the Fig.1 can be prevented. In particular, the inventors have found that the deterioration of the short-circuit rate and reliability can be prevented by depositing the first crystal grains 41 containing barium, chromium, and transition metal elements other than chromium, and in which the molar ratio of the sum of chromium and transition metal elements other than chromium to barium is 7.0 or more.

[0021] It is believed that the secondary phase of oxides containing chromium prevents abnormal grain growth during firing, reduces the short-circuit rate, sufficiently promotes the diffusion of oxide ions during reoxidation, and provides sufficient electrical durability. Furthermore, the presence of a transition metal with an ionic radius different from that of chromium and a transition metal with a valence different from that of chromium in addition to chromium sufficiently promotes the diffusion of oxide ions during reoxidation and provides sufficient electrical durability.

[0022] From the viewpoint of sufficiently preventing a reduction in reliability, the molar ratio of the sum of chromium and transition metal elements other than chromium to barium in the first crystal grains 41 is preferably 7.2 or more, and more preferably 7.5 or more.

[0023] On the other hand, if the molar ratio of the sum of chromium and transition metal elements other than chromium to barium in the first crystal grains 41 is too large, the electrical durability may be reduced. Therefore, it is preferable to set an upper limit on the molar ratio of the sum of chromium and transition metal elements other than chromium to barium. In this embodiment, the molar ratio of the sum of chromium and transition metal elements other than chromium to barium in the first crystal grains 41 is preferably 9.0 or less, more preferably 8.8 or less, and even more preferably 8.5 or less.

[0024] If the amount of chromium in the first crystal grains 41 is small, the diffusion of oxide ions may not be sufficiently promoted during the re-oxidation process, and a sufficient electrical life may not be obtained. Therefore, it is preferable to set a lower limit on the amount of chromium in the first crystal grains 41. In this embodiment, the molar ratio of chromium to barium in the first crystal grains 41 is preferably 2.0 or more, more preferably 2.3 or more, and even more preferably 2.6 or more.

[0025] On the other hand, if the amount of chromium in the first crystal grains 41 is large, the electrical durability may be reduced. Therefore, it is preferable to set an upper limit on the amount of chromium in the first crystal grains 41. In this embodiment, the molar ratio of chromium to barium in the first crystal grains 41 is preferably 6.0 or less, more preferably 5.5 or less, and even more preferably 5.0 or less.

[0026] The crystal system of the first crystal grains 41 is preferably orthorhombic. By making the crystal system of the first crystal grains 41 orthorhombic, excessive diffusion of the additional element into the main phase crystal grains 40 via the first crystal grains 41 during firing is prevented, and an increase in the short-circuit rate can be prevented.

[0027] The space group of the first crystal grains 41 is preferably Cmce. By setting the space group of the first crystal grains 41 to Cmce, excessive diffusion of the additional elements into the main phase crystal grains 40 via the first crystal grains 41 during firing is prevented, and an increase in the short-circuit rate can be prevented.

[0028] In the first crystal grains 41, the transition metal element other than chromium is preferably an element located near chromium in the periodic table. For example, in the first crystal grains 41, the transition metal element other than chromium is preferably at least one of titanium, vanadium, manganese, iron, or nickel. For example, two or more elements can be used in combination as the transition metal element other than chromium. For example, titanium and nickel can be used in combination as the transition metal element other than chromium.

[0029] The inclusion of the first crystal grains 41 in the ceramic dielectric composition can be confirmed by the following method.

[0030] First, the surface of the ceramic dielectric composition is exposed. There are no particular restrictions on the exposure method, and methods such as cutting or polishing the element can be employed. In this case, in order to fully examine the internal ceramic structure, it is preferable to finally obtain smoothness that can be judged as a mirror surface using a diamond paste of 2 micrometers or less or the like. The above method of cutting or polishing the element is suitable for inspection with an SEM. Further, a thin piece with a thickness of 100 nm or less of the surface of the ceramic dielectric composition with smoothness that can be judged as a mirror surface can be obtained using an ion beam or the like. The above thin piece is suitable for inspection with an STEM.

[0031] Next, the composition of the first crystal grains 41 is determined by an energy dispersive X-ray spectrometer (EDS) or a wavelength dispersive X-ray spectrometer (WDS) attached to a scanning electron microscope (SEM) or a scanning transmission electron microscope (STEM), an electron probe microanalyzer (EPMA), a laser irradiation type inductively coupled plasma mass spectrometry (LA-ICPMS), or the like.

[0032] For example, in an EDS measurement, the composition is simply determined by the intensity of the K-line of chromium relative to the K-line or L-line of barium, the K-line intensity of titanium, the K-line intensity of vanadium, the K-line intensity of manganese, the K-line intensity of iron, and the K-line intensity of nickel. Specifically, based on these intensities, a correction (ZAF correction) is applied that takes into account the atomic number effect, the absorption effect, and the fluorescence excitation effect, and the proportion of each relative to the element content of barium is calculated, which is the proportion of each element.

[0033] If the sample thickness is sufficiently small, for example, less than a few tenths of a nm, a correction can be made using the proportionality coefficient (K factor) used in the Cliff-Rolimer method to obtain the content of each element. In addition to the correction used in the Cliff-Rolimer method, a correction can be made taking into account the absorption effect of the sample to obtain the content of each element. The absorption effect of the sample can be corrected by determining the thickness and density of the sample. The thickness of the sample can be determined, for example, by obtaining a convergent beam electron diffraction (CBED) pattern under dual-wave excitation conditions and analyzing the locking curve observed on a diffraction disk.The grains used to obtain the CBED pattern may be the main phase crystal grains 40 or the like. The density of the sample may be, for example, 6.02 g / cm. 3 which is the density of barium titanate.

[0034] When performing EDS measurements, especially when using the Lα line of barium and the Kα line of titanium, their energy peaks are close to each other, and it may be difficult to adequately compare the element contents. For this reason, it is preferable that the Lβ2 line and Lβ1β line of barium be obtained with sufficient intensity without peak overlap during measurement. In particular, it is preferable that the intensity at the peak be 10,000 counts or more. This allows the intensity of the characteristic X-rays of barium to be determined and the element content to be calculated, so that even if the Lα lines of barium and the Kα lines of titanium overlap, the intensity of the Kα lines of titanium can be determined and the element content can be evaluated with high accuracy.

[0035] The crystal grains obtained by the above method, in which the molar ratio of chromium and transition metals other than chromium (one or more of titanium, vanadium, manganese, iron, or nickel) to barium is 7.0 or more, are determined to be the first crystal grains 41. In other words, when a secondary phase is detected in which the element ratio of chromium and transition metals other than chromium (one or more of titanium, vanadium, manganese, iron, or nickel) to barium is higher compared to the main phase crystal grains 40 made of barium titanate and existing in the environment, it is determined that the first crystal grains 41 are present.In this case, when an SEM is used for observation, the first crystal grains 41 are characterized by being visible with a relatively low brightness when observed using a backscattered electron image (BSE image) and appearing darker than the main phase crystal grains 40. Further, when an STEM is used for observation, the first crystal grains 41 are characterized by being visible with a relatively low brightness when observed in a steep-angle annular dark-field scanning transmission electron microscopy (HAADF-STEM image) and appearing darker than the main phase crystal grains 40.

[0036] Furthermore, when the grain diameter of the first crystal grains 41 is smaller than the spatial resolution of the EDS analysis in the SEM, it is preferable to determine the composition of the first crystal grains 41 using a scanning transmission electron microscope (STEM).

[0037] Furthermore, when confirming the crystal structure of the first crystal grains 41, it is preferable to acquire selected area electron diffraction (SAED) patterns of the first crystal grains 41 using a transmission electron microscope (TEM) and analyze the obtained electron diffraction pattern. It is also preferable to obtain electron diffraction patterns for multiple crystal zone axes and confirm that indexing with crystal structures having similar crystal systems, space groups, and lattice constants is possible.

[0038] There is no particular limitation on the method for calculating the cross-sectional area of ​​the main phase crystal grains 40 and the first crystal grains 41. However, for example, for each of the main phase crystal grains 40 and the first crystal grains 41, image processing is performed on the BSE image acquired by the SEM, and the number of pixels of the area occupied by each of the main phase crystal grains 40 and the first crystal grains 41 in the image is counted, thereby calculating the cross-sectional area of ​​each of the main phase crystal grains 40 and the first crystal grains 41. When the total cross-sectional area of ​​the main phase crystal grains 40 and the first crystal grains 41 is calculated by the above method, for example, the proportion of the first crystal grains 41 is preferably 0.050% to 45.0%, preferably 0.50% to 25.0%, and more preferably 1.0% to 15.0%.

[0039] As it is in the Fig. 1, the ceramic dielectric composition preferably contains, in addition to the main phase crystal grains 40 and the first crystal grains 41, second crystal grains or glass grains 43 that have a different composition or crystal structure from the main phase crystal grains 40 and the first crystal grains 41 and contain silicon. By including at least one of the second crystal grains 42 and the glass grains 43 in the ceramic dielectric composition, the ceramic dielectric composition can be sintered at 1300°C or less, and the ceramic dielectric composition can be sufficiently densified. Crystal grains such as silicate (SiO 2 ), enstatite (MgSiO 3 ), barium magnesium silicate (BaMgSiO 4 ) and Fresnoit (Ba 2 TiSi 2 O 8) can be used. Glass grains such as silicate (SiO 2 ), enstatite (MgSiO 3 ), barium magnesium silicate (BaMgSiO 4 ) and Fresnoit (Ba 2 TiSi 2 O 8 ) be used.

[0040] The ceramic dielectric composition may contain other compounds derived from added substances or electrodes, such as geikierite (MgTiO 3 ), manganese nickel oxide ((Mn,Ni)O) and pyrophanite (MnTiO 3 ).

[0041] As it is in the Fig. 1, the first crystal grains 41 and the second crystal grains 42 are preferably located at the grain boundaries of the main phase crystal grains 40. This is because then a reduction in the resistivity of the ceramic dielectric composition can be prevented.

[0042] The first crystal grains 41 and the second crystal grains 42 are preferably located at the grain boundary triple junctions of the main phase crystal grains 40. This is because a reduction in the resistivity of the ceramic dielectric composition can then be prevented. The grain boundary triple junctions are the boundaries between three crystal grain boundaries.

[0043] The glass grains 43 are preferably located at the grain boundaries of the main phase crystal grains 40. This is because a reduction in the relative dielectric constant of the ceramic dielectric composition can then be prevented.

[0044] The glass grains 43 are preferably located at the grain boundary triple contact points of the main phase crystal grains 40. This is because a reduction in the relative dielectric constant of the ceramic dielectric composition can then be prevented.

[0045] It is preferable that the shell portion 412 of the main phase crystal grains 40 contains a rare earth element. This is because the electrical life of the ceramic dielectric composition is then improved.

[0046] (Second Embodiment) In a second embodiment, a multilayer ceramic capacitor 100 using the ceramic dielectric composition of the first embodiment will be described.

[0047] The Fig. 3 shows a perspective view of the multilayer ceramic capacitor 100, in which a cross section of a part of the multilayer ceramic capacitor 100 is shown. The Fig. 4 is a cross-sectional view taken along the line AA in the Fig. 4. The Fig. 5 is a cross-sectional view taken along line BB in the Fig. 3. As it is in Fig. 3 to Fig.As shown in FIG. 5, the multilayer ceramic capacitor 100 includes a multilayer chip 10 having a rectangular parallelepiped shape and external electrodes 20a and 20b disposed opposite each other on two end surfaces of the multilayer chip 10, respectively. Of four surfaces other than the two end surfaces of the multilayer chip 10, two surfaces other than the upper surface and the lower surface in the stacking direction are referred to as side surfaces. Each of the external electrodes 20a and 20b extends to the upper surface and the lower surface in the stacking direction and the two side surfaces of the multilayer chip 10. However, the external electrodes 20a and 20b are spaced apart from each other.

[0048] The multilayer chip 10 has a structure in which dielectric layers 11 containing the ceramic dielectric composition and internal electrode layers 12 composed predominantly of a base metal are alternately stacked. In other words, the multilayer chip 10 includes the internal electrode layers 12 facing each other and the dielectric layers 11 interposed between the internal electrode layers 12. The edges in the direction in which each internal electrode layer 12 extends are alternately exposed at a first end surface provided with the external electrode 20a of the multilayer chip 10 and a second end surface provided with the external electrode 20b. Thus, the internal electrode layers 12 are alternately electrically connected to the external electrode 20a and the external electrode 20b.Accordingly, the multilayer ceramic capacitor 100 has a structure in which a plurality of dielectric layers 11 are stacked with the internal electrode layers 12 interposed therebetween. In the multilayer structure of the dielectric layers 11 and the internal electrode layers 12, the outermost layers in the stacking direction are the internal electrode layers 12, and cap layers 13 cover the upper surface and the lower surface of the multilayer structure. The cap layer 13 is predominantly composed of a ceramic material. For example, the main component of the cap layer 13 may be the same as the main component of the dielectric layer 11, or it may be different from the main component of the dielectric layer 11.

[0049] For example, the multilayer ceramic capacitor 100 may have a length of 0.25 mm, a width of 0.125 mm, and a height of 0.125 mm. The multilayer ceramic capacitor 100 may have a length of 0.4 mm, a width of 0.2 mm, and a height of 0.2 mm. The multilayer ceramic capacitor 100 may have a length of 0.6 mm, a width of 0.3 mm, and a height of 0.3 mm. The multilayer ceramic capacitor 100 may have a length of 1.0 mm, a width of 0.5 mm, and a height of 0.5 mm. The multilayer ceramic capacitor 100 may have a length of 3.2 mm, a width of 1.6 mm, and a height of 1.6 mm. The multilayer ceramic capacitor 100 may have a length of 4.5 mm, a width of 3.2 mm, and a height of 2.5 mm. The size of the multilayer ceramic

[0050] The inner electrode layer 12 is predominantly composed of a base metal such as nickel (Ni), copper (Cu), or tin (Sn). The inner electrode layer 12 may be composed of a noble metal such as platinum (Pt), palladium (Pd), silver (Ag), or gold (Au), or an alloy containing one or more thereof.

[0051] As it is in the Fig. As shown in FIG. 4, the portion where the inner electrode layer 12 connected to the outer electrode 20a faces the inner electrode layer 12 connected to the outer electrode 20b is a portion where capacitance is generated in the multilayer ceramic capacitor 100. Therefore, this portion is referred to as a capacitance portion 14. That is, the capacitance portion 14 is a portion where adjacent inner electrode layers 12 connected to different outer electrodes face each other.

[0052] The portion where the inner electrode layers 12 connected to the outer electrode 20a face each other without interposing an inner electrode layer 12 connected to the outer electrode 20b is referred to as an end edge portion 15. The portion where the inner electrode layers 12 connected to the outer electrode 20b face each other without interposing an inner electrode layer 12 connected to the outer electrode 20a is another end edge portion 15. That is, the end edge portion 15 is a portion where the inner electrode layers 12 connected to one of the outer electrodes face each other without interposing an inner electrode layer 12 connected to the other of the outer electrodes. The end edge portion 15 is a portion where no capacitance is generated.

[0053] As it is in the Fig. 5, in the multilayer chip 10, a portion from one of the two side surfaces of the multilayer chip 10 to lateral side edges of the internal electrode layers 12 is referred to as a side edge portion 16. That is, each of the side edge portions 16 is a portion covering the lateral side edges, extending to one of the side surfaces of the multilayer structure, of the stacked internal electrode layers 12. The side edge portion 16 is a portion where no capacitance is generated.

[0054] In the multilayer ceramic capacitor 100 according to this embodiment, at least a portion of the dielectric layer 11 in the capacitance portion 14 includes the main phase crystal grains 40 and the first crystal grains 41 arranged in the Fig. 1. This allows high reliability and high insulation resistance to be achieved.

[0055] The thickness of the dielectric layer 11 in the stacking direction is, for example, 0.50 µm or less, 0.40 µm or less, or 0.30 µm or less. The thickness of the dielectric layer 11 can be measured by examining the cross section of the multilayer ceramic capacitor 100 with an SEM (Scanning Electron Microscope), measuring the thickness at 10 points for each of 10 different dielectric layers 11, and deriving the average value of all measurement points.

[0056] The average thickness per layer of the inner electrode layer 12 in the stacking direction is, for example, 0.50 µm or less, 0.40 µm or less, or 0.30 µm or less. The thickness of the inner electrode layer 12 can be measured by examining the cross section of the multilayer ceramic capacitor 100 with an SEM (Scanning Electron Microscope), measuring the thickness at 10 points for each of 10 different inner electrode layers, and deriving the average value of all measurement points.

[0057] Next, a manufacturing method of the multilayer ceramic capacitors 100 will be described. Fig. 6 shows a manufacturing process of the multilayer ceramic capacitor 100.

[0058] (Method for producing a raw material powder) The ceramic dielectric composition for forming the dielectric layer 11 is prepared. Generally, an A-position element and a B-position element are incorporated into the dielectric layer 11 in a sintered phase of grains of ABO 3 For example, barium titanate is a tetragonal compound with a perovskite structure and has a high dielectric constant. Generally, barium titanate is produced by reacting a titanium material such as titanium dioxide with a barium material such as barium carbonate and synthesizing barium titanate. Various methods can be used as the synthesis method of the ceramic that patterns the dielectric layer 11. For example, a solid-phase method, a sol-gel method, a hydrothermal method, or the like can be used. The embodiments may use any of these methods.

[0059] An additive compound may be suitably added to the resulting barium titanate powder. As an example, the additive of the ceramic dielectric composition of the first embodiment is used. Optionally, an oxide or a glass containing Zr (zirconium), V (vanadium), Cr (chromium), Co (cobalt), Ni (nickel), Li (lithium), B (boron), Na (sodium), K (potassium) may also be used. Optionally, an oxide of a rare earth element such as Sc (scandium), Y (yttrium), La (lanthanum), Ce (cerium), Pr (praseodymium), Nd (neodymium), Pm (promethium), Sm (samarium), Tb (terbium), Dy (dysprosium), Ho (holmium), Er (erbium), Tm (thulium), Y (ytterbium), and Lu (lutetium) may be added.

[0060] To produce the first crystal grains 41, for example, a barium titanate powder with an average particle size of 100 nm is prepared and a predetermined amount of BaCr 10 O 15 , Ho 2 O 3, NiO, TiO 2 , MgO and SiO 2 100 moles of barium titanate powder is added. The BaCr 10 O 15 -Powder is prepared by producing a barium carbonate (BaCO 3 ) powder and a chromium oxide (Cr 2 O 3 ) powder, wet mixing of 5 mol of chromium oxide powder with 1 mol of barium carbonate powder, drying the mixed powder and firing the mixed powder at 1100 to 1300 °C for 1 to 3 hours in a reducing atmosphere with an oxygen partial pressure of 10 -13 up to 10 -9 atm. For example, the ceramic material obtained in the manner described above may be optionally pulverized to adjust the particle size, or the particle size may be adjusted by combining it with a classification process. The above process results in a BaCr 10 O 15 -Powder.

[0061] For example, a compound containing an additive compound is wet-mixed with barium titanate powder, and then dried and pulverized to produce a ceramic material in which the barium titanate powder and the additive compound are mixed. For example, the ceramic material obtained in the above-described manner may be optionally pulverized to adjust the particle size, or may be combined with a classification process to adjust the particle size. The ceramic dielectric composition is obtained by the above method.

[0062] (Forming a Dielectric Green Sheet) Next, a binder such as a polyvinyl butyral (PVB) resin, an organic solvent such as ethanol or toluene, and a plasticizer are added to the resulting dielectric material and wet-mixed. Using the resulting slurry, a ceramic green sheet 51 is formed on a base material by, for example, a die coating method or a doctor blade method, and then dried. The base material is, for example, a PET (polyethylene terephthalate) film. Figures related to the formation of the dielectric green sheet are omitted.

[0063] (Forming the inner electrode structure) Next, as shown in the Fig.As shown in Figure 7A, a conductive metal paste containing an organic binder is printed on the surface of the ceramic green sheet 51 by screen printing, gravure printing, or the like to form internal electrodes. Internal electrode patterns 52 are alternately arranged on a pair of external electrodes. Ceramic particles are added to the conductive metal paste as a supplementary material. Although the main component of the ceramic particles is not specifically limited, it is preferably the same as the main component ceramic of the dielectric layer 11. For example, barium titanate having an average particle size of 50 nm or less can be uniformly dispersed.

[0064] Next, a binder such as ethylcellulose and an organic solvent such as terpineol are added to the ceramic dielectric composition obtained in the process for preparing the raw material powder, and the mixture is kneaded in a roll mill to form a dielectric pattern paste for the reverse pattern layer. As described in the Fig. As shown in Figure 7A, a dielectric pattern 53 is disposed on the ceramic green sheet 51 by printing a dielectric pattern paste in the peripheral region where the internal electrode pattern 52 is not printed, and a gap is filled with the internal electrode pattern 52. The ceramic green sheet 51 on which the internal electrode pattern 52 and the dielectric pattern 53 are printed is referred to as a stacked unit.

[0065] Afterwards, as stated in the Fig.7B, the inner electrode layers 12 and the dielectric layers 11 are alternately arranged, and the inner electrode layers 12 have edges on both end surfaces in the longitudinal direction of the dielectric layers 11. The stacking units are stacked so as to be alternately exposed and alternately led out to a pair of outer electrodes 20a and 20b having different polarities. For example, the number of stacked layers of the inner electrode structure 52 is set to 100 to 1000 layers.

[0066] (Crushing process) As it is in the Fig.As shown in Figure 8, a predetermined number (for example, 2 to 10 layers) of cover layers 54 are stacked on the top and bottom surfaces of the multilayer body in which the stacked units are stacked, and bonded by thermocompression. As an example of the ceramic material for the cover layer 54, the above-described ceramic dielectric composition can be used. Thereafter, the multilayer body is cut into a predetermined chip size (for example, 1.0 mm × 0.5 mm).

[0067] (Firing process) After removing the binder from the resulting multilayer ceramic body in a N 2 atmosphere, an air atmosphere or the like, a metal paste, which becomes the base layer of the external electrodes 20a and 20b, is applied by a dipping method and the multilayer ceramic body is heated in a reducing atmosphere at an oxygen partial pressure of 10 -12 up to 10 -9atm, 1100°C to 1300°C for 10 minutes to 2 hours. In this way, the multilayer ceramic capacitor 100 is obtained. It should be noted that the temperature is rapidly increased in the firing step. The temperature rise rate in the firing step is, for example, 6000°C / hour. This can substantially shorten the time required for firing and achieve higher mass productivity. Consequently, the main phase crystal grain 40 and the first crystal grain 41 can be generated in at least a portion of the dielectric layer 11 in the capacitance portion 14.

[0068] (Annealing process) Thereafter, the multilayer ceramic capacitor 100 is subjected to an annealing process in a reducing atmosphere at an oxygen partial pressure of 10 -12 up to 10 -9At 900°C to 1150°C, the material is gradually cooled for 30 minutes to 2 hours. The cooling rate is, for example, 200°C / hour.

[0069] (Re-oxidation treatment process) After that, a re-oxidation treatment can be carried out at 600 °C to 1000 °C in an N 2 -gas atmosphere.

[0070] (Plating Process) Next, a metal coating such as Cu, Ni, Sn, etc., is applied to the base layer of the external electrodes 20a and 20b by plating. Through the above steps, the multilayer ceramic capacitor 100 is completed.

[0071] The side edge portion may be attached to or applied to the side surface of the multilayer ceramic body. In particular, as described in Fig.9, the multilayer ceramic body is obtained by alternately stacking the ceramic green sheets 51 and the internal electrode patterns 52 having the same width as the ceramic green sheets 51. Next, a layer formed of the dielectric pattern paste may be attached as a side edge portion 55 to the side surface of the multilayer ceramic body.

[0072] The manufacturing method according to this embodiment enables the formation of the main phase crystal grain 40 which is in the Fig. 1, in at least a portion of the dielectric layer 11 in the capacitance portion 14, and also the formation of the first crystal grain 41. Thereby, the rate of short circuits can be reduced and a reduction in reliability can be prevented.

[0073] It should be noted that in the above embodiments, a multilayer ceramic capacitor has been described as an example of a multilayer ceramic electronic component, but this is not limitative. For example, other multilayer ceramic electronic components, such as varistors and thermistors, may also be used. [Examples]

[0074] (Example 1) A barium titanate powder with an average particle size of 100 nm was prepared and 0.8 mol Ho 2 O 3 , 0.2 mol BaCr 10 O 15 , 0.5 mol NiO, 0.5 mol TiO 2 , 0.5 mol MgO and 1.0 mol SiO 2 100 moles of barium titanate powder were added.

[0075] The ceramic dielectric composition was mixed with ethanol, toluene, and a PVB (polyvinyl butyral) resin to prepare a dielectric slurry. This slurry was formed into a ceramic green sheet using a die coater and dried. A conductive metal paste containing the main component metal of the inner electrode layer 12, a supplementary material, a binder (ethyl cellulose), a solvent, and optionally other auxiliaries was prepared using a planetary ball mill and applied to a ceramic green sheet by screen printing. Eleven stacking units with a conductive metal paste printed on the ceramic green sheets were stacked, and cover sheets were stacked on the top and bottom of the stacking units. Then, the multilayer structure was obtained by thermocompression bonding and cut into a predetermined shape. After the obtained multilayer structure was formed in a N 2After the binder was removed from the multilayer structure in a reducing atmosphere, a conductive metal paste containing a metal filler composed predominantly of nickel, a supplementary material, a binder, a solvent, etc., for the base layer was applied to both end faces and each side of the multilayer structure and dried. Then, the conductive metal paste for the base layer was fired at 1300 °C in a reducing atmosphere simultaneously with the multilayer structure to obtain a sintered body. The temperature rise rate was 6000 °C / hour. The shaped dimensions of the obtained sintered body were 0.6 mm in length, 0.3 mm in width, and 0.3 mm in height. Then, an annealing treatment was carried out at 900 to 1150 °C for 1 hour. Then, a re-oxidation treatment was carried out at 950 °C.Then, plating treatment was performed to form a Cu-plated layer, a Ni-plated layer, and an Sn-plated layer on the surface of the base layer, and the multilayer ceramic capacitor 100 was obtained. The average thickness of the dielectric layer 11 was 0.5 μm.

[0076] (Example 2) In Example 2, 0.8 mol of Ho 2 O 3 , 0.2 mol BaCr 10 O 15 , 0.5 mol Fe 2 O 3 , 0.15 mol V 2 O 5 , 0.5 mol MgO and 1.0 mol SiO 2 100 mol of barium titanate powder were added. The other conditions were identical to those in Example 1.

[0077] (Example 3) In Example 3, 0.8 mol of Ho 2 O 3 , 0.2 mol BaCr 10 O 15 , 0.5 mol TiO 2 , 0.25 mol Fe 2 O 3 , 0.5 mol MgO and 1.0 mol SiO 2100 mol of barium titanate powder were added. The other conditions were identical to those in Example 1.

[0078] (Example 4) In Example 4, 0.8 mol of Ho 2 O 3 , 0.2 mol BaCr 10 O 15 , 0.5 mol NiO, 0.5 mol TiO 2 , 0.5 mol MgO and 1.0 mol SiO 2 100 mol of barium titanate powder were added. The other conditions were identical to those in Example 1.

[0079] (Example 5) In Example 5, 0.8 mol of Ho 2 O 3 , 0.2 mol BaCr 10 O 15 , 0.5 mol NiO, 0.5 mol MgO and 1.0 mol SiO 2 100 mol of barium titanate powder were added. The other conditions were identical to those in Example 1.

[0080] (Example 6) In Example 6, 0.8 mol of Ho 2 O 3 , 0.15 mol BaCr 10 O 15 , 0.5 mol NiO, 0.5 mol TiO 2 , 0.5 mol MgO and 1.0 mol SiO 2100 mol of barium titanate powder were added. The other conditions were identical to those in Example 1.

[0081] (Example 7) In Example 7, 0.8 mol of Ho 2 O 3 , 0.1 mol BaCr 10 O 15 , 0.5 mol NiO, 0.5 mol TiO 2 , 0.5 mol MgO and 1.0 mol SiO 2 100 mol of barium titanate powder were added. The other conditions were identical to those in Example 1.

[0082] (Example 8) In Example 8, 0.8 mol of Ho 2 O 3 , 0.2 mol BaCr 2 O 3 , 0.5 mol NiO, 0.5 mol TiO 2 , 0.5 mol MnCO 3 , 0.5 mol MgO and 1.0 mol SiO 2 100 mol of barium titanate powder were added. The other conditions were identical to those in Example 1.

[0083] (Example 9) In Example 9, 0.8 mol of Ho 2 O 3 , 0.2 mol BaCr 10 O 15 , 0.5 mol NiO, 0.25 mol Fe 2 O 3 , 0.15 mol V2 O 5 , 0.5 mol MgO and 1.0 mol SiO 2 100 mol of barium titanate powder were added. The other conditions were identical to those in Example 1.

[0084] (Example 10) In Example 10, 0.8 mol of Ho 2 O 3 , 0.2 mol BaCr 10 O 15 , 0.5 mol TiO 2 , 0.25 mol Fe 2 O 3 , 0.5 mol MgO and 1.0 mol SiO 2 100 mol of barium titanate powder were added. The other conditions were identical to those in Example 1.

[0085] (Example 11) In Example 11, 0.8 mol of Ho 2 O 3 , 0.2 mol BaCr 10 O 15 , 0.5 mol NiO, 0.5 mol MnCO 3 , 0.15 mol V 2 O 5 , 0.5 mol MgO and 1.0 mol SiO 2 100 mol of barium titanate powder were added. The other conditions were identical to those in Example 1.

[0086] (Example 12) In Example 12, 0.8 mol of Ho 2 O3 , 0.1 mol BaCr 10 O 15 , 1.5 mol NiO, 0.5 mol TiO 2 , 0.5 mol MgO and 1.0 mol SiO 2 100 mol of barium titanate powder were added. The other conditions were identical to those in Example 1.

[0087] (Example 13) In Example 13, 0.8 mol of Ho 2 O 3 , 0.1 mol BaCr 10 O 15 , 1.0 mol NiO, 0.5 mol TiO 2 , 0.5 mol MgO and 1.0 mol SiO 2 100 mol of barium titanate powder were added. The other conditions were identical to those in Example 1.

[0088] (Example 14) In Example 14, 0.8 mol of Ho 2 O 3 , 0.1 mol BaCr 10 O 15 , 1.0 mol NiO, 0.5 mol MnCO 3 , 0.5 mol MgO and 1.0 mol SiO 2 100 mol of barium titanate powder were added. The other conditions were identical to those in Example 1.

[0089] (Example 15) In Example 15, 0.8 mol of Ho 2 O3 , 0.1 mol BaCr 10 O 15 , 1.0 mol NiO, 0.25 mol Fe 2 O 3 , 0.5 mol MgO and 1.0 mol SiO 2 100 mol of barium titanate powder were added. The other conditions were identical to those in Example 1.

[0090] (Example 16) In Example 16, 0.8 mol of Ho 2 O 3 , 0.2 mol BaCr 10 O 15 , 0.5 mol MnCO 3 , 0.15 mol V 2 O 5 , 0.5 mol MgO and 1.0 mol SiO 2 100 mol of barium titanate powder were added. The other conditions were identical to those in Example 1.

[0091] (Comparative Example 1) In Comparative Example 1, 0.8 mol of Ho 2 O 3 , 0.5 mol Cr 2 O 3 , 0.5 mol Fe 2 O 3 , 0.5 mol V 2 O 5 , 0.5 mol MgO and 1.0 mol SiO 2100 mol of barium titanate powder were added. The other conditions were identical to those in Example 1.

[0092] (Comparative Example 2) In Comparative Example 2, 0.8 mol of Ho 2 O 3 , 0.5 mol MgO, 0.5 mol MnCO 3 , 0.15 mol V 2 O 5 and 1.0 mol SiO 2 100 mol of barium titanate powder were added. The other conditions were identical to those in Example 1.

[0093] For Examples 1 to 16 and Comparative Examples 1 and 2, it was confirmed whether precipitated grains were generated in addition to the barium titanate grains of the main phase. As a result, it was confirmed that precipitated grains were generated in addition to the barium titanate grains of the main phase in all Examples 1 to 16 and Comparative Examples 1 and 2.

[0094] Next, it was confirmed whether the deposited grains were a Ba-MO phase. M refers to one or more of chromium, nickel, titanium, iron, or manganese. As a result, in Examples 1 to 16 and Comparative Example 1, it was confirmed that the deposited grains were a Ba-MO phase.

[0095] Next, the M / Ba molar ratio in the confirmed Ba-MO phase was measured. As a result, the M / Ba ratio was 7.9 in Example 1, 7.1 in Example 2, 8.4 in Example 3, 7.6 in Example 4, 7.8 in Example 5, 8.2 in Example 6, 8.6 in Example 7, 8.9 in Example 8, 9.4 in Example 9, 8.8 in Example 10, 8.8 in Example 11, 8.6 in Example 12, 7.7 in Example 13, 7.2 in Example 14, 7.3 in Example 15, 7.9 in Example 16, and 6.5 in Comparative Example 1.

[0096] Next, the Cr / Ba molar ratio in the confirmed Ba-MO phase was measured. As a result, the Cr / Ba ratio was 3.5 in Example 1, 2.2 in Example 2, 2.1 in Example 3, 3.6 in Example 4, 4.8 in Example 5, 3.2 in Example 6, 2.9 in Example 7, 2.3 in Example 8, 2.7 in Example 9, 3.9 in Example 10, 4.6 in Example 11, 2.4 in Example 12, 2.6 in Example 13, 2.8 in Example 14, 3.6 in Example 15, 2.2 in Example 16, and 2.2 in Comparative Example 1.

[0097] Next, the element M was identified in the confirmed Ba-MO phase. The elements of M were chromium, nickel, and titanium in Example 1, chromium, iron, and vanadium in Example 2, chromium, titanium, and iron in Example 3, chromium, titanium, and titanium in Example 4, chromium and nickel in Example 5, chromium, nickel, and titanium in Example 6, chromium, nickel, and titanium in Example 7, chromium, nickel, titanium, and manganese in Example 8, chromium, nickel, iron, and vanadium in Example 9, chromium, titanium, and iron in Example 10, chromium, nickel, manganese, and vanadium in Example 11, chromium, nickel, and titanium in Example 12, chromium, nickel, and titanium in Example 13, chromium, nickel, and manganese in Example 14, chromium, nickel, and iron in Example 15, chromium, manganese, and vanadium in Example 16, and chromium, iron, and vanadium in Comparative Example 1.

[0098] Next, the crystal system of the confirmed Ba-MO phase was investigated. The crystal system of the Ba-MO phase was orthorhombic in Examples 1 to 16 and monoclinic in Comparative Example 1.

[0099] Next, the space group of the confirmed Ba-MO phase was investigated. The space group of the Ba-MO phase was Cmce in Examples 1 to 16 and C2 / m in Comparative Example 1.

[0100] (Measurement of Short Circuit Rate) Next, the short circuit rate of Examples 1 to 16 and Comparative Examples 1 and 2 was measured. Using an LCR meter, the short circuit rate was evaluated under the condition that the oscillation level (OSC) was 0.5 V and a voltage with a frequency of 1 kHz was applied. For each of Examples 1 to 16 and Comparative Examples 1 and 2, 200 samples were evaluated, and the percentage of the number of samples among the 200 samples that had a short circuit was used as the short circuit rate (%).

[0101] (Reliability test) Next, the electrical life was measured for Examples 1 to 16 and Comparative Examples 1 and 2. For the cross sections of lines AA and BB shown in Fig. 4 and Fig.5, the capacitance portion 14 was exposed by cutting or polishing, and finally, the thickness t of each of the dielectric layers 11 was calculated in a state where the smoothness that can be judged as a mirror surface was obtained to be 2 micrometers or less using a diamond paste or the like. The reliability test was performed by continuously applying a DC voltage in an environment of 150°C so that the electric field strength V / t applied to the dielectric layer was 30 V / µm, and measuring the change in the DC current value flowing through the multilayer ceramic capacitor with time. The electrical life of the multilayer ceramic capacitor was defined as the time from the application of the DC voltage until the resistance value of the multilayer ceramic capacitor deteriorated and dropped below 100 Ω.

[0102] When the short-circuit rate was 25% or less and the average electrical life was greater than 3000 min, the overall evaluation was judged as very good "double circuit". When the average electrical life was greater than 1000 min, the overall evaluation was judged as good "◯". Otherwise, the overall evaluation was judged as unacceptable "×". The results are shown in Table 1. The overall evaluation of all examples 1 to 16 was very good "double circuit" or good "◯", while the overall evaluation of both comparative examples 1 and 2 was unacceptable "×". [Table 1] Separation grain Ba-MO phase Short circuit rate (%) Lifespan (min) assessment Available / not available M / Ba molar ratio Cr / Ba molar ratio M Crystal system Space group Example 1 Is available Is available 7,9 3,5 Cr, Ni, Ti Orthorhombic Cmce 10 5100 ⊙ Example 2 Is available Is available 7,1 2,2 Cr, Fe, V Orthorhombic Cmce 25 1400 ◯ Example 3 Is available Is available 8,4 2,1 Cr, Ti, Fe Orthorhombic Cmce 25 2400 ◯ Example 4 Is available Is available 7,6 3,6 Cr, Ni, Ti Orthorhombic Cmce 5 3500 ⊙ Example 5 Is available Is available 7,8 4,8 Cr, Ni Orthorhombic Cmce 5 1700 ◯ Example 6 Is available Is available 8,2 3,2 Cr, Ni, Ti Orthorhombic Cmce 15 5600 ⊙ Example 7 Is available Is available 8,6 2,9 Cr, Ni, Ti Orthorhombic Cmce 15 4200 ⊙ Example 8 Is available Is available 8,9 2,3 Cr, Ni, Ti, Mn Orthorhombic Cmce 15 2800 ◯ Example 9 Is available Is available 9,4 2,7 Cr, Ni, Fe, V Orthorhombic Cmce 10 1200 ◯ Example 10 Is available Is available 8,8 3,9 Cr, Ti, Fe Orthorhombic Cmce 0 2200 ◯ Example 11 Is available Is available 8,8 4,6 Cr, Ni, Mn, V Orthorhombic Cmce 0 1500 ◯ Example 12 Is available Is available 8,6 2,4 Cr, Ni, Ti Orthorhombic Cmce 20 3000 ⊙ Example 13 Is available Is available 7,7 2,6 Cr, Ni, Ti Orthorhombic Cmce 25 4700 ⊙ Example 14 Is available Is available 7,2 2,8 Cr, Ni, Mn Orthorhombic Cmce 10 2500 ◯ Example 15 Is available Is available 7,3 3,6 Cr, Ni, Fe Orthorhombic Cmce 10 2000 ◯ Example 16 Is available Is available 7,9 2,2 Cr, Mn, V Orthorhombic Cmce 20 2100 ◯ Comparison example 1 Is available Is available 6,5 2,2 Cr, Fe, V Monoclinic C2 / m 25 150 × Comparison example 2 Is available Not available 100 ×

[0103] In Comparative Example 2, the short-circuit rate was 100%, and a defect-free product could not be obtained, so the reliability test could not be performed. This is believed to be because the Ba-MO phase was not generated in Comparative Example 2 and abnormal grain growth was not prevented. In contrast, in Examples 1 to 16 and Comparative Example 1, the short-circuit rate was reduced to 25% or less. This is believed to be because the Ba-MO phase was generated and abnormal grain growth was prevented.

[0104] In all Examples 1 to 16, the average electrical lifetime exceeded 1000 min. This is assumed to be because the M / Ba molar ratio in the Ba-MO phase was 7.0 or more. In Comparative Example 1, the average electrical lifetime fell below 1000 min. This is assumed to be because the M / Ba molar ratio was less than 7.0.

[0105] Although the embodiments of the present invention have been described in detail, it should be noted that various changes, substitutions and alterations can be made therein without departing from the spirit and scope of the invention. QUOTES CONTAINED IN THE DESCRIPTION

[0000] This list of documents submitted by the applicant was generated automatically and is included solely for the convenience of the reader. This list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions. Cited patent literature

[0000] WO 2008 / 072448

[0006]

Claims

[1] Electronic multilayer ceramic device comprising: a dielectric layer (11) comprising a main phase (40) with a perovskite structure represented by the general formula ABO 3 and having a secondary phase (41) comprising barium, chromium and a transition metal element other than chromium and having a molar ratio of a sum of the chromium and the transition metal element other than chromium to barium of the secondary phase of 7.0 or more; a plurality of inner electrode layers (12) surrounding the dielectric layer and facing each other; and a plurality of outer electrodes (20a, 20b), each of which is electrically coupled to each of the plurality of inner electrode layers. [2] The multilayer ceramic electronic device according to claim 1, wherein the molar ratio of the chromium to the barium in the secondary phase (41) is 2.0 or more. [3] The multilayer ceramic electronic device according to claim 1 or 2, wherein a crystal system of the secondary phase (41) is orthorhombic. [4] The multilayer ceramic electronic device according to any one of claims 1 to 3, wherein a space group of the secondary phase (41) is Cmce. [5] The ceramic electronic device according to any one of claims 1 to 4, wherein the transition metal element other than chromium is at least one of titanium, vanadium, manganese, iron, or nickel. [6] The multilayer ceramic electronic device according to any one of claims 1 to 5, wherein the transition metal element other than chromium is titanium and nickel. [7] The multilayer ceramic electronic device according to any one of claims 1 to 6, wherein the main phase comprises at least barium or calcium in an A position and at least one of titanium or zirconium in a B position. [8] Ceramic dielectric composition comprising: a main phase (40) with a perovskite structure represented by the general formula ABO 3 is shown; and a secondary phase (41) comprising barium, chromium and a transition metal element other than chromium, wherein a molar ratio of a sum of the chromium and the transition metal element other than chromium to barium of the secondary phase is 7.0 or more. [9] The ceramic dielectric composition according to claim 8, wherein the molar ratio of chromium to barium in the secondary phase (41) is 2.0 or more.

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