JPWO2016006498A1 - Solid electrolyte, multilayer electronic component, and method of manufacturing multilayer electronic component - Google Patents

Abstract

The solid electrolyte is represented by the general formula {100 (La2 / 3-xLi3x) mTiO3 + aMn} (where 0.01 ≦ x ≦ 0.167, 0.99 ≦ m ≦ 1.10, 0.1 ≦ a ≦ 5). Is done. In the multilayer electronic component, the solid electrolyte layer 3 and the internal electrode layer 4 are alternately laminated, and the internal electrode layer 3 is formed of a conductive material whose main component is a base metal material such as Ni. 4 is formed of the solid electrolyte. The internal electrode material to be the internal electrode layer 3 and the solid electrolyte material to be the solid electrolyte layer 4 are fired in a reducing atmosphere so that the base metal material such as Ni is not oxidized. As a result, a solid electrolyte having a desired large capacitance and having good insulation, a multilayer electronic component using the solid electrolyte, and a method for manufacturing the multilayer electronic component are realized.

Description

  The present invention relates to a solid electrolyte, a multilayer electronic component, and a method for manufacturing the multilayer electronic component, and more specifically, a solid electrolyte mainly composed of a composite oxide having a perovskite crystal structure containing Li, La, and Ti, and The present invention relates to a multilayer electronic component such as a multilayer solid ion capacitor using the solid electrolyte, and a method for manufacturing the multilayer electronic component.

  In recent years, research and development have been conducted on solid ion capacitors that use a solid electrolyte in which ions move in a solid state to store electricity.

  For example, Patent Document 1 proposes a solid ion capacitor including a solid electrolyte having a thickness of 200 μm or less.

  In Patent Document 1, by setting the thickness of the solid electrolyte to 200 μm or less, an electric field is applied to the entire solid electrolyte, and the charge in the vicinity of one electrode can move to the vicinity of the other electrode. And the charge accumulated in each electrode can be increased, thereby increasing the capacitance significantly.

  Patent Document 1 also discloses a solid-state ion capacitor having a laminated structure, and it is considered possible to realize a solid-state ion capacitor having a small size and a large capacitance. That is, since a large capacitance can be obtained as described above by thinning the solid electrolyte, a multilayer ceramic capacitor using a conventional dielectric material is obtained by forming a multilayer structure similar to the multilayer ceramic capacitor. Compared to the above, it is considered possible to realize a solid ion capacitor having a much larger capacitance.

International Publication 2013/111804 (Claim 1, Paragraph Numbers [0032], [0072] to [0074], FIG. 4, etc.)

  By the way, when it is going to construct | assemble the solid-state capacitor of a laminated structure, base metal materials, such as Ni, are normally used for internal electrode material. Therefore, it is necessary to fire the solid electrolyte material and the internal electrode material simultaneously in a reducing atmosphere in which the base metal material is not oxidized.

  However, according to the inventor's research results, when a conventional known solid electrolyte material is used, firing in a reducing atmosphere in which a base metal material such as Ni does not oxidize, the solid electrolyte material expresses electronic conductivity, It was found that the insulation was degraded. In other words, it is difficult to obtain a solid-state solid-state capacitor having desired electrical characteristics because it causes a decrease in insulation even when co-firing with an internal electrode material in a reducing atmosphere using a conventional solid electrolyte material. It is in the situation.

  The present invention has been made in view of such circumstances, a solid electrolyte capable of securing a desired large capacitance and having good insulation, a multilayer electronic component using the solid electrolyte, and the It is an object of the present invention to provide a method for manufacturing a multilayer electronic component.

(La, Li) TiO ₃ composite oxide is widely known as an oxide-based solid electrolyte having a perovskite crystal structure (general formula A _m BO ₃ ).

The present inventor has conducted extensive research using such (La, Li) TiO ₃ composite oxide, and found that the molar ratio of (La, Li) constituting the A site to Ti constituting the B site. After adjusting the compounding ratio of Li and La in the m and A sites, the inclusion of a predetermined amount of Mn can suppress the expression of electron conductivity even when fired in a reducing atmosphere. It was found that a solid electrolyte having a good insulating property while maintaining a large capacitance can be obtained.

The present invention has been made based on such knowledge, and the solid electrolyte according to the present invention has a main component of the general formula (La _{2 / 3-x} Li _3x ) _m TiO ₃ (provided that 0.99 ≦ m ≦ 1.10, 0.01 ≦ x ≦ 0.167) and a composite oxide represented by

  Mn is contained in the range of 0.1 to 5 mole parts with respect to 100 mole parts of Ti.

  Furthermore, in the solid electrolyte of the present invention, the Mn is preferably contained in a range of 0.1 to 1 mol part with respect to 100 mol parts of Ti.

  As a result, it is possible to obtain a much larger capacitance than a multilayer ceramic capacitor using a conventional dielectric material while ensuring good insulation.

  The solid electrolyte of the present invention is preferably fired in a reducing atmosphere.

  That is, it is considered that Mn replaces Ti by firing in a reducing atmosphere, and oxygen vacancies are formed. Since these oxygen vacancies suppress the release of oxygen in the crystal lattice, even if co-firing with the base metal material, the oxidation of the base metal material is suppressed and the generation of electron conductivity is effectively suppressed. be able to. As a result, the specific resistance can be increased and even better insulating properties can be obtained as compared with the case of firing in an air atmosphere.

  In the multilayer electronic component according to the present invention, a solid electrolyte layer and an internal electrode layer are alternately stacked, and the internal electrode layer is formed of a conductive material whose main component is a base metal material, The electrolyte layer is formed of any one of the solid electrolytes described above, and the internal electrode layer and the solid electrolyte layer are fired in a reducing atmosphere in which the base metal material is not oxidized.

  In the multilayer electronic component of the present invention, the base metal material preferably contains Ni as a main component.

  As a result, it is possible to obtain a multilayer ceramic electronic component having a large capacitance, good insulation, and desired electrical characteristics.

The method for manufacturing a multilayer electronic component according to the present invention includes a synthesis step of synthesizing a solid electrolyte material using a raw material containing at least a Li compound, a La compound, a Ti compound, and a Mn compound as a starting material, and the solid electrolyte material comprising: A green sheet manufacturing step for forming a green sheet by forming into a sheet shape, a conductive film forming step for forming a conductive film mainly composed of a base metal material on the surface of the green sheet, and a green sheet on which the conductive film is formed And a laminated body forming step for forming a laminated body, and the laminated body is fired to contain a composite oxide whose main component is represented by the general formula (La _{2 / 3-x} Li _3x ) _m TiO ₃ A firing step of producing a laminated sintered body in which a solid electrolyte layer and an internal electrode layer mainly composed of the base metal material are alternately laminated, and the synthesis step includes the solid electrolyte layer, In the general formula, m is 0.99 to 1.10, x is 0.01 to 0.167, and Mn is 0.1 to 5 parts by mole with respect to 100 parts by mole of Ti. The method includes a step of weighing each of the Li compound, the La compound, the Ti compound, and the Mn compound, and the firing step is characterized by firing in a reducing atmosphere in which the base metal material is not oxidized.

  In the method for manufacturing a multilayer ceramic electronic component of the present invention, it is preferable that the base metal material contains Ni as a main component.

  Further, in the method for producing a multilayer ceramic electronic component of the present invention, the synthesis step includes a main component powder preparation step in which the Li compound, La compound, and Ti compound are weighed and calcined to prepare a main component powder. It is also preferable to include a slurry preparation step of weighing the Mn compound, adding the Mn compound to the main component powder, and forming a slurry.

According to the solid electrolyte of the present invention, the main component is represented by the general formula (La _{2 / 3-x} Li _3x ) _m TiO ₃ (provided that 0.99 ≦ m ≦ 1.10, 0.01 ≦ x ≦ 0.167). ), And Mn is contained in a range of 0.1 to 5 parts by mole with respect to 100 parts by mole of Ti. The decrease can be suppressed, whereby a solid electrolyte having a desired capacitance and good insulating properties can be obtained.

  According to the multilayer electronic component of the present invention, the solid electrolyte layer and the internal electrode layer are alternately stacked, and the internal electrode layer is formed of a conductive material mainly composed of a base metal material, Since the solid electrolyte layer is formed of any of the solid electrolytes described above, and the internal electrode layer and the solid electrolyte layer are baked in a reducing atmosphere so that the base metal material is not oxidized, the base metal material Can be prevented from being oxidized, and the solid electrolyte can be prevented from exhibiting electronic conductivity, whereby a multilayer electronic component having a desired large capacitance and a good specific resistance can be obtained. .

In addition, according to the method for manufacturing a multilayer electronic component of the present invention, the synthesis step includes the synthesis step, the green sheet manufacturing step, the conductive film formation step, the laminate formation step, and the firing step, and the synthesis step includes the solid electrolyte. In the general formula (La _{2 / 3-x} Li _3x ) _m TiO ₃ , m is 0.99 to 1.10, x is 0.01 to 0.167, and Mn is Ti100. The step of weighing each of the Li compound, the La compound, the Ti compound and the Mn compound so as to be 0.1 to 5 mol parts relative to the mol parts, and the firing step includes oxidizing the base metal material Since it is fired in a reducing atmosphere that does not, even if the green sheet and the conductive film are fired simultaneously, the increase in specific resistance can be suppressed, the desired large capacitance, and good insulation Laminated ceramic core Multilayer electronic component of similar stacked structure capacitor can be easily obtained.

1 is a perspective view showing an embodiment of a multilayer solid ion capacitor as a multilayer electronic component formed using a solid electrolyte according to the present invention. It is sectional drawing of FIG.

  Next, an embodiment of the present invention will be described in detail.

The solid electrolyte as one embodiment of the present invention is a composite having a perovskite crystal structure (general formula A _m BO ₃ ) whose main component is represented by the general formula (La _{2 / 3-x} Li _3x ) _m TiO _3. Contains oxides.

  Here, the molar ratio m of (La, Li) constituting the A site and Ti constituting the B site, and the molar content of La are (2 / 3-x), and the molar content of Li is 3x. X (hereinafter referred to as “substitution molar amount x of Li”) satisfies the following mathematical formulas (1) and (2).

0.99 ≦ m ≦ 1.10 (1)
0.01 ≦ x ≦ 0.167 (2)
And this solid electrolyte contains Mn in 0.1-5 mol part with respect to 100 mol part of Ti.

  Therefore, this solid electrolyte can be represented by the following general formula (A).

100 (La _{2 / 3-x} Li _3x ) _m TiO ₃ + aMn (A)
Here, the molar ratio m, the substituted molar amount x of Li, and the contained molar amount a of Mn satisfy Expressions (1) to (3).

0.99 ≦ m ≦ 1.10 (1)
0.01 ≦ x ≦ 0.167 (2)
0.1 ≦ a ≦ 5 (3)
That is, the main component (La _{2 / 3-x} Li _3x ) _m TiO ₃ (hereinafter referred to as “LLT”) is an oxide-based solid having a perovskite-type crystal structure in which Li is a conductive ion. Widely known as an electrolyte.

And as described in the section of “Background Art”, by reducing the thickness of the solid electrolyte, an electric field is applied to the entire solid electrolyte, and the charge in the vicinity of one electrode can move to the vicinity of the other electrode. It is possible to generate extremely large polarization, increase the charge accumulated in each electrode, and obtain a larger capacitance than conventional dielectric materials such as BaTiO _3. Become.

  On the other hand, when an attempt is made to construct a stacked solid ion capacitor using a solid electrolyte, the internal electrode material and the solid electrolyte material are usually fired simultaneously in consideration of productivity and the like. Moreover, it is desirable to use an inexpensive base metal material such as Ni as the internal electrode material.

  Therefore, in order to fire the solid electrolyte material and the base metal material simultaneously, it is necessary to fire in a reducing atmosphere in which the base metal material is not oxidized.

  However, when the solid electrolyte is formed only by LLT, if firing is performed in a reducing atmosphere in which the base metal material is not oxidized, the LLT exhibits electron conductivity, and the specific resistance is lowered, leading to a decrease in insulation.

  Therefore, in the present invention, a predetermined amount of Mn component is added to the LLT to contain Mn in the solid electrolyte. That is, when MLT-added LLT is co-fired with a base metal material in a reducing atmosphere, Mn is replaced with a part of Ti, but Mn is reduced and its valence is reduced, and oxygen vacancies are formed at that time. It is formed. And since this oxygen vacancy has the effect | action which suppresses the detachment | desorption of oxygen in a crystal lattice, it is thought that reduction | restoration of Ti is suppressed and it becomes possible to suppress expression of electronic conductivity.

  By adding Mn to the LLT in this way, it is possible to suppress the expression of electron conductivity in the solid electrolyte, and thus it is possible to suppress a decrease in specific resistance, while maintaining a desired large capacitance while maintaining an insulating property. A good solid electrolyte can be obtained.

  In addition, as described above, this solid electrolyte can obtain a larger specific resistance than the case where it is fired in an air atmosphere by containing a predetermined amount of Mn in LLT and firing it in a reducing atmosphere. it can.

  In other words, when MLT-added LLT is fired in an air atmosphere, Mn is oxidized and its valence increases, so even if Mn is replaced with a part of Ti, oxygen vacancies are not formed in the crystal lattice. For this reason, the reduction of Ti cannot be suppressed, and the specific resistance is reduced as compared with the case of firing in a reducing atmosphere.

  Accordingly, the MLT-added LLT can increase the specific resistance as compared with the case of firing in an air atmosphere by firing in a reducing atmosphere. Therefore, the present solid electrolyte has an insulating property other than the multilayer solid ion capacitor. The present invention can also be applied to various electronic components that are required.

  Next, the reason why the molar ratio m, the substitution molar amount x of Li, and the molar part a of Mn with respect to 100 molar parts of the main component are limited to the ranges of the mathematical formulas (1) to (3) will be described.

(1) Molar ratio m
The molar ratio m is 1.000 in the stoichiometric composition, but it is also preferable to make the A site excessive or the B site excessive as necessary.

  However, when the molar ratio m is less than 0.99, the molar content of Ti becomes excessive. For this reason, in order to compensate the charge balance, the valence of Ti is changed from tetravalent to trivalent. As a result, it is considered that the electronic conductivity is likely to occur and the insulating property may be lowered.

  On the other hand, when the molar ratio m exceeds 1.10, the Ti content molar amount decreases. For this reason, A site defects increase, and in this case as well, electron conductivity is likely to occur, which may lead to a decrease in insulation.

  Therefore, in the present embodiment, they are blended so that the molar ratio m is 0.99 to 1.10.

(2) Li substitution molar amount x
By substituting a part of La with Li, Li ions move in the solid electrolyte, and a large capacitance can be obtained.

  However, if the substitution molar amount x of Li is less than 0.01, the substitution molar amount x of Li decreases, and therefore sufficient insulation cannot be obtained.

  On the other hand, if the substitution molar amount x of Li exceeds 0.167, the content molar amount of Li becomes excessive, and even when baked in a reducing atmosphere, electron conductivity is exhibited, and there is a possibility that the insulation is lowered.

  Therefore, in the present embodiment, the substitution molar amount x of Li is blended so as to be 0.01 to 0.167.

(3) Mn content molar amount a
By including Mn in the solid electrolyte, even if firing in a reducing atmosphere, the expression of electron conductivity is suppressed, and it is possible to suppress a decrease in insulation. For that purpose, the molar amount a of Mn is required to be at least 0.1 mol part per 100 mol parts of Ti.

  However, if the molar amount a of Mn exceeds 5 parts by mole with respect to 100 parts by mole of Ti, the molar amount of Mn becomes excessive, causing a significant decrease in capacitance and firing in a reducing atmosphere. However, it is not preferable because it causes a decrease in insulation.

  Therefore, in the present embodiment, the molar amount a of Mn is blended so as to be 0.1 to 5 parts by mole with respect to 100 parts by mole of Ti.

In particular, when the molar amount a of Mn is 0.1 to 1 part by mole with respect to 100 parts by mole of Ti, the insulation is good and the dielectric constant is much larger than conventional dielectric materials such as BaTiO _3. Can be obtained.

  Thus, in this embodiment, since the general formula (A) satisfies the mathematical formulas (1) to (3), even if firing in a reducing atmosphere in which a base metal material such as Ni is not oxidized, the ratio A decrease in resistance can be suppressed, and thereby a solid electrolyte having good insulation and at least a large capacitance equal to or higher than that of a conventional dielectric material can be obtained.

  In addition, the presence form of Mn in a solid electrolyte is not specifically limited. That is, it is considered that Mn is preferably dissolved in the LLT to some extent, but Mn that segregates at the crystal grain boundary or the crystal triple point may exist.

  Next, the manufacturing method of the said solid electrolyte is explained in full detail.

First, a Li compound such as Li ₂ CO ₃ , a La compound such as La (OH) ₃ , and a Ti compound such as TiO ₂ are prepared as raw materials. These raw materials are weighed so that the general formula (A) satisfies the formulas (1) and (2), pure water is added, wet pulverized, uniformly dispersed and then dried. The powder is calcined to produce a main component powder.

Next, a Mn compound such as MnCO ₃ is prepared as another raw material. Then, the Mn compound is weighed and added to the main component powder so that the general formula (A) satisfies the formula (3), and further, additives such as a binder, a surfactant and a plasticizer are mixed with the solvent, and dispersed. The solid electrolyte material is slurried.

  Here, the binder, the solvent, the plasticizer and the like are not particularly limited. For example, the binder is a high molecular organic binder such as polyvinyl butyral resin, the solvent is an organic solvent such as ethanol or n-butyl acetate, As the plasticizer, dibutyl phthalate or the like can be used.

  Then, the slurry solid electrolyte material is subjected to a forming process using a forming process method such as a doctor blade method to produce a green sheet.

  Next, the green sheet is punched to obtain a molded body having a predetermined thickness.

Next, the compact is subjected to a reducing atmosphere in which the base metal material does not oxidize, for example, in a reducing atmosphere made of H ₂ —N ₂ —H ₂ O gas having an oxygen partial pressure of 1.0 × 10 ⁻¹⁴ MPa. A baking treatment is performed at a temperature of ˜1200 ° C., thereby producing a solid electrolyte.

  As described above, in the present embodiment, the Li compound, the La compound, and the Ti compound are weighed and calcined so that the general formula (A) satisfies the mathematical formulas (1) and (2) to produce the main component powder. Then, a predetermined amount of Mn compound is added to the main component powder to form a slurry so that the general formula (A) satisfies the formula (3), and firing is performed in a predetermined reducing atmosphere. It is possible to obtain a solid electrolyte that has better insulation than the case of firing in an atmosphere and that has a capacitance equal to or higher than that of the dielectric material.

  FIG. 1 is a perspective view showing an embodiment of a multilayer solid ion capacitor as a multilayer electronic component using a solid electrolyte according to the present invention, and FIG. 2 is a cross-sectional view of FIG.

  In this multilayer solid ion capacitor, external electrodes 2 a and 2 b are formed at both ends of a component body 1.

  In the component body 1, solid electrolyte layers 3 made of a solid electrolyte and internal electrode layers 4 mainly composed of a base metal material are alternately laminated. Of the internal electrode layers 4, one internal electrode layer 4a is electrically connected to one external electrode 2a, and the other internal electrode layer 4b is electrically connected to the other external electrode 2b.

  The multilayer solid ion capacitor is formed by firing the solid electrolyte layer 3 and the internal electrode layer 4 in a reducing atmosphere in which the base metal material is not oxidized.

  Here, the base metal material forming the main component of the internal electrode layer 4 is not particularly limited, but it is usually preferable to use Ni which is inexpensive and has good conductivity.

  The solid electrolyte layer 3 has a larger capacitance as the layer is thinner. Therefore, it is desirable to make the layer as thin as possible, and the thickness is preferably 0.8 to 3.0 μm.

  In the multilayer solid ion capacitor formed in this way, when an electric field is applied to the external electrodes 2a and 2b, the electric field is applied to the entire thin solid electrolyte layer 3, thereby sandwiching the solid electrolyte layer 3 therebetween. Thus, a capacitance is formed between the electrodes 4a and 4b. In addition, since extremely large polarization occurs due to Li ions moving in the solid electrolyte layer 3, the charge accumulated in each internal electrode layer 4a, 4b increases, and thereby a stacked type having a remarkably large capacitance. A solid ion capacitor can be obtained.

  In this multilayer solid ion capacitor, the internal electrode layer 4 is formed of a conductive material whose main component is a base metal material, and the solid electrolyte layer 3 is formed of the solid electrolyte described above. Since the electrolyte layer 3 is baked in a reducing atmosphere in which the base metal material does not oxidize, it is possible to suppress the expression of electron conductivity, and thereby, the stacked solid ion having a large capacitance and good insulating properties. A capacitor can be obtained.

  Next, a method for manufacturing this multilayer solid ion capacitor will be described.

  First, a green sheet is produced by the same method as the manufacturing procedure of the solid electrolyte.

  Next, a conductive paste mainly containing a base metal material such as Ni is prepared. Then, a conductive paste is applied on the green sheet to form a conductive film having a predetermined pattern. And the green sheet in which the electrically conductive film was formed is laminated | stacked suitably in a predetermined direction, the green sheet in which the electrically conductive film is not formed is distribute | arranged to the uppermost layer, it heats and pressurizes, and a laminated body is produced.

Next, the laminate is cut to a predetermined size, and then placed in a cocoon (sheath). In a reducing atmosphere where the base metal material is not oxidized as described above, for example, the oxygen partial pressure is 1.0 × 10 ⁻¹⁴ MPa. In a reducing atmosphere composed of H ₂ —N ₂ —H ₂ O gas, firing treatment is performed at a temperature of 1050 to 1200 ° C., whereby the solid electrolyte layer 3 and the internal electrode layer 4 mainly composed of a base metal material are formed. The component bodies 1 that are alternately stacked are obtained.

  Then, an external electrode conductive paste is prepared, and the external electrode conductive paste is applied to both ends of the component body 1 and baked to form the external electrodes 2a and 2b. Produced.

  As described above, according to the present manufacturing method, even if the green sheet and the conductive film are co-fired, the specific resistance does not increase, the laminate has a good capacitance and a good insulating property. A multilayer solid ion capacitor having a multilayer structure similar to a ceramic capacitor can be obtained.

The present invention is not limited to the above embodiment. The present solid electrolyte only needs to be prepared so that at least the general formula (A) forming the main component satisfies the formulas (1) to (3), and does not affect the insulation and the capacitance. Therefore, an appropriate amount of additives such as Al ₂ O ₃ and SiO ₂ may be added as necessary.

  In the above embodiment, the Mn compound is added to the main component powder made of LLT. However, even if the Mn compound is weighed simultaneously with the Li compound, La compound, and Ti compound in the initial raw material weighing stage. Good.

  Next, examples of the present invention will be specifically described.

First, Li ₂ CO ₃ , La (OH) ₃ , and TiO ₂ having a purity of 99.9% or more were prepared as raw materials. Then, in (La _{2 / 3-x} Li _3x ) _m TiO ₃ , these raw materials were weighed so that the molar ratio m and the substituted molar amount x of Li became the values shown in Table 1 after firing. Subsequently, pure water was added to the weighed product, wet-pulverized and uniformly dispersed, dried, and then calcined at a temperature of 1050 ° C. for 2 hours to prepare a main component powder.

Next, MnCO ₃ , Al ₂ O ₃ and SiO ₂ were prepared. Then, with respect Ti100 molar parts, so that the molar content a of Mn after firing becomes a value shown in Table 1, was added MnCO ₃ as a main component powder, to further 100 moles of the main component parts, _Al 2 O ₃ and Al ₂ O ₃ and SiO ₂ were added to the main component powder so that the content of SiO ₂ was 3.0 mol parts in terms of Al and Si, respectively. Next, the solid electrolyte material was dispersed and slurried together with a polymer organic binder, additives such as a surfactant and a plasticizer, and an organic solvent such as ethanol.

  Thereafter, the slurry solid electrolyte material was subjected to molding using a doctor blade method to obtain a green sheet having a thickness of 1.2 μm.

  Next, green sheets were laminated so that the thickness after firing was about 0.5 mm, and punched out into a disk shape with a diameter of 10 mm, and single plate bodies of sample numbers 1 to 21 were produced.

  On the other hand, a conductive paste using Ni as a base metal material was prepared. And the electrically conductive paste was apply | coated on the said green sheet, and the electrically conductive film of the predetermined pattern was formed. Next, 10 layers of green sheets on which conductive films were formed were stacked, a green sheet on which conductive films were not formed was placed on the top layer, and heated and pressurized to prepare a stack of sample numbers 1 to 21.

Next, the single plate body and the laminated body of Sample Nos. 1 to 21 were each at 1150 ° C. in a reducing atmosphere composed of H ₂ —N ₂ —H ₂ O gas having an oxygen partial pressure of 1.0 × 10 ⁻¹⁴ MPa. Firing was carried out at a temperature for 2 hours to prepare single-plate sintered bodies and laminated sintered bodies in which solid electrolyte layers and internal electrode layers were alternately laminated.

  Further, separately, a single plate sintered body that was fired at 1150 ° C. for 2 hours in an air atmosphere was also produced.

  Subsequently, structural analysis was performed on the single plate sintered body and the laminated sintered body using the XRD method (X-ray diffraction method), and it was confirmed that the main component was made of LLT.

  Next, external electrodes were formed for each of the single plate sintered body and the laminated sintered body.

  That is, for each of the 10 single-plate sintered bodies fired in the reducing atmosphere and the air atmosphere, an In-Ga alloy paste was applied to both main surfaces to form external electrodes. A specific resistance measurement sample was prepared. The external dimensions of the specific resistance measurement samples were 10 mm in diameter and 0.5 mm in thickness.

  Further, for each of the 10 laminated sintered bodies fired in the reducing atmosphere, Ni paste was applied to both ends of the laminated sintered body and baked to form external electrodes, thereby preparing a dielectric constant measurement sample. The outer dimensions of the dielectric constant measurement samples were 3.2 mm in length, 1.6 mm in width, and 1.6 mm in thickness.

(Sample evaluation)
For each of the ten specific resistance measurement samples of sample numbers 1 to 21, a DC voltage of 1.0 V was applied between the external electrodes at room temperature (25 ± 2 ° C.) for 100 seconds, and the DC resistance was measured. And the specific resistance was computed from the measured value and sample size, and the average value of 10 samples was calculated | required.

  For each of the 10 samples for measuring the dielectric constant of sample numbers 1 to 21, the capacitance was measured under room temperature (25 ± 2 ° C.) under the measurement conditions of 1 kHz and 0.5 Vrms. From the above, the dielectric constant was calculated, and the average value of 10 samples was obtained.

  Table 1 shows the component composition and measurement results for each of the sample numbers 1 to 21.

  In Sample Nos. 1 to 3, since the solid electrolyte layer does not contain Mn, the dielectric constant is as high as 21000 or more, and the specific resistance logρ is as high as 6.81 to 7.21 when fired in the air atmosphere. However, when firing in a reducing atmosphere in which Ni does not oxidize, the specific resistance logρ was as low as 4.04 to 4.44. This is because Mn is not contained in the solid electrolyte layer, so that electron conductivity is exhibited, and therefore, the specific resistance logρ is lowered and the insulating property is lowered.

  In Sample No. 4, since the substitution molar amount x of Li is as small as 0.005, even when 3 mol parts of Mn are contained in 100 mol parts of Ti, the specific resistance logρ is as low as 5.90 by firing in a reducing atmosphere. , Could not get enough insulation.

  In Sample No. 10, since the substitution molar amount x of Li is too large as 0.200, even when 3 mol parts of Mn is contained in 100 mol parts of Ti, when it is baked in a reducing atmosphere, the electron conduction occurs and the ratio is increased. The resistance log ρ was as low as 4.30, and sufficient insulation could not be obtained.

  Sample No. 11 had a molar ratio m of 0.98 and an excessive amount of Ti. Therefore, the specific resistance logρ was as low as 5.10 when fired in a reducing atmosphere, and sufficient insulation could not be obtained. . This is because the Ti content is excessive, so that the valence of Ti decreases from 4 to 3 in order to compensate for the charge balance. As a result, electron conductivity is generated in the solid electrolyte layer, and the specific resistance logρ is reduced. This seems to have caused a decline.

  Sample No. 16 has a molar ratio m of 1.15 and a small content of Ti, so that the A-site defects are increased, so that the specific resistance logρ is as low as 5.81 and sufficient insulation is obtained. It was also found that the dielectric constant was as low as 2168, and a sufficient capacitance could not be obtained.

  Sample No. 21 contains 7 M parts excessively with respect to 100 parts by mole of Ti, so that the specific resistance logρ is 3.91 and the dielectric constant is 1869 when fired in a reducing atmosphere. Was also found to be extremely low.

On the other hand, sample numbers 5-9, 12-15, and 17-20 have a molar ratio m of 0.99 to 1.10, a substituted molar amount x of Li of 0.010 to 0.167, and 100 parts by mole of Ti. The Mn content is 0.1 to 5 mole parts, and both are within the scope of the present invention. As a result, the dielectric constant is about 2800 to about 18500, the dielectric constant is equal to or higher than that of conventional BaTiO ₃ , and the specific resistance logρ is 6.80 to 8.15 even when fired in a reducing atmosphere. In other words, it has been found that better insulating properties can be obtained than when firing in the air atmosphere with the same composition.

Further, as apparent from sample numbers 17 to 19, when the molar amount of Mn with respect to 100 mol parts of Ti is 0.1 to 1 mol parts, the relative dielectric constant is about 13,000 to about 18500, which is the conventional BaTiO. It has been found that the dielectric constant is much larger than ₃ , and good insulation can be obtained even when firing in a reducing atmosphere.

  Even when fired in a reducing atmosphere, it is possible to obtain a solid electrolyte having good insulation and large capacitance. This solid electrolyte can be used for simultaneous firing with a conductive material mainly composed of a base metal material such as Ni, and a large-capacity stacked solid ion capacitor using the solid electrolyte can be realized.

1 Parts Element 2a, 2b External Electrode 3 Solid Electrolyte Layer 4 Internal Electrode Layer

Claims (8)

A composite oxide whose main component is represented by the general formula (La _{2 / 3-x} Li _3x ) _m TiO ₃ (where 0.99 ≦ m ≦ 1.10, 0.01 ≦ x ≦ 0.167) Containing,
Mn is contained in the range of 0.1-5 mol part with respect to 100 mol part of said Ti, The solid electrolyte characterized by the above-mentioned.   The solid electrolyte according to claim 1, wherein the Mn is contained in a range of 0.1 to 1 mole part with respect to 100 mole parts of Ti.   The solid electrolyte according to claim 1 or 2, wherein the solid electrolyte is fired in a reducing atmosphere. Solid electrolyte layers and internal electrode layers are alternately stacked,
The internal electrode layer is formed of a conductive material mainly composed of a base metal material,
The solid electrolyte layer is formed of the solid electrolyte according to any one of claims 1 to 3,
The internal electrode layer and the solid electrolyte layer are fired in a reducing atmosphere so that the base metal material is not oxidized.   The multilayer electronic component according to claim 4, wherein the base metal material contains Ni as a main component. A synthesis step of synthesizing a solid electrolyte material using a raw material containing at least a Li compound, a La compound, a Ti compound and a Mn compound as a starting material;
Green sheet production step of forming the solid electrolyte material into a sheet shape to produce a green sheet;
A conductive film forming step of forming a conductive film mainly composed of a base metal material on the surface of the green sheet;
A laminated body forming step of laminating the green sheets on which the conductive film is formed to form a laminated body;
The laminated body is fired, and a solid electrolyte layer containing a composite oxide whose main component is represented by the general formula (La _{2 / 3-x} Li _3x ) _m TiO ₃ and an internal electrode layer mainly containing the base metal material And a firing step of producing a laminated sintered body alternately laminated with,
In the synthesis step, the solid electrolyte layer is such that m in the general formula is 0.99 to 1.10, x is 0.01 to 0.167, and Mn is 100 mol parts of Ti. Including a step of weighing each of the Li compound, the La compound, the Ti compound, and the Mn compound so as to be 0.1 to 5 mol parts,
The method for manufacturing a multilayer electronic component, wherein the firing step is performed in a reducing atmosphere in which the base metal material is not oxidized.   The method for manufacturing a multilayer electronic component according to claim 6, wherein the base metal material contains Ni as a main component. The synthesizing step is a main component powder preparation step of weighing and calcining the Li compound, the La compound, and the Ti compound to prepare a main component powder,
The method for manufacturing a multilayer electronic component according to claim 7, further comprising: a slurrying step of weighing the Mn compound and adding the Mn compound to the main component powder to form a slurry.

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