JP2008227093A - Manufacturing method of multilayer electronic component - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a multilayer electronic component such as a multilayer ceramic capacitor capable of improving acceleration life of an insulation resistance while keeping specific inductive capacity and insulation resistance well even if a dielectric layer is reduced in thickness. <P>SOLUTION: With the use of internal electrode layer paste and dielectric layer paste, a green sheet and an electrode paste layer are alternately stacked to provide a green chip. The manufacturing method of a multilayer electronic component includes a process for baking it. The internal electrode layer paste contains conductor material, titanic acid barium, and 0.2 mols or more of oxide of V against 100 mols of titanic acid barium and/or compound that becomes oxide of V after baking. The dielectric layer paste contains titanic acid barium and oxide of V which is more than 0 mol but less than 0.1 mols against 100 mols of titanic acid barium and/or compound that becomes oxide of V after baking. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a method of manufacturing a multilayer electronic component such as a multilayer ceramic capacitor. More specifically, the present invention relates to an accelerated life of an insulation resistance while maintaining a good dielectric constant and insulation resistance (particularly, insulation resistance at high temperatures). The present invention relates to a method for manufacturing a multilayer electronic component that can be improved.

  A multilayer ceramic capacitor, which is an example of an electronic component, prints internal electrodes in a predetermined pattern using, for example, internal electrode layer paste on a ceramic green sheet formed using a predetermined dielectric layer paste. A green chip obtained by alternately stacking a plurality of sheets and then integrating them is manufactured by simultaneous firing. Since the internal electrode layer of the multilayer ceramic capacitor is integrated with the ceramic dielectric by firing, it is necessary to select a material that does not react with the dielectric material. For this reason, as a material constituting the internal electrode layer, conventionally, an expensive noble metal such as platinum or palladium has been inevitably used.

  However, in recent years, dielectric ceramic compositions that can use inexpensive base metals such as nickel and copper have been developed, and a significant cost reduction has been realized.

  In recent years, there has been a high demand for downsizing of electronic components due to higher density of electronic circuits, and downsizing and increase in capacity of multilayer ceramic capacitors are rapidly progressing. As a result, the dielectric layer of a multilayer ceramic capacitor has been made thinner. Therefore, a dielectric material that can maintain the reliability as a capacitor even if the layer is made thinner is required as a dielectric material constituting the dielectric layer. Yes. In particular, in order to reduce the size and increase the capacity, very high reliability is required for the dielectric material. This is because when the dielectric layer is made thinner for miniaturization and larger capacity, the electric field applied to each dielectric layer becomes stronger when a DC voltage is applied. That is, the deterioration of the insulation resistance (acceleration life of the insulation resistance) in the capacity change with time and the high-temperature load test is remarkably increased.

  On the other hand, in Patent Document 1, in order to improve temperature characteristics and life characteristics, two or more kinds of specific component elements having different concentrations are used as the dielectric material constituting the dielectric layer of the multilayer ceramic capacitor. A method using a dielectric material composed of ceramic particles has been proposed. In this Patent Document 1, in a specific embodiment, a predetermined amount of Mn, Cr, Co, and V is added to the internal electrode layer paste, thereby forming a dielectric material constituting the dielectric layer. The aspect which changed the component density | concentration of the ceramic particle | grains in is disclosed.

  However, in Patent Document 1, V is not added at all in the dielectric paste constituting the dielectric layer, and therefore V is not substantially contained in the fired dielectric layer. The result is the inclusion of ceramic particles. For this reason, the multilayer ceramic capacitor described in Patent Document 1 has a problem in that the variation in the life characteristics between samples becomes large, resulting in poor reliability.

Japanese Patent Application Laid-Open No. 2003-1000054

  The present invention has been made in view of such a situation, and even when the thickness of the dielectric layer is reduced, the dielectric constant and the insulation resistance (particularly, the insulation resistance at high temperatures) are maintained while maintaining the insulation resistance. It is an object of the present invention to provide a multilayer electronic component such as a multilayer ceramic capacitor capable of improving the accelerated life of the multilayer ceramic capacitor.

  In order to improve the accelerated lifetime of insulation resistance, it is common to add a donor component such as a rare earth element into the dielectric layer. On the other hand, the addition of rare earth elements increases the temperature characteristics of the capacity, particularly the lowering of the capacity on the high temperature side, so that an oxide of V or the like is also added as a donor component other than the rare earth. However, when the oxide of V having the effect of improving the life characteristics is added, the relative dielectric constant is lowered, so that the amount added in the dielectric layer cannot be increased too much. For this reason, it has been difficult to achieve both the relative dielectric constant and the accelerated lifetime of the insulation resistance.

  On the other hand, the present inventors have conducted intensive studies in order to achieve the above object, and as a result, when manufacturing a multilayer electronic component such as a multilayer ceramic capacitor, a dielectric layer that constitutes a dielectric layer. The ratio of the compound of V to be contained in the body layer paste is in the range of more than 0 mole and 0.1 mole or less with respect to 100 moles of barium titanate, and a predetermined amount of paste is added to the internal electrode layer paste. It has been found that the above object can be achieved by containing the compound of V, and the present invention has been completed based on this finding.

That is, according to the present invention, a method of manufacturing a multilayer electronic component in which internal electrode layers and dielectric layers are alternately stacked,
Using the internal electrode layer paste and the dielectric layer paste, a green chip is obtained in which a green sheet that becomes the dielectric layer after firing and an electrode paste layer that becomes the internal electrode layer after firing are alternately laminated. Process,
Firing the green chip,
The internal electrode layer paste contains a conductive material, barium titanate, a V oxide and / or a compound that becomes a V oxide after firing,
In the internal electrode layer paste, the ratio of the V oxide and / or the compound that becomes a V oxide after firing is 0.2 mol or more in terms of V ₂ O _{5 with} respect to 100 mol of the barium titanate. And
The dielectric layer paste contains barium titanate and a V oxide and / or a compound that becomes a V oxide after firing,
In the dielectric layer paste, the ratio of the oxide of V and / or the compound that becomes an oxide of V after firing is more than 0 mol in terms of V ₂ O _{5 with} respect to 100 mol of the barium titanate, Provided is a method for producing a multilayer electronic component of 0.1 mol or less.

Preferably, the ratio of the oxide and / or become oxides of V after firing compound of V with respect to the 100 mol of barium titanate in the internal electrode layer paste, and E _V moles,
The ratio of the oxide and / or become oxides of V after firing compound of V with respect to the 100 mol of barium titanate in the dielectric layer paste, the case of the D _V moles,
Relationship between the _{E V} and _{D V is} the E _V / _D V ≧ 5.

  Preferably, the ratio of the oxide of V and / or the compound which becomes an oxide of V after firing to 100 mol of the barium titanate in the internal electrode layer paste is less than 1 mol.

  The multilayer electronic component according to the present invention is not particularly limited, and examples thereof include multilayer ceramic capacitors, piezoelectric elements, chip inductors, chip varistors, chip thermistors, chip resistors, and other surface mount (SMD) chip electronic components. .

  According to the method for manufacturing a multilayer electronic component of the present invention, since the internal electrode layer paste and the dielectric layer paste having the above-described predetermined configuration are used, even when the thickness of the dielectric layer is reduced, It is possible to provide a multilayer electronic component such as a multilayer ceramic capacitor in which the accelerated lifetime of the insulation resistance is improved while maintaining a good dielectric constant and insulation resistance (particularly, insulation resistance at high temperatures).

  In particular, according to the present invention, the ratio of the compound of V (the oxide of V and / or the compound that becomes an oxide of V after firing) to be included in the dielectric layer paste that constitutes the dielectric layer, Since the range of 0.1 mol or less with respect to 100 mol of barium titanate, it is possible to effectively prevent a decrease in the dielectric constant due to the addition of the compound of V, thereby improving the dielectric constant. It can be. In addition, by including a V compound in the dielectric layer paste, the insulation resistance, particularly the insulation resistance at high temperatures, can be improved, and further, the accelerating life of the insulation resistance varies between samples. Can also be effectively prevented. That is, the high temperature load life characteristic can be stabilized.

  In addition, in the present invention, the internal electrode layer paste that constitutes the internal electrode layer contains barium titanate and a V compound as additive materials, and the V in the internal electrode layer paste The ratio of the compound is set to 0.2 mol or more with respect to 100 mol of barium titanate. Therefore, it is possible to improve the accelerated life of the insulation resistance while keeping the relative dielectric constant and the insulation resistance good.

Hereinafter, the present invention will be described based on embodiments shown in the drawings.
FIG. 1 is a cross-sectional view of a multilayer ceramic capacitor according to an embodiment of the present invention.
FIG. 2 is a graph showing the failure time of each evaluation sample at the time of evaluating the accelerated life of the insulation resistance of the multilayer ceramic capacitor according to the example and the comparative example of the present invention.

Multilayer Ceramic Capacitor First, before describing the manufacturing method of the present invention, a multilayer ceramic capacitor as an embodiment obtained by the manufacturing method of the present invention will be described.
As shown in FIG. 1, a multilayer ceramic capacitor 1 according to an embodiment of the present invention includes a capacitor body 10 having a configuration in which dielectric layers 2 and internal electrode layers 3 are alternately stacked. A pair of external electrodes 4, 4 are formed at both ends of the capacitor body 10 and are electrically connected to the internal electrode layers 3 arranged alternately in the body 10. The internal electrode layers 3 are laminated so that the side end faces are alternately exposed on the surfaces of the two opposite ends of the capacitor body 10. The pair of external electrodes 4, 4 are formed at both ends of the capacitor body 10 and are connected to the exposed end surfaces of the alternately arranged internal electrode layers 3 to constitute a capacitor circuit.

  The outer shape and dimensions of the capacitor body 10 are not particularly limited and can be appropriately set depending on the application. Usually, the outer shape is substantially a rectangular parallelepiped shape, and the dimensions are usually vertical (0.4 to 5.6 mm) × It can be about horizontal (0.2 to 5.0 mm) × height (0.2 to 2.5 mm).

Dielectric layer 2
The dielectric layer 2 is composed of a dielectric ceramic composition. The dielectric ceramic composition according to the present invention contains a main component containing at least barium titanate and an oxide of V as a subcomponent.

The main component barium titanate is represented by the composition formula Ba _m TiO _{2 + m} , _m in the composition formula is 0.990 <m <1.010, and the ratio of Ba to Ti is 0.990 < Those with Ba / Ti <1.010 are preferably used. At this time, the amount of oxygen (O) may be slightly deviated from the stoichiometric composition of the above formula.

As a subcomponent contained in the dielectric layer 2, it is sufficient if it contains at least a V oxide. The ratio of the oxide of V in the dielectric layer 2 is not particularly limited, but is preferably 0.03 to 0.06 mol in terms of V ₂ O _{5 with} respect to 100 mol of barium titanate as the main component. It is. Since the multilayer ceramic capacitor according to the present embodiment is manufactured by the manufacturing method of the present invention described later, the V oxide ratio in the vicinity of the internal electrode layer 3 is related to the ratio of the V oxide in the dielectric layer 2. It is considered that the ratio is higher than the ratio of the oxide of V in the central portion of the dielectric layer (the central portion in the thickness direction).

  Moreover, as a subcomponent contained in the dielectric layer 2, a subcomponent other than the V oxide may be contained as necessary in addition to the above-mentioned V oxide. Such subcomponents include Sr, Zr, Y, La, Ce, Pr, Nd, Pm, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu, Mo, Zn, Cd, One or more types selected from oxides of Ti, Sn, W, Ba, Ca, Mn, Mg, Cr, Si, Li, B, and P are exemplified. Various properties can be improved by adding subcomponents other than the oxide of V as subcomponents.

For example, the subcomponents other than the oxide of V can preferably have the following composition and addition amount.
That is, at least one selected from MgO, CaO, BaO and SrO is 0.1 to 5 mol with respect to 100 mol of barium titanate,
0.1 to 12 mol of a component mainly containing SiO ₂ and containing MO (wherein M is at least one selected from Mg, Ca, Ba and Sr) with respect to 100 mol of barium titanate,
An oxide of R (wherein R is at least one selected from Y, La, Ce, Pr, Nd, Pm, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb and Lu), 0.1 to 10 mol in terms of R with respect to 100 mol of barium titanate,
0.05 to 1.0 mol of at least one selected from MnO and Cr ₂ O _{3 with} respect to 100 mol of barium titanate,
And the amount of addition.

  By setting the subcomponents other than the oxide of V to the above composition and addition amount, it is possible to perform low-temperature firing while keeping the relative dielectric constant high, and to improve the capacity-temperature characteristics. However, in the present invention, the composition of the dielectric layer 2 is not limited to the above.

  Various conditions such as the number and thickness of the dielectric layers 2 shown in FIG. 1 may be appropriately determined according to the purpose and application. In this embodiment, the thickness of the dielectric layer 2 is preferably 5 μm or less. The layer is preferably thinned to 2 μm or less. Although the minimum of thickness is not specifically limited, For example, it is about 0.5 micrometer.

  The number of laminated dielectric layers 2 is not particularly limited, but is preferably 20 or more, more preferably 50 or more, and particularly preferably 100 or more. The upper limit of the number of stacked layers is not particularly limited, but is about 2000, for example.

Internal electrode layer 3
The conductive material contained in the internal electrode layer 3 is not particularly limited, but a relatively inexpensive base metal can be used because the constituent material of the dielectric layer 2 has reduction resistance. As the base metal used as the conductive material, Ni or Ni alloy is preferable. The Ni alloy is preferably an alloy of Ni and one or more elements selected from Mn, Cr, Co and Al, and the Ni content in the alloy is preferably 95% by weight or more. In addition, in Ni or Ni alloy, various trace components, such as P, may be contained about 0.1 wt% or less. The thickness of the internal electrode layer 3 may be appropriately determined according to the application and the like, but is usually 0.1 to 3 μm, particularly preferably about 0.2 to 2.0 μm.

External electrode 4
The conductive material contained in the external electrode 4 is not particularly limited, but in the present invention, inexpensive Ni, Cu, and alloys thereof can be used. The thickness of the external electrode 4 may be appropriately determined according to the application and the like, but is usually preferably about 10 to 50 μm.

Manufacturing Method of Multilayer Ceramic Capacitor The multilayer ceramic capacitor of the present embodiment is the same as the conventional multilayer ceramic capacitor. After producing a green chip by a normal printing method or sheet method using a paste and firing it, the external electrode It is manufactured by printing or transferring and baking. Hereinafter, the manufacturing method will be specifically described.

First, a dielectric ceramic composition powder contained in a dielectric layer paste for forming the dielectric layer 2 shown in FIG. 1 is prepared. In the present embodiment, the dielectric ceramic composition powder contained in the dielectric layer paste contains at least barium titanate and a compound that becomes an oxide of V and / or becomes an oxide of V after firing. Use. The content of the V oxide and / or the compound that becomes the V oxide after firing is more than 0 mol and 0.1 mol or less in terms of V ₂ O _{5 with} respect to 100 mol of barium titanate, Preferably they are 0.03 mol or more and 0.06 mol or less.

  If no oxide of V and / or a compound that becomes an oxide of V after firing is added to the dielectric layer paste, ceramic particles substantially free of the oxide of V are contained in the dielectric layer after firing. As a result, the variation in the accelerated life of the insulation resistance between samples becomes large, and the reliability becomes poor. On the other hand, if the amount is too large, the relative dielectric constant will be lowered, and it will not be possible to cope with a reduction in size and capacity.

  Examples of the compound that becomes an oxide of V after firing include carbonates, oxalates, nitrates, hydroxides, organometallic compounds, and the like, and these can also be used in combination.

  Further, if necessary, the dielectric ceramic composition powder may contain raw materials for various subcomponents other than the oxide of V described above. In this case, the above-described oxide, a mixture thereof, or a composite oxide can be used. In addition, various compounds that become the above-described oxide or composite oxide by firing, such as carbonate, oxalate, and nitrate. , Hydroxides, organometallic compounds and the like may be selected as appropriate and used in combination. What is necessary is just to determine content of each compound in a dielectric ceramic composition powder so that it may become a desired composition after baking.

  Next, a dielectric layer paste is manufactured using the obtained dielectric ceramic composition powder. The dielectric layer paste may be an organic paint obtained by kneading a dielectric ceramic composition powder and an organic vehicle, or may be a water-based paint.

  An organic vehicle is obtained by dissolving a binder in an organic solvent. The binder used for the organic vehicle is not particularly limited, and may be appropriately selected from usual various binders such as ethyl cellulose and polyvinyl butyral. Further, the organic solvent to be used is not particularly limited, and may be appropriately selected from various organic solvents such as terpineol, butyl carbitol, acetone, toluene, and the like, depending on a method to be used such as a printing method or a sheet method.

  Further, when the dielectric layer paste is used as a water-based paint, a water-based vehicle in which a water-soluble binder, a dispersant, or the like is dissolved in water and a dielectric ceramic composition powder may be kneaded. The water-soluble binder used for the water-based vehicle is not particularly limited, and for example, polyvinyl alcohol, cellulose, water-soluble acrylic resin, or the like may be used.

  There is no restriction | limiting in particular in content of an organic vehicle, What is necessary is just to set normal content, for example, a binder about 1 to 5 weight% and a solvent about 10 to 50 weight%. In addition, the dielectric layer paste may contain additives selected from various dispersants, plasticizers, dielectrics, insulators and the like as required. The total content of these is preferably 10% by weight or less.

  Next, an internal electrode layer paste for forming the internal electrode layer 3 shown in FIG. 1 is prepared. The internal electrode layer paste contains at least a conductor material, barium titanate as an additive component, and a V oxide and / or a compound that becomes a V oxide after firing.

  Examples of the conductor material include conductive materials composed of the various conductive metals and alloys described above, and various oxides, organometallic compounds, resinates, and the like that become the conductive materials described above after firing.

  Further, as the barium titanate contained as an additive component, the same one as used in the above-described dielectric layer paste may be used. Barium titanate as an additive component has an effect of suppressing sintering of the conductor material in the firing process. The addition amount of barium titanate in the internal electrode layer paste is not particularly limited, but is preferably 10 to 40 parts by weight with respect to 100 parts by weight of the conductor material. If the content of barium titanate is too small, the effect of suppressing the sintering becomes insufficient, the conductor material becomes spheroidized during the firing process, and electrode breakage is likely to occur. On the other hand, if the amount is too large, the content of the conductor material in the internal electrode layer paste is relatively reduced, and similarly, electrode breakage is likely to occur.

  As the V oxide and / or the compound that becomes the V oxide after firing as the additive component, the same compounds as those used for the dielectric layer paste may be used. By including a predetermined amount of a V oxide and / or a compound that becomes a V oxide after firing in the internal electrode layer paste, the accelerated life of the insulation resistance can be improved.

The content of the V oxide in the internal electrode layer paste and / or the compound that becomes the V oxide after firing is V ₂ O _{5 with} respect to 100 mol of barium titanate contained in the internal electrode layer paste. In conversion, it is 0.2 mol or more, preferably 0.2 mol or more and less than 1 mol, more preferably 0.25 mol or more and 0.75 mol or less. If the content of the V oxide and / or the compound that becomes the V oxide after firing in the internal electrode layer paste is too small, the effect of improving the accelerated life of the insulation resistance cannot be obtained. On the other hand, if the amount is too large, the insulation resistance, particularly the insulation resistance at high temperatures, tends to deteriorate.

  In the present invention, as the dielectric layer paste and the internal electrode layer paste, a paste containing the above-mentioned predetermined amount of a V oxide and / or a compound that becomes a V oxide after firing is used. . The present invention has the greatest feature in this respect. By adopting such a configuration, even when the thickness of the dielectric layer 2 is reduced, the relative permittivity and the insulation resistance (especially at high temperatures). It is possible to improve the accelerated life of the insulation resistance while keeping the insulation resistance) in good condition.

This reason is not necessarily clear, but for example, the following reason can be considered.
That is, by adding the predetermined amount of the V compound (the oxide of V and / or the compound which becomes an oxide of V after firing) together with barium titanate to the internal electrode layer paste, the dielectric layer paste and When firing the green chip manufactured using the internal electrode layer paste, the V compound contained in the internal electrode layer paste diffuses to the dielectric layer 2 side during firing. Then, the V compound contained in the internal electrode layer paste diffuses to the dielectric layer 2 side, so that the dielectric ceramic composition constituting the dielectric layer 2 becomes V in the vicinity of the internal electrode layer 3. The compound content is higher than that in the vicinity of the center of the dielectric layer 2 in the thickness direction. As a result, the entire dielectric layer 2 can be configured such that the content of the V compound is relatively high in the vicinity of the internal electrode layer 3 while keeping the content of the V compound low. As a result, it is considered that the above effects can be achieved. That is, it is considered that the fine structure in the dielectric layer 2, specifically, the distribution of the content of the V compound in the dielectric layer 2 can be controlled, and thereby the above-described effect can be achieved. .

In the present invention, the V oxide contained in the dielectric layer paste and / or the compound that becomes the V oxide after firing, and the V oxide contained in the internal electrode layer paste and / or after firing. The compound to be an oxide of V may be in the above range, but it is more preferable that these ratios have the following relationship. That is, the ratio of the oxide and / or become oxides of V after firing compounds of V with respect to 100 moles of barium titanate in the internal electrode layer paste, and E _V moles of barium titanate in the dielectric layer paste 100 mol the ratio of the oxide and / or become oxides of V after firing compounds of V with respect to the case of the D _V mole, the relationship between E _V and D _V, preferably E _{V /} D _V ≧ 5, more Preferably, 5 ≦ E _V / D _V ≦ 15. The relationship between E _V and D _V With such a relationship, it is possible to further improve the above effects.

  Next, the above-described conductor material, barium titanate, and the oxide of V and / or the compound that becomes an oxide of V after firing are kneaded together with the above-described organic vehicle to prepare an internal electrode layer paste. To do. The content of the organic vehicle may be the same as described above.

  Next, using the dielectric layer paste and internal electrode layer paste prepared by the above method, the green sheet that becomes the dielectric layer 2 after firing and the electrode paste layer that becomes the internal electrode layer 3 after firing alternately Get stacked green chips.

  A method of laminating these is not particularly limited, and examples thereof include a printing method and a sheet method. When the printing method is used, the dielectric layer paste and the internal electrode layer paste are laminated and printed on a substrate such as PET, cut into a predetermined shape, and then peeled from the substrate to obtain a green chip. When the sheet method is used, a dielectric layer paste is used to form a green sheet, the internal electrode layer paste is printed thereon, and these are stacked to form a green chip.

  Before firing, the green chip is subjected to binder removal processing. As the binder removal conditions, the temperature rising rate is preferably 5 to 300 ° C./hour, more preferably 10 to 100 ° C./hour, the holding temperature is preferably 180 to 400 ° C., more preferably 200 to 300 ° C., and the temperature holding time. Is preferably 0.5 to 24 hours, more preferably 5 to 20 hours. The binder removal atmosphere is preferably in the air.

Next, the green chip subjected to the binder removal process is fired. The atmosphere at the time of green chip firing may be appropriately determined according to the type of conductive material in the internal electrode layer paste, but when a base metal such as Ni or Ni alloy is used as the conductive material, the oxygen content in the firing atmosphere The pressure is preferably 10 ⁻⁹ to 10 ⁻⁴ Pa. When the oxygen partial pressure is less than the above range, the conductive material of the internal electrode layer may be abnormally sintered and may be interrupted. Further, when the oxygen partial pressure exceeds the above range, the internal electrode layer tends to be oxidized.

  Moreover, the holding temperature at the time of baking becomes like this. Preferably it is 1000-1400 degreeC, More preferably, it is 1100-1350 degreeC. If the holding temperature is lower than the above range, the densification becomes insufficient. If the holding temperature is higher than the above range, the electrode is interrupted due to abnormal sintering of the internal electrode layer, the capacity temperature characteristic is deteriorated due to diffusion of the constituent material of the internal electrode layer, and the dielectric Reduction of the body porcelain composition is likely to occur.

As other firing conditions, the rate of temperature rise is preferably 100 to 2000 ° C./hour, more preferably 200 to 1000 ° C./hour, and the temperature holding time is preferably 0.5 to 8 hours, more preferably 1 to 3 hours. The time and cooling rate are preferably 50 to 500 ° C./hour, more preferably 200 to 300 ° C./hour. Further, the firing atmosphere is preferably a reducing atmosphere, and as the atmosphere gas, for example, a mixed gas of N ₂ and H ₂ is preferably used by humidification.

  When firing in a reducing atmosphere, it is preferable to anneal the capacitor element body. Annealing is a process for re-oxidizing the dielectric layer, and this can significantly increase the IR lifetime, thereby improving the reliability.

The oxygen partial pressure in the annealing atmosphere is preferably 10 ⁻³ Pa or more, particularly preferably 10 ^{−2 to} 10 Pa. When the oxygen partial pressure is less than the above range, it is difficult to reoxidize the dielectric layer, and when it exceeds the above range, the internal electrode layer tends to be oxidized.

  The holding temperature at the time of annealing is preferably 1200 ° C. or less, particularly 500 to 1200 ° C. When the holding temperature is lower than the above range, the dielectric layer is not sufficiently oxidized, so that the IR is low and the high temperature load life is likely to be shortened. On the other hand, when the holding temperature exceeds the above range, not only the internal electrode layer is oxidized and the capacity is lowered, but the internal electrode layer reacts with the dielectric substrate, the capacity temperature characteristic is deteriorated, the IR is lowered, and the high temperature is increased. The load life is likely to decrease.

As other annealing conditions, the rate of temperature rise is preferably 100 to 900 ° C./hour, more preferably 200 to 900 ° C./hour, and the temperature holding time is preferably 0.5 to 12 hours, more preferably 1 to 10 hours. The time and cooling rate are preferably 50 to 600 ° C./hour, more preferably 100 to 300 ° C./hour. Further, as the annealing atmosphere gas, for example, humidified N ₂ gas or the like is preferably used.

In the above-described binder removal processing, firing and annealing, for example, a wetter or the like may be used to wet the N ₂ gas or mixed gas. In this case, the water temperature is preferably about 5 to 75 ° C.
The binder removal treatment, firing and annealing may be performed continuously or independently.

The capacitor element body obtained as described above is subjected to end face polishing by, for example, barrel polishing or sand blasting, and the external electrode paste is printed or transferred and baked to form the external electrode 4. The firing conditions of the external electrode paste are preferably, for example, about 10 minutes to 1 hour at 600 to 800 ° C. in a humidified mixed gas of N ₂ and H ₂ . Then, if necessary, a coating layer is formed on the surface of the external electrode 4 by plating or the like. The external electrode paste is prepared by kneading the above-mentioned organic vehicle with various conductive metals and alloys as described above, or various oxides, organometallic compounds, resinates, etc. that become the above-mentioned conductive materials after firing. Can be prepared.
The multilayer ceramic capacitor of the present invention thus manufactured is mounted on a printed circuit board by soldering or the like and used for various electronic devices.

  As mentioned above, although embodiment of this invention has been described, this invention is not limited to the embodiment mentioned above at all, and can be variously modified within the range which does not deviate from the summary of this invention.

  For example, in the above-described embodiment, the multilayer ceramic capacitor is exemplified as the multilayer electronic component according to the present invention. However, the multilayer electronic component according to the present invention is not limited to the multilayer ceramic capacitor, and is manufactured by the above method. Anything can be used.

  Hereinafter, although this invention is demonstrated based on a more detailed Example, this invention is not limited to these Examples.

Example 1
Preparation of Dielectric Layer Paste First, as a starting material, BaTiO ₃ powder (average particle diameter: 0.2 μm) as a main component material and V ₂ O ₅ , Y ₂ O ₃ , SiO ₂ , MgO as additive components, MnO was prepared. Incidentally, the amount of additive component, BaTiO ₃ as the main component with respect to 100 moles, were as follows.
V ₂ O ₅ : 0.03 mol Y ₂ O ₃ : 0.5 mol SiO ₂ : 0.5 mol MgO: 1.5 mol MnO: 0.2 mol And these main component raw materials and raw materials for additive components Was mixed with a ball mill for 16 hours and then dried to prepare a dielectric ceramic composition powder.

  Next, the dielectric ceramic composition powder prepared above: 100 parts by weight, butyral resin: 4.8 parts by weight, toluene: 10 parts by weight, ethyl acetate 70 parts by weight, mineral spirit: 6 parts by weight Acetone: 4 parts by weight was mixed with a ball mill and formed into a paste to obtain a dielectric layer paste.

Preparation of Internal Electrode Layer Paste Separately from the above, an internal electrode layer paste was prepared by the following method. That is, first, Ni particles: 100 parts by weight, additive barium titanate: 20 parts by weight and a predetermined amount of V ₂ O ₅ , an organic vehicle (ethyl cellulose 8 parts by weight dissolved in butyl carbitol 92 parts by weight) Things): 40 parts by weight and butyl carbitol: 10 parts by weight were kneaded with three rolls to obtain a paste for an internal electrode layer.
In this example, a plurality of internal electrode layer pastes (sample numbers 1 to 7) were prepared in which the amounts of V ₂ O ₅ added to the internal electrode layer paste were as shown in Table 1. Here, the addition amount of V ₂ O ₅ shown in Table 1 is an addition amount with respect to 100 mol of barium titanate.

The green sheet was formed, fired, and the like, and the obtained dielectric layer paste was used to form a green sheet on the PET film. After the internal electrode paste was printed thereon, the sheet was peeled from the PET film. Next, these green sheets and protective green sheets (not printed with internal electrode layer paste) were laminated and pressure-bonded to obtain green chips.

Next, the green chip produced above was subjected to binder removal processing, firing and annealing under the following conditions to obtain a multilayer ceramic fired body.
The binder removal treatment conditions were temperature rising rate: 32.5 ° C./hour, holding temperature: 260 ° C., temperature holding time: 8 hours, and atmosphere: in the air.
Firing conditions are: temperature rising rate: 200 ° C./hour, holding temperature: 1210 or 1230 ° C., temperature holding time: 2 hours, cooling rate: 200 ° C./hour, atmospheric gas: humidified N ₂ + H ₂ mixed gas (oxygen content) Pressure: 10 ⁻⁶ Pa).
The annealing conditions were as follows: temperature rising rate: 200 ° C./hour, holding temperature: 1050 ° C., temperature holding time: 2 hours, cooling rate: 200 ° C./hour, atmospheric gas: humidified N ₂ gas (oxygen partial pressure: 10 ⁻¹ Pa).
Note that a wetter with a water temperature of 20 ° C. was used for humidifying the atmospheric gas during firing and annealing.

Next, after polishing the end face of the obtained multilayer ceramic fired body by sand blasting, In-Ga was applied as an external electrode to obtain samples (sample numbers 1 to 7) of the multilayer ceramic capacitor shown in FIG. Sample numbers 1 to 7 are samples using pastes having different amounts of V ₂ O ₅ as shown in Table 1 as internal electrode layer pastes.

  The size of the obtained capacitor sample was 3.2 mm × 1.6 mm × 0.6 mm, the number of dielectric layers sandwiched between internal electrode layers was 4, and the thickness of the dielectric layers per layer (interlayer thickness) ) Was about 3.5 μm, and the thickness of the internal electrode layer was 0.9 μm.

  And each evaluation of the dielectric constant ε, the accelerated life of the insulation resistance, and the insulation resistance at high temperature was performed on the obtained capacitor sample by the following methods.

Dielectric constant ε
Capacitor C and dielectric with respect to a capacitor sample under the conditions of a frequency of 1 kHz and an input signal level (measurement voltage) of 0.5 Vrms / μm with a digital LCR meter (YHP 4274A) at a reference temperature of 20 ° C. The loss tan δ was measured. Then, the relative dielectric constant ε (no unit) was calculated from the obtained capacitance. In this example, the value of the relative dielectric constant ε was calculated as an average value of values measured using the number of capacitor samples n = 20. The relative dielectric constant ε is preferably high, and is an important characteristic for producing a small-sized and large-capacity capacitor. The results are shown in Table 1.

Accelerated life of insulation resistance (high temperature load life)
The accelerated life of the insulation resistance was measured by maintaining a DC voltage of 16 V / μm at 180 ° C. with respect to the capacitor sample. In this example, the time from the start of application until the resistance drops by an order of magnitude was defined as the lifetime, and this was performed for 10 capacitor samples, and the average lifetime was calculated. The results are shown in Table 1.

The insulation resistance after applying a DC voltage of 20 V for 1 minute to the insulation resistance capacitor sample at high temperature using an insulation resistance meter (R8340A manufactured by Advantest) was measured under the condition of a temperature of 125 ° C. The insulation resistance (unit: GΩ) at a high temperature is preferably as large as possible. The results are shown in Table 1.

表１中、誘電体層用ペースト中のＶ_２ Ｏ_５ 量（Ｄ_Ｖ）は、誘電体層用ペースト中に含有させるチタン酸バリウム１００モルに対する量であり、また、内部電極層用ペースト中のＶ_２ Ｏ_５ 量（Ｅ_Ｖ）は、内部電極層用ペースト中に含有させるチタン酸バリウム１００モルに対する量であり、さらに、Ｅ_Ｖ ／Ｄ_Ｖ はこれらの比である（以下、表２〜表４も同様）。

In Table 1, the amount of V ₂ O ₅ (D _V ) in the dielectric layer paste is an amount with respect to 100 mol of barium titanate contained in the dielectric layer paste, and the amount of V ₂ O ₅ in the internal electrode layer paste The amount of V ₂ O ₅ (E _V ) is an amount relative to 100 mol of barium titanate contained in the internal electrode layer paste, and E _V / D _V is a ratio thereof (hereinafter, Table 2 to Table 2). 4 is the same).

From Table 1, the _V 2 _{O 5} content in the dielectric layer paste was 0.03 mol, and the _V 2 _{O 5} content in the internal electrode layer paste by a 0.2 to 1 mols It can be confirmed that the accelerated life of the insulation resistance can be improved while keeping the relative dielectric constant good. These samples are samples that satisfy E _V / D _V ≧ 5. On the other hand, when V ₂ O ₅ was not added to the internal electrode layer paste and when the amount of V ₂ O ₅ was 0.1 mol, the accelerated life of insulation resistance was inferior. When the amount of V ₂ O ₅ was 1 mol, the insulation resistance at high temperature tended to decrease.

Example 2
The amount of V ₂ O ₅ in the dielectric layer paste is changed to 0.06 mol with respect to 100 mol of barium titanate contained in the dielectric layer paste, and V is contained in the internal electrode layer paste. _A capacitor sample (sample numbers 11 to 18) was prepared in the same manner as in Example 1 except that the amount of ₂ O _{5 was changed to the} amount shown in Table 2 with respect to 100 moles of barium titanate contained in the internal electrode layer paste. ) And evaluated in the same manner. The results are shown in Table 2.

From Table 2, it can be confirmed that the same tendency is observed even when the amount of V ₂ O ₅ in the dielectric layer paste is 0.06 mol. In Example 2, it can be confirmed that particularly good results are obtained when E _V / D _V ≧ 5.

Example 3
The amount of V ₂ O ₅ in the dielectric layer paste is changed to 0.1 mol with respect to 100 mol of barium titanate contained in the dielectric layer paste, and V is contained in the internal electrode layer paste. _A capacitor sample (sample numbers 21 to 28) was prepared in the same manner as in Example 1 except that the amount of ₂ O _{5 was changed to the} amount shown in Table 3 with respect to 100 moles of barium titanate contained in the internal electrode layer paste. ) And evaluated in the same manner. The results are shown in Table 3.

From Table 3, it can be confirmed that the same tendency is observed even when the amount of V ₂ O ₅ in the dielectric layer paste is 0.1 mol. In Example 3, it can be confirmed that particularly good results are obtained when E _V / D _V ≧ 5.

Example 4
V ₂ O ₅ of the dielectric layer paste, and V ₂ O ₅ amount to be contained in the internal electrode layer paste, except that the amount shown in Table 4, in the same manner as in Example 1, capacitor samples It produced and evaluated similarly.
That is, in this example, the amount of V ₂ O ₅ in the dielectric layer paste was 0.15 mol, and the internal electrode layer paste was not added with V ₂ O ₅ (sample number 31), the internal A sample (sample number 32) in which the amount of V ₂ O ₅ in the electrode layer paste was 0.25 mol and V ₂ O ₅ was not added to the dielectric layer paste was prepared and evaluated. . The results are shown in Table 4.

From Table 4, in Sample No. 31, the amount of V ₂ O ₅ in the dielectric layer paste was increased to 0.15 mol, and as a result, the accelerated lifetime of insulation resistance was improved, but the relative dielectric constant was low. It became the result. Furthermore, the insulation resistance at high temperature was also lowered.

In Sample No. 32 in which V ₂ O ₅ was not added to the dielectric layer paste, the accelerated life of the insulation resistance was insufficient. In addition, as shown in the graph of FIG. 2, this sample number 32 results in a large variation in the failure time between samples when evaluating the accelerated life of the insulation resistance, resulting in poor reliability. As a result. FIG. 2 is a graph showing the failure time of each evaluation sample when evaluating the accelerated life of the insulation resistance of Sample No. 2 of Example 1 and Sample No. 32 of this example, and the horizontal axis represents the failure time. The vertical axis is plotted as a natural logarithm of the reliability function. Here, as the plots are arranged in a form closer to the vertical direction (that is, when the failure times in the plots are substantially the same), the characteristic variation between the samples is smaller.

FIG. 1 is a cross-sectional view of a multilayer ceramic capacitor according to an embodiment of the present invention. FIG. 2 is a graph showing the failure time of each evaluation sample at the time of evaluating the accelerated life of the insulation resistance of the multilayer ceramic capacitor according to the example and the comparative example of the present invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Multilayer ceramic capacitor 10 ... Capacitor element main body 2 ... Dielectric layer 3 ... Internal electrode layer 4 ... External electrode

Claims (3)

A method of manufacturing a laminated electronic component in which internal electrode layers and dielectric layers are alternately laminated,
Using the internal electrode layer paste and the dielectric layer paste, a green chip is obtained in which a green sheet that becomes the dielectric layer after firing and an electrode paste layer that becomes the internal electrode layer after firing are alternately laminated. Process,
Firing the green chip,
The internal electrode layer paste contains a conductor material, barium titanate, a V oxide and / or a compound that becomes a V oxide after firing,
In the internal electrode layer paste, the ratio of the oxide of V and / or the compound that becomes an oxide of V after firing is 0.2 mol or more in terms of V ₂ O _{5 with} respect to 100 mol of the barium titanate. And
The dielectric layer paste contains barium titanate and a V oxide and / or a compound that becomes a V oxide after firing,
In the dielectric layer paste, the ratio of the oxide of V and / or the compound that becomes an oxide of V after firing is more than 0 mol in terms of V ₂ O _{5 with} respect to 100 mol of the barium titanate, A method for producing a multilayer electronic component having a content of 0.1 mol or less. The ratio of the oxide and / or become oxides of V after firing compound of V with respect to the 100 mol of barium titanate in the internal electrode layer paste, and E _V moles,
The ratio of the oxide and / or become oxides of V after firing compound of V with respect to the 100 mol of barium titanate in the dielectric layer paste, the case of the D _V moles,
The relationship between _{E V} and _{D V is} stacked method of manufacturing an electronic component according to claim 1 which is E _V / _D V ≧ 5.   3. The stacked type according to claim 1, wherein a ratio of the oxide of V and / or a compound which becomes an oxide of V after firing to 100 mol of the barium titanate in the internal electrode layer paste is less than 1 mol. Manufacturing method of electronic components.

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