JP4807161B2 - Multilayer ceramic electronic component and manufacturing method thereof - Google Patents

Description

  The present invention relates to a multilayer ceramic electronic component and a manufacturing method thereof, and more particularly to a multilayer ceramic electronic component including a via conductor and a manufacturing method thereof.

  A multilayer ceramic electronic component includes a multilayer body having a multilayer structure including a plurality of multilayered ceramic layers. In the laminated body, an internal conductor film is usually formed along a specific interface between a plurality of ceramic layers, and an external conductor film is formed on the outer surface. The laminated body may also be provided with a via conductor so as to penetrate a specific ceramic layer in the thickness direction. Via conductors electrically connect a plurality of internal conductor films formed along different interfaces between ceramic layers, electrically connect internal conductor films and external conductor films to each other, The external conductor films respectively formed on the opposing main surfaces are electrically connected.

  A multilayer ceramic electronic component including the above-described via conductor is generally manufactured as follows. A conductive paste containing metal powder is prepared. On the other hand, a plurality of ceramic green sheets to be a ceramic layer are prepared, and a via hole is provided in a specific ceramic green sheet so as to penetrate the ceramic green sheet in the thickness direction. The via hole is filled with the above-described conductive paste, and a plurality of ceramic green sheets are laminated to obtain a raw laminate, and the raw laminate is fired to obtain a multilayer ceramic electronic. Parts are obtained.

  However, in the multilayer ceramic electronic component obtained as described above, the via conductor is caused by the difference in the degree of dimensional change during firing of the ceramic powder in the ceramic green sheet and the metal powder in the conductive paste. In some cases, a structural defect such as a gap is formed between the inner surface of the via hole and the inner peripheral surface of the via hole. The occurrence of such a structural defect causes an increase in electrical resistance or disconnection of the wiring conductor including the via conductor.

  In order to solve the above-described problem, for example, Japanese Patent Laid-Open No. 3-212993 (Patent Document 1) proposes that a conductive paste used for forming a via conductor contains ceramic powder. According to this, sintering of the metal powder in the conductive paste is suppressed, and it is possible to make it difficult to cause the structural defects as described above.

However, the inclusion of ceramic powder in the conductive paste causes another problem. That is, since ceramic powder is usually an electrical insulator, it increases the electrical resistance of the via conductor. Therefore, in applications where a relatively large current flows through the via conductor, the temperature rise of the product due to the heat generated from the via conductor cannot be ignored. For example, multilayer ceramics having via conductors such as multilayer ceramic substrates, multilayer ceramic inductors, multilayer ceramic capacitors, etc. There is a problem in expanding the use of electronic components.
Japanese Patent Laid-Open No. 3-212993

  Accordingly, an object of the present invention is to provide a multilayer ceramic electronic component that can solve the above-described problems and a method for manufacturing the same.

  The present invention provides a laminate having a laminated structure composed of a plurality of laminated ceramic layers, an internal conductor film formed on a specific ceramic layer, and a specific ceramic layer penetrating in the thickness direction. In order to solve the above technical problem, the following configuration is provided, which is directed to a multilayer ceramic electronic component including a via conductor that is in contact with a specific internal conductor film. Yes.

  That is, in the multilayer ceramic electronic component according to the present invention, the via conductor contains metal powder and ceramic powder, but the ceramic powder in the via conductor is from the center of the via conductor to the outer peripheral side in the radial direction of the via conductor. It is characterized by the existence of a concentration gradient that decreases toward the bottom.

  In the multilayer ceramic electronic component according to the present invention, preferably, a region where no ceramic powder is present is formed on the outer periphery of the via conductor.

  The ceramic constituting the ceramic powder in the via conductor is preferably of the same material system as the ceramic constituting the ceramic layer.

  The via conductor is preferably in contact with the specific inner conductor film on the outer peripheral surface thereof, but may be in contact with the specific inner conductor film on the end surface.

  The present invention is also directed to a method of manufacturing the multilayer ceramic electronic component as described above.

  A method for manufacturing a multilayer ceramic electronic component according to the present invention includes a step of preparing a plurality of ceramic green sheets, a step of forming an internal conductor film on a specific ceramic green sheet, and a stack of the plurality of ceramic green sheets. In order to solve the technical problem described above, a process for obtaining a raw laminate and a process for firing the raw laminate are provided.

  That is, the first conductive paste containing the metal powder and the ceramic powder, and containing the metal powder and containing the ceramic powder in an amount smaller than the ceramic powder in the first conductive paste or containing the ceramic powder A second conductive paste is prepared. On the other hand, a via hole is provided so as to penetrate a specific ceramic green sheet in the thickness direction.

  Then, a step of injecting the second conductive paste into the via hole and thereby attaching the second conductive paste along the inner peripheral surface of the via hole, and the second conductive paste adhered to the inner peripheral surface And filling the via hole with the first conductive paste.

  In the method for manufacturing a multilayer ceramic electronic component according to the present invention, when providing a via hole penetrating the multilayer body, the step of providing the via hole may be performed before the step of obtaining the raw multilayer body, It is carried out after the step of obtaining a raw laminate. And when the process of providing a via hole is implemented after the process of obtaining a raw laminated body, it is preferable that a via hole is provided so that a specific internal conductor film may be penetrated.

  In addition, the step of attaching the second conductive paste along the inner peripheral surface of the via hole is performed by injecting the second conductive paste into the via hole and then leaving only the portion attached to the inner peripheral surface of the via hole. It is preferable to include a step of removing the second conductive paste from the via hole. In this case, it is preferable that the second conductive paste has a viscosity lower than that of the first conductive paste.

  According to this invention, since at least the first conductive paste located at the center of the via hole contains the ceramic powder in the firing step, at least shrinkage due to sintering of the metal powder in the first conductive paste is caused. In addition to being suppressed, structural defects such as a gap between the via conductor and the inner peripheral surface of the via hole are less likely to be caused, and the second conductive paste positioned along the inner peripheral surface of the via hole is ceramic powder. Therefore, it is possible to reduce the contact resistance between the outer periphery of the via conductor and the internal conductor film in contact with the via conductor after firing, thereby improving the reliability of the multilayer ceramic electronic component. Can do.

  Further, in the multilayer ceramic electronic component, the ceramic powder in the via conductor exists with a concentration gradient that decreases from the center of the via conductor toward the outer peripheral side in the radial direction of the via conductor. In the outer peripheral portion, a relatively good electrical conduction state is ensured.

  For these reasons, not only does the wiring conductor including the via conductor and the internal conductor film hardly break, but also the electrical resistance of the wiring conductor including the via conductor and the internal conductor can be reduced. Therefore, the present invention can be directed without problems to the application of a relatively large current to the via conductor and the internal conductor, and the application of the multilayer ceramic electronic component can be expanded.

  In addition, when the multilayer ceramic electronic component is directed to an application in which a high-frequency signal flows through the via conductor, the current concentrates on the outer peripheral side of the via conductor due to the skin effect. Since electrical resistance can be lowered, good transmission characteristics can be obtained.

  In the multilayer ceramic electronic component according to the present invention, if there is a region where the ceramic powder is not present on the outer peripheral portion of the via conductor, the electrical resistance of the via conductor itself can be lowered more reliably and the inner conductor film The contact resistance can be lowered more reliably.

  When the ceramic constituting the ceramic powder contained in the via conductor is of the same material system as the ceramic constituting the ceramic layer, the ceramic powder in the via conductor does not adversely affect the characteristics of the ceramic layer, and A good bonding state can be obtained between the via conductor and the ceramic layer.

  If the via conductor is brought into contact with a specific internal conductor film on the outer peripheral surface thereof, the contact resistance with the internal conductor film can be lowered on all the surfaces of the via conductor in contact with the internal conductor film.

  In the method for manufacturing a multilayer ceramic electronic component according to the present invention, after obtaining the raw multilayer body, the via hole is provided so as to penetrate the specific internal conductor film while performing the step of providing the via hole. A via hole with high alignment accuracy can be efficiently formed, a highly reliable via conductor can be formed, and a structure in which the via conductor is in contact with the inner conductor film on the outer peripheral surface thereof. Can be easily obtained.

  In the method for manufacturing a multilayer ceramic electronic component according to the present invention, when the second conductive paste is adhered along the inner peripheral surface of the via hole, the second conductive paste is injected into the via hole, and then the inner periphery of the via hole. If the excess second conductive paste is removed from the via hole while leaving only the portion adhering to the surface, the amount of the second conductive paste is attached from the beginning along the inner peripheral surface of the via hole. Compared with the case where the second conductive paste is applied while performing the general control, it is possible to obtain a state in which the second conductive paste is efficiently attached along the inner peripheral surface of the via hole. In this case, if a second conductive paste having a viscosity lower than that of the first conductive paste is used, it becomes easier to remove the excess second conductive paste from the via hole.

  FIG. 1 is a view for explaining an embodiment of the present invention, two ceramic layers 1a that are to be adjacent to each other, or two ceramic green sheets 1a to be provided in a multilayer ceramic electronic component, and those Each part of the inner conductor film 2 located between them is enlarged and shown in a sectional view. In FIG. 1, the two ceramic layers 1 or the two ceramic green sheets 1 a are simply illustrated in order to facilitate the description including the inner conductor film 2 positioned between them. is there.

  In FIG. 1, (5) shows a ceramic layer 1 provided in a multilayer ceramic electronic component, and (1) to (4) show several steps performed to obtain a multilayer ceramic electronic component. Are shown sequentially.

  First, as shown in FIG. 1A, a ceramic green sheet 1a to be the ceramic layer 1 is prepared, and then an internal conductor film 2 is formed on the specific ceramic green sheet 1a by printing a conductive paste. . Next, a plurality of ceramic green sheets including the two ceramic green sheets 1a shown in the figure are laminated and pressed in the laminating direction, thereby obtaining a raw laminated body 10a.

  Next, referring also to FIG. 1 (1), via hole 3 is provided in raw laminate 10a so as to penetrate ceramic green sheet 1a in the thickness direction. For example, drilling, punching, or laser is applied to the formation of the via hole 3. The via hole 3 is provided so as to penetrate the internal conductor film 2, and the cut surface of the internal conductor film 2 is exposed on the inner peripheral surface of the via hole 3.

  On the other hand, the first conductive paste containing the metal powder and the ceramic powder, and containing the metal powder and containing the ceramic powder in an amount smaller than the ceramic powder in the first conductive paste or containing the ceramic powder A second conductive paste is prepared.

  Here, the content of the ceramic powder in the first conductive paste is preferably 10 to 20% by weight. This is because if it is less than 10% by weight, sintering shrinkage may not be sufficiently suppressed in the firing step described later, and if it exceeds 20% by weight, the electrical resistance may become too high. The content of the ceramic powder in the second conductive paste is preferably 0 to 15% by weight. If it exceeds 15% by weight, it may not be preferable from the viewpoint of electrical resistance. In order to obtain the lowest possible electrical resistance, it is most preferable not to contain ceramic powder.

As the ceramic constituting the ceramic powder contained in the first and second conductive pastes, the following can be used. When a metal having a relatively high melting point, such as Ni or Ag—Pd, is used as the metal constituting the metal powder contained in the first and second conductive pastes, BaTiO ₃ , CaTiO ₃ , SrTiO ₃ , CaZrO _A dielectric ceramic whose sintering temperature is relatively high, mainly composed of ₃ or the like, can be used. In addition, you may use what added subcomponents, such as a Mn compound, Fe compound, Cr compound, Co compound, Ni compound, to these main components. On the other hand, when a metal having a relatively low melting point such as Cu or Ag is used as the metal constituting the metal powder contained in the conductive paste, a glass ceramic in which Al ₂ O ₃ and borosilicate glass are mixed is used. , Ba—Al—Si—O-based ceramics or the like can be used.

  The ceramic constituting the ceramic powder in the conductive paste is the same material as the ceramic constituting the ceramic layer 1, that is, the ceramic component contained in the ceramic green sheet 1a, in other words, having the same main component. It is preferred that it is the same ceramic. This is because the ceramic powder in the conductive paste not only does not adversely affect the characteristics of the ceramic layer 1 after firing, but also provides good bondability with the ceramic layer 1 after firing. . In addition, in this specification, a main component means the component exceeding 50 weight% of all the components.

  The average particle size of the ceramic powder in the first and second conductive pastes is preferably selected in the range of 0.1 to 0.5 μm. The average particle size of the ceramic powder is preferably smaller than the thickness of the internal conductor film 2.

  Next, as shown in FIG. 1 (2), the second conductive paste 4 is injected into the via hole 3 provided in the ceramic green sheet 1a. Subsequently, as shown in FIG. The conductive paste 4 is attached along the inner peripheral surface of the via hole 3. For injection of the second conductive paste 4, for example, press-fitting, squeegee or the like is applied. In FIG. 1 (2) and FIGS. 1 (3) and (4) described later, the form or behavior of the second conductive paste 4 is adapted to the via hole 3 penetrating the two ceramic green sheets 1a. It should be pointed out that this is for illustration purposes only.

  As shown in FIG. 1 (3), in order to efficiently obtain a state in which the second conductive paste 4 adheres along the inner peripheral surface of the via hole 3, the second conductive paste 4 is applied to the via hole 3. After the injection, it is preferable to remove the excess second conductive paste 4 from the via hole 3 while leaving only the portion attached to the inner peripheral surface of the via hole 3.

  In this case, in order to make it possible to easily remove the excess second conductive paste 4 described above, the viscosity of the second conductive paste 4 is lower than the viscosity of the first conductive paste, More specifically, it is preferable to select a viscosity range of 10 to 20 Pa · s (a value of 20 rpm in a Brookfield viscometer). Here, the preferable range of the viscosity is selected to be 10 to 20 Pa · s. If the viscosity is less than 10 Pa · s, the second conductive paste 4 may not sufficiently adhere to the inner peripheral surface of the via hole 3. On the other hand, if it exceeds 20 Pa · s, the excess second conductive paste 4 is difficult to escape from the via hole 3, and there may be a case where a space 5 for filling the first conductive paste described later cannot be sufficiently formed. Because.

  If the viscosity of the second conductive paste 4 is lowered as described above, depending on the diameter of the via hole 3, all of the injected second conductive paste 4 cannot stay in the via hole 3, A part of the leakage naturally leaks from the via hole 3, and as a result, as shown in FIG. 1 (3), it is possible to realize a state of adhering along the inner peripheral surface of the via hole 3.

  If the state of FIG. 1 (2) cannot be obtained smoothly from the state of FIG. 1 (2) due to the relatively high viscosity of the second conductive paste 4, etc., compressed air The excess second conductive paste 4 may be forcibly removed by blowing the resin toward the via hole 3 or contacting a blotting paper.

  Next, the second conductive paste 4 is dried. Although this drying may be performed at room temperature or under heating, it is preferably at a temperature not higher than the glass transition point (Tg) of the resin contained in the ceramic green sheet 1a.

  Next, as shown in FIG. 1 (4), the first conductive paste 6 is filled in the via hole 3 in which the second conductive paste 4 adheres to the inner peripheral surface. For example, press-fitting or squeegee is applied to the filling of the first conductive paste 6.

  The viscosity of the first conductive paste 6 is preferably selected in the range of 100 to 200 Pa · s. If it is less than 100 Pa · s, the first conductive paste 6 is less likely to remain inside the via hole 3, and the density of the via conductor obtained by firing, which will be described later, may be reduced. On the other hand, if it exceeds 200 Pa · s, depending on the length of the via hole 3 in the axial direction, that is, in this embodiment, depending on the thickness of the raw laminated body 10 a, the first conductive paste 6 is sufficient in the via hole 3. May not be filled. In order to smoothly fill the inside of the via hole 3 with the first conductive paste 6, a negative pressure is applied from one opening side of the via hole 3 by vacuum suction or the like, while the first conductive paste 6 is applied from the other opening side. A method of introducing the conductive paste 6 is effective.

  Next, the first conductive paste 6 in the via hole 3 is dried. The preferable conditions for this drying are the same as in the case of the second conductive paste 4 described above.

  The volume ratio of the first and second conductive pastes 6 and 4 in the via hole 3 is smaller than the volume of the second conductive paste 4 than the volume of the second conductive paste 4. It is preferable.

  Next, the raw laminate 10a is fired. For this firing, for example, a temperature of 900 to 1300 ° C. is applied. When a low melting point metal such as Cu is used as the metal constituting the metal powder contained in the conductive pastes 4 and 6, a firing temperature of 1000 ° C. or less is applied.

  As a result of the firing described above, a sintered laminate 10 is obtained as shown in FIG. In this laminate 10, the ceramic green sheet 1 a is sintered to become the ceramic layer 1, the internal conductor film 2 is sintered, and the conductive pastes 4 and 6 are also sintered to become the via conductor 7. . The via conductor 7 has an outer peripheral portion 8 and a central portion 9 although there is no clear boundary between them. The outer peripheral portion 8 is derived from the second conductive paste 4, and the central portion 9 is derived from the first conductive paste 6. Therefore, the content of the ceramic powder is larger in the central portion 9 than in the outer peripheral portion 8, and as a result, the ceramic powder in the via conductor 7 is located on the outer peripheral side from the center of the via conductor 7 in the radial direction of the via conductor 7. It exists with a concentration gradient that decreases toward.

  Due to the presence of the ceramic powder as described above, a relatively good electrical conduction state can be obtained in the outer peripheral portion 8 of the via conductor 7, so that the contact resistance with the inner conductor film 2 in contact with the outer peripheral surface of the via conductor 7 is reduced. can do. Further, the skin effect makes it easy for high-frequency signals concentrated on the outer peripheral portion 8 to flow, and good transmission characteristics can be obtained. In particular, when the second conductive paste 4 does not contain a ceramic powder, the above-described effect appears remarkably.

  In addition, at least the ceramic powder present in the first conductive paste 6 suppresses the sintering of the metal powder inside the via conductor 7, and it is difficult for a gap to be formed between the via conductor 7 and the ceramic layer 1.

  The diameter of the via conductor 7 is preferably selected in the range of 50 to 150 μm. When the thickness is less than 50 μm, it may be difficult to introduce the conductive pastes 4 and 6 into the via hole 3. Further, the contact area between the via conductor 7 and the internal conductor film 2 is reduced, and a good electrical conduction state may not be obtained. On the other hand, when the diameter of the via conductor 7 exceeds 150 μm, the moisture resistance may be lowered.

  The length in the axial direction of the via conductor 7 is not particularly limited, and can take various lengths depending on the application. In the case where the via conductor 7 is provided so as to penetrate the entire thickness of the multilayer body 10 provided in the multilayer ceramic electronic component, the length of the via conductor 7 is in a practical range of 100 μm to 1 mm.

  In the above-described embodiment, two types of conductive pastes were used as the conductive paste, such as the first and second conductive pastes 6 and 4 having different ceramic powder contents. Three or more kinds of conductive pastes having different amounts in three or more stages may be used, and the concentration distribution of the ceramic powder may be given in three or more stages.

  FIG. 2 is a cross-sectional view showing a multilayer ceramic capacitor 11 as an example of a multilayer ceramic electronic component to which the present invention can be applied. This multilayer ceramic capacitor 11 has been proposed for the purpose of reducing the equivalent series inductance.

  The multilayer ceramic capacitor 11 includes a multilayer body 12. The laminated body 12 has a laminated structure composed of a plurality of laminated ceramic layers 13.

  Inside the multilayer body 12, a plurality of first and second internal electrodes 14 and 15 are formed as internal conductor films along specific interfaces between the plurality of ceramic layers 13. The first and second internal electrodes 14 and 15 are alternately arranged in the stacking direction.

  The multilayer body 12 is provided with a plurality of first and second via conductors 16 and 17, respectively. The first internal electrode 14 is electrically connected to the first via conductor 16 while being electrically insulated from the second via conductor 17. The second internal electrode 15 is electrically connected to the second via conductor 17 while being electrically insulated from the first via conductor 16.

  In the connection between the first internal electrode 14 and the first via conductor 16, the outer peripheral surface of the first via conductor 16 is in contact with the first internal electrode 14. Further, in connection between the second internal electrode 15 and the second via conductor 17, the outer peripheral surface of the second via conductor 17 is in contact with the second internal electrode 15.

  The first and second via conductors 16 and 17 are provided alternately so as to penetrate the multilayer body 12 in the thickness direction, that is, to penetrate all the ceramic layers 13 in the thickness direction. On both main surfaces of the body 12, a first external electrode 18 electrically connected to the first via conductor 16 and a second external conductor 19 electrically connected to the second via conductor 17 are provided. Is formed.

  In such a multilayer ceramic capacitor 11, the first and second via conductors 16 and 17 are formed by a method substantially similar to the case of the via conductor 7 shown in FIG. Accordingly, although not shown in FIG. 2, the via conductors 16 and 17 have substantially the same structure as the via conductor 7 shown in FIG. With respect to the radial direction, there exists a concentration gradient that decreases from the center of the via conductors 16 and 17 toward the outer peripheral side.

  When forming the via conductors 16 and 17, a plurality of ceramic green sheets having via holes are stacked so that the via holes are aligned on the same axis and communicate with each other, and the aligned via holes are filled with a conductive paste. As described with reference to FIG. 1 or the first method, a plurality of ceramic green sheets are laminated, and via holes penetrating all the ceramic green sheets are formed at once, and the via holes are electrically conductive. A second method of filling the paste can be employed. Of these methods, the second method, in other words, the method of providing a via hole after obtaining a raw laminate, does not require alignment of each via hole of a plurality of ceramic green sheets, and has high accuracy. Via conductors 16 and 17 can be formed.

  FIG. 3 is a cross-sectional view showing a multilayer ceramic substrate 21 as another example of a multilayer ceramic electronic component to which the present invention can be applied.

  The multilayer ceramic substrate 21 includes a laminated body 22. The laminated body 22 has a laminated structure composed of a plurality of laminated ceramic layers 23.

  Several internal conductor films 24 are formed along the interface between the plurality of ceramic layers 23 inside the multilayer body 22. Further, several via conductors 25 electrically connected to the specific internal conductor film 24 are provided so as to penetrate the specific ceramic layer 23 in the thickness direction. In addition, several external conductor films 26 are formed on the outer surface of the multilayer body 22.

  In such a multilayer ceramic substrate 21, the via conductor 25 has substantially the same structure as the via conductor 7 shown in FIG. 1 (5), and the ceramic powder is related to the radial direction of the via conductor 25. There exists a concentration gradient that decreases from the center of the via conductor 25 toward the outer peripheral side.

  In the multilayer ceramic substrate 21, the via conductor 25 is in contact with a specific internal conductor film 24 or a specific external conductor film 26 at its end face. Even in this case, the outer peripheral portion of the via conductor 25 having a relatively low electric resistance can be brought into contact with the inner conductor film 24 or the outer conductor film 26.

  When the position of the via conductor 25 is different for each ceramic layer 23 as in the multilayer ceramic substrate 21 shown in FIG. 3, via holes are respectively formed in the plurality of ceramic green sheets, and A method of laminating a plurality of ceramic green sheets after filling with a conductive paste according to substantially the same steps as the steps shown in (2) to (4) can be adopted.

  Next, experimental examples carried out to confirm the effects of the present invention will be described. In this experimental example, a multilayer ceramic capacitor 11 having a structure as shown in FIG. 2 was produced as a sample.

  First, samples according to examples within the scope of the present invention were produced under the following conditions.

The dimension of the multilayer body 12 provided in the multilayer ceramic capacitor 11 as a sample was 3 mm × 3 mm × 0.85 mm. The ceramic layer 13 is made of ceramic mainly composed of BaTiO ₃ and has a thickness of 3 μm. The diameter of each of the via conductors 16 and 17 was 100 μm. Ni was used as the conductive component of the internal electrodes 14 and 15.

  Further, for forming the via conductors 16 and 17, a second conductive paste containing Ni powder, isopropyl alcohol and polyvinyl butyral was used. That is, the composition does not contain ceramic powder. The viscosity of the second conductive paste was 10 Pa · s, and a temperature of 60 ° C. was applied in drying after pouring into the via hole.

On the other hand, as the first conductive paste, a paste containing Ni powder, ceramic powder, isopropyl alcohol and polyvinyl butyral was used. Here, as the ceramic powder, a ceramic powder mainly composed of BaTiO ₃ having an average particle diameter of 0.2 μm was used, and the content in the first conductive paste was 10% by weight. In addition, the viscosity of the first conductive paste was 150 Pa · s, and a temperature of 60 ° C. was applied in the drying step after filling the via holes.

  Further, in the step of firing the raw laminate for obtaining the laminate 12, a temperature of 1250 ° C. was applied in a neutral atmosphere. Further, Cu was used as the conductive component of the external electrodes 18 and 19, and in order to form this by baking, a temperature of 800 ° C. was applied in a reducing atmosphere.

  On the other hand, as a sample according to Comparative Example 1 outside the scope of the present invention, a via hole filled with only the second conductive paste was prepared in order to form the via conductors 16 and 17. Moreover, in order to form the via conductors 16 and 17 as a sample according to Comparative Example 2, a via hole filled with only the first conductive paste was produced. For all of Comparative Examples 1 and 2, the other conditions were the same as in the example.

  When these Examples and Comparative Examples 1 and 2 are compared, when a DC voltage is applied between a pair of external electrodes 18 or 19 connected to an arbitrary via conductor 16 or 17, and a specific resistance is measured, Comparative Example 2 is obtained. The specific resistance was higher than that of the example and the comparative example 1.

  Moreover, when the cross section of the arbitrary via conductor 16 or 17 was observed by SEM, in Example and Comparative Example 2, there was no gap exceeding 1 μm at the boundary with the ceramic layer 13, whereas in Comparative Example 1 It was confirmed that such a gap exists.

It is a figure for describing one embodiment of the present invention, and is provided in a multilayer ceramic electronic component, two adjacent ceramic layers 1 or two ceramic green sheets 1a to be ceramic layers 1 and a position between them FIG. 2 is an enlarged cross-sectional view of each part of the inner conductor film 2 and sequentially shows several steps performed in the method for manufacturing a multilayer ceramic electronic component. It is sectional drawing which shows the multilayer ceramic capacitor 11 as an example of the multilayer ceramic electronic component with which this invention can be applied. It is sectional drawing which shows the multilayer ceramic substrate 21 as another example of the multilayer ceramic electronic component with which this invention can be applied.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1,13,23 Ceramic layer 1a Ceramic green sheet 2 Internal conductor film 3 Via hole 4 2nd electroconductive paste 6 1st electroconductive paste 7, 16, 17, 25 Via conductor 8 Outer peripheral part 9 Center part 10,12, 22 Laminated body 10a Raw laminated body 11 Multilayer ceramic capacitor 21 Multilayer ceramic substrate

Claims (9)

A laminated body having a laminated structure comprising a plurality of laminated ceramic layers;
An inner conductor film formed on the specific ceramic layer;
A via conductor provided so as to penetrate the specific ceramic layer in the thickness direction and in contact with the specific internal conductor film,
The via conductor contains a metal powder and a ceramic powder,
The ceramic powder in the via conductor is present with a concentration gradient that decreases from the center of the via conductor toward the outer peripheral side with respect to the radial direction of the via conductor.
Multilayer ceramic electronic components.   The multilayer ceramic electronic component according to claim 1, wherein there is a region where the ceramic powder is not present on an outer peripheral portion of the via conductor.   The multilayer ceramic electronic component according to claim 1, wherein the ceramic constituting the ceramic powder is of the same material system as the ceramic constituting the ceramic layer.   4. The multilayer ceramic electronic component according to claim 1, wherein the via conductor is in contact with the specific inner conductor film on an outer peripheral surface thereof. 5.   5. The multilayer ceramic electronic component according to claim 1, wherein the via conductor is in contact with the specific inner conductor film at an end surface thereof. 6. A step of preparing a plurality of ceramic green sheets, a step of forming an internal conductor film on the specific ceramic green sheet, a step of obtaining a raw laminate by laminating the plurality of ceramic green sheets, A method for producing a multilayer ceramic electronic component comprising a step of firing a raw laminate,
First conductive paste containing metal powder and ceramic powder, and containing metal powder and containing ceramic powder in an amount less than ceramic powder in first conductive paste or containing ceramic powder Not preparing each of the second conductive pastes;
Providing a via hole so as to penetrate the specific ceramic green sheet in the thickness direction;
Injecting the second conductive paste into the via hole, thereby attaching the second conductive paste along the inner peripheral surface of the via hole;
Filling the via hole with the second conductive paste adhering to the inner peripheral surface with the first conductive paste;
When in the state of the raw laminate, at least the second conductive paste is in contact with the specific inner conductor film,
Manufacturing method of multilayer ceramic electronic component.   The multilayer ceramic electronic component according to claim 6, wherein the step of providing the via hole is performed after the step of obtaining the raw multilayer body, and the via hole is provided to penetrate the specific internal conductor film. Production method.   The step of attaching the second conductive paste along the inner peripheral surface of the via hole leaves only the portion attached to the inner peripheral surface of the via hole after injecting the second conductive paste into the via hole. The method for manufacturing a multilayer ceramic electronic component according to claim 6, further comprising a step of removing excess second conductive paste from the via hole.   The method of manufacturing a multilayer ceramic electronic component according to claim 8, wherein the second conductive paste has a viscosity lower than that of the first conductive paste.

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