JP4463045B2 - Ceramic electronic components and capacitors - Google Patents

Description

  The present invention relates to a ceramic electronic component and a capacitor.

  A typical ceramic electronic component will be described using a ceramic capacitor.

  FIG. 5 is a cross-sectional view showing a conventional ceramic capacitor.

  In the figure, a ceramic capacitor 30 includes internal electrodes (wiring conductors) 33 and 34 interposed between adjacent dielectric layers 32 in a laminated body 31 in which a plurality of dielectric layers (ceramic layers) 32 are laminated. External electrodes (external electrode terminals) 35 and 36 that are electrically connected to end portions of the internal electrodes 33 and 34 are formed on the side surfaces of the multilayer body 31, and one end of each of the external electrodes 35 and 36 is connected to the four layers of the multilayer body 31. It extends to the main surface.

According to the ceramic capacitor 10, the external electrodes 35 and 36 contain a metal component and a glass component. At the time of baking, the glass components gather at the interfaces between the metal components of the external electrodes 35 and 36 and the side surfaces and the four main surfaces of the multilayer body 31, so that the external electrodes 35 and 36 and the multilayer body 31 are electrically and mechanically (For example, refer to Patent Document 1).
JP 2002-270457 A

  However, according to the ceramic capacitor 30, the portion formed on the side surface of the multilayer body 31 among the external electrodes 35 and 36 is firmly connected to the internal electrodes 33 and 34 by a metal-metal bond. The portions formed on the four main surfaces of the body 31 have a weak mechanical connection strength with the laminated body 31, and as a result, as shown in FIG. It was.

  The present invention has been devised in view of the above-described problems, and an object thereof is to provide a ceramic electronic component and a capacitor that can effectively prevent peeling of external electrode terminals by a simple and inexpensive method. It is in.

  According to the present invention, a wiring conductor is disposed on and / or inside a laminated body in which a plurality of ceramic layers are laminated, and an external electrode terminal electrically connected to the wiring conductor is provided on a main surface of the laminated body. In the formed ceramic electronic component, a dummy wiring is embedded in the multilayer body with a ceramic layer between the external electrode terminal and the dummy wiring and the external electrode terminal. It is characterized by being electrically and mechanically connected through one or two metal particles present in the ceramic layer between them.

  The mechanical connection via the metal particles is performed by sintering the metal particles and the metal component in the dummy wiring, and sintering the metal particles and the metal component in the external electrode terminal. It is characterized by this.

  Further, the particle size A of the metal particles present in the ceramic layer is set to 100% to 200% with respect to the thickness B of the ceramic layer located between the dummy wiring and the extended portion of the external electrode. It is characterized by this.

  Still further, an internal electrode is interposed between adjacent dielectric layers in a laminated body in which a plurality of dielectric layers are laminated, and is electrically connected to an end portion of the internal electrode on a side surface of the laminated body. In a capacitor in which an external electrode is formed and one end of the external electrode extends to the main surface of the multilayer body, a single-layer dielectric is formed inside the multilayer body and between the extended portion of the external electrodes. The dummy electrode is embedded with the layer being separated, and the dummy electrode and the extended portion of the external electrode are electrically / mechanically interposed via one or two metal particles present in the dielectric layer between the two electrodes. It is characterized by having been connected.

  Furthermore, the mechanical connection through the metal particles is made by sintering the metal particles and the metal component in the dummy electrode, and sintering the metal particles and the metal component in the external electrode. It is characterized by this.

  The particle size A of the metal particles present in the dielectric layer is set to 100% to 200% with respect to the thickness B of the dielectric layer located between the dummy electrode and the extended portion of the external electrode. It is characterized by that.

  According to the present invention, the dummy wiring is embedded in the multilayer body with a single ceramic layer between the external electrode terminals, and the dummy wiring and the external electrode terminals exist in the ceramic layer between them. It is electrically and mechanically connected through one or two metal particles.

  That is, since the external electrode terminal is connected to the metal particle embedded in the laminate by a strong metal-metal bond on the main surface of the laminate, the mechanical connection strength between the external electrode terminal and the laminate main surface is increased. And the peeling of the external electrode terminals can be prevented.

  Further, since the metal particles are connected to the dummy wiring, the metal particles are securely fixed in one ceramic layer, and this also effectively prevents the external electrode terminal from being peeled off. Further, it is possible to prevent peeling between the dummy wiring and the ceramic layer between the dummy wiring and the external electrode terminal.

  Furthermore, since one or two metal particles are present in the ceramic layer, the entire metal particle has an indefinite shape and does not fall out of the ceramic layer due to external impact or the like.

  Furthermore, since the mechanical connection through the metal particles is made by sintering the metal particles and the metal component in the dummy wiring, and by sintering the metal particles and the metal component in the external electrode terminal, The mechanical connection can be realized without changing the production line, and the metal particles, the dummy wiring, and the external electrode terminal are integrated. This also effectively prevents the external electrode terminal from being peeled off.

  Furthermore, the particle size A of the metal particles present in the ceramic layer is set to 100% to 200% with respect to the thickness B of the ceramic layer located between the dummy wiring and the extended portion of the external electrode. desirable. That is, since the average particle diameter A of the metal particles is 100% or more with respect to the thickness B of the ceramic layer, the metal particles penetrate the ceramic layer, and the dummy wiring and the external electrode terminal can be reliably connected. On the other hand, since the average particle diameter A of the metal particles is 200% or less with respect to the thickness B of the ceramic layer, the dummy wiring can be formed with high precision by screen printing or the like at the time of manufacture, and the ceramic that becomes the laminate When pressurizing and heating the layers and wiring conductors, there is no problem of a decrease in adhesion between the ceramic layers.

  For the reasons described above, the present invention interposes an internal electrode between adjacent dielectric layers in a laminated body in which a plurality of dielectric layers are laminated, and electrically connects the end of the internal electrode to the side surface of the laminated body. The capacitor is particularly suitable for a capacitor in which external electrodes to be connected are formed and one end of the external electrode is extended to the main surface of the laminate.

  Hereinafter, the present invention will be described in detail with reference to the accompanying drawings.

  1A and 1B are diagrams showing a ceramic capacitor according to an embodiment of the present invention, in which FIG. 1A is an external perspective view, and FIG. 1B is a cross-sectional view. FIG. 2 is a cross-sectional view showing a method for manufacturing the ceramic capacitor of FIG.

  In the figure, a ceramic capacitor 10 includes an internal electrode 3a, 4a interposed between adjacent dielectric layers 2 in a laminated body 1 in which a plurality of dielectric layers (ceramic layers) 2 are laminated, and a laminated body 1 External electrodes (external electrode terminals) 5, 6 electrically connected to the end portions of the internal electrodes 3 a, 4 a are formed on the side surfaces of the external electrodes 5, 6, and one ends of the external electrodes 5, 6 are extended to the four main surfaces of the laminate 1. It is left.

The dielectric layer 2 is formed to a thickness of 0.5 μm to 4 μm per layer by a dielectric material mainly composed of, for example, BaTiO ₃ , CaTiO ₃ , SrTiO _{3, and the} like. The stacked body 1 is formed by stacking, for example, 20 to 2000 layers in a direction perpendicular to the mounting surface of the capacitor 10.

  The internal electrodes 3a and 4a are formed to a thickness of, for example, 0.5 μm to 2.0 μm by using a conductive material whose main component is a metal such as Ni, Cu, Cu—Ni, or Ag—Pd.

  The external electrodes 5 and 6 are made to wrap around four main surfaces adjacent to each other from a pair of side surfaces of the laminate 1 by a conductive material mainly composed of a metal such as Ni, Cu, Cu-Ni, and Ag and a glass component. Is formed.

  What is important in the present invention is that the dummy electrode 3b, 4b is embedded in the laminated body 1 with the dielectric layer 2 of one layer between the extending portions of the external electrodes 5, 6 and the dummy electrode. 3b, 4b and the extended portions of the external electrodes 5, 6 are electrically and mechanically connected via one or two metal particles M present in the dielectric layer 2 between the electrodes. . In the figure, the internal electrodes 3a, 4a and the dummy electrodes 3b, 4b are combined to form the wiring conductors 3, 4. The dummy electrodes 3b and 4b may be the same conductive material as the internal electrodes 3a and 4a, or may be different conductive materials. The metal particles M may be the same metal as other small metal particles (hereinafter referred to as metal fine particles) m in the dummy electrodes 3b and 4b, or may be different metals. Further, in the drawing, two layers of the dummy electrodes 3b and 4b are arranged on one main surface side of the laminate 1, but any number of layers may be used as long as it is one or more layers. As the number of dummy electrodes 3b and 4b increases, the mechanical connection strength between the external electrodes 5 and 6 and the main surface of the multilayer body 1 can be increased, and peeling of the external electrodes 5 and 6 can be prevented. In the drawing, a plurality of metal particles M are embedded so as to straddle between adjacent dummy electrodes (3b-3b, 4b-4b). However, such metal particles M may not be embedded.

  Furthermore, the mechanical connection via the metal particles M is achieved by sintering the metal particles M and the metal components in the dummy electrodes 3b and 4b, and sintering the metal particles M and the metal components in the external electrodes 5 and 6. Has been made.

  The particle size A of the metal particles M present in the dielectric layer 2 is 100% of the thickness B of the dielectric layer 2 located between the extended portions of the dummy electrodes 3b and 4b and the external electrodes 5 and 6. It is set to ~ 200%. Here, the particle size A of the metal particles M can be confirmed by observing with a metal microscope after chemically etching the fracture surface of the fired laminate 1.

  Hereinafter, the manufacturing method of the ceramic capacitor 10 of this invention is demonstrated. In addition, each code | symbol in a figure shall not distinguish before and after baking.

First, an appropriate organic solvent, glass frit, organic binder, and the like are added to and mixed with a dielectric material powder mainly composed of BaTiO ₃ , CaTiO ₃ , SrTiO _3, etc. to produce a slurry ceramic slurry. A ceramic green sheet 2 to be a dielectric layer having a predetermined shape and a predetermined thickness is formed from the ceramic slurry thus obtained by a conventionally known doctor blade method or the like.

  Next, a conductive paste obtained by adding and mixing an appropriate organic solvent, an organic binder, etc. to a powder of a metal material such as Ni, Cu, Cu—Ni, Ag—Pd, etc. on the ceramic green sheet 2 is conventionally known. A predetermined pattern is applied by screen printing or the like to form conductor patterns 3 and 4 to be wiring conductors. At this time, as shown in FIG. 2A, metal particles M having a relatively large particle size are mixed in the conductor pastes 3b and 4b serving as dummy electrodes. Specifically, when the thickness of the ceramic green sheet 2 is 0.5 μm to 1 μm, the average particle size of the metal particles M having a large particle size is 0.5 μm to 2 μm, and other small metal particles (hereinafter referred to as metal fine particles). .) The average particle size of m is preferably in the range of 0.1 μm to 0.3 μm. On the other hand, when the thickness of the ceramic green sheet 2 is 1 μm to 2 μm, the average particle size of the metal particles M is in the range of 1 to 4 μm, and the average particle size of the other metal fine particles m is in the range of 0.3 μm to 0.5 μm. Is desirable. Further, when the thickness of the ceramic green sheet 2 is 2 μm to 3 μm, the average particle size of the metal particles M is desirably 2 μm to 6 μm, and the average particle size of the metal fine particles m is desirably in the range of 0.4 μm to 0.6 μm. . When the thickness of the ceramic green sheet 2 is 3 μm to 4 μm, the average particle size of the metal particles M is preferably 3 μm to 8 μm, and the average particle size of the metal fine particles m is preferably in the range of 0.5 μm to 0.1 μm. .

  Next, as shown in FIG. 2B, a predetermined number of ceramic green sheets 2 on which conductor patterns 3 and 4 are formed are stacked.

  Next, the large laminated body 11 is obtained by pressurizing and heating the laminated conductor patterns 3 and 4 and the ceramic green sheet 2. At this time, as shown in FIG. 2C, since the metal particles M are contained in the conductor patterns 3 b and 4 b serving as dummy electrodes, the metal particles M break through the ceramic green sheet 2, and the large-sized laminate 11. It is exposed on the surface or straddles the conductor pattern (3b-3b, 4b-4b) that becomes an adjacent dummy electrode. Further, the ceramic green sheet 2 to be pierced by the metal particles M is desirably softer than the other ceramic green sheets 2 or is a thermoplastic ceramic green sheet 2.

  Next, the large-sized laminated body 11 is cut | disconnected by a predetermined dimension, and the laminated body 1 of an unbaking state is obtained.

  Next, the laminated body 1 is obtained by firing the obtained unfired laminated body 1 at a temperature of 1100 ° C. to 1400 ° C., for example. At this time, one or two metal particles M embedded in the laminate 1 can be exposed to the surface of the laminate 1 by barrel polishing the laminate 1 after firing.

  Next, external electrodes 5 and 6 are formed on a pair of side surfaces of the laminate 1. That is, a conductive paste obtained by adding and mixing an appropriate glass component, an organic solvent, an organic binder, etc. to a powder of a metal material such as Ni, Cu, Cu-Ni, Ag, etc. is obtained by a conventionally known dip method, screen printing, etc. After application to the pair of side surfaces of the laminate 1, baking is performed at 700 ° C. to 900 ° C. to obtain external electrodes 5 and 6. If necessary, the surfaces of the external electrodes 5 and 6 may be covered with a metal plating layer (not shown) such as a Ni plating layer, a Sn plating layer, or a solder plating layer.

  In this way, a ceramic capacitor 10 as shown in FIG. 1 is obtained.

  Thus, according to the present invention, the dummy electrodes 3b and 4b are embedded in the multilayer body 1 with the one dielectric layer 2 between the outer electrodes 5 and 6 and the dummy electrodes 3b and 4b. Since the external electrodes 5 and 6 are electrically and mechanically connected via one or two metal particles M existing in the dielectric layer 2 between them, the external electrodes 5 and 6 are laminated. Since the main surface of the body 1 is connected to the metal particles M embedded in the multilayer body 1 by a strong metal-metal bond, the mechanical connection strength between the external electrodes 5 and 6 and the main surface of the multilayer body 1 is increased. And the separation 37 of the external electrodes 5 and 6 can be prevented.

  Further, since the metal particles M are connected to the dummy electrodes 3b and 4b, the metal particles M are securely fixed in the one dielectric layer 2, and this also causes the peeling 37 of the external electrodes 5 and 6 to occur. It can be effectively prevented. Further, it is possible to effectively prevent peeling between the dielectric layer 2 between the dummy electrodes 3b and 4b and the external electrodes 5 and 6 and the dummy electrodes 3b and 4b.

  Furthermore, since one or two metal particles M are present in the dielectric layer 2, the entire metal particles have an indefinite shape and do not fall off the dielectric layer 2 due to external impact or the like.

  Furthermore, the mechanical connection through the metal particles M can be performed by sintering the metal particles M and the metal fine particles m in the dummy electrodes 3b and 4b, and between the metal particles M and the metal fine particles m in the external electrodes 5 and 6. Since it is made by sintering, the mechanical connection can be realized without significantly changing the production line, and the metal particles M, the dummy electrodes 3b and 4b, and the external electrodes 5 and 6 are integrated. This also effectively prevents the external electrodes 5 and 6 from being peeled off.

  Furthermore, the particle size A of the metal particles M present in the dielectric layer 2 is 100 with respect to the thickness B of the dielectric layer 2 located between the extended portions of the dummy electrodes 3b and 4b and the external electrodes 5 and 6. It is desirable that it is set to% to 200%. That is, since the average particle diameter A of the metal particles M corresponds to 100% or more with respect to the thickness B of the dielectric layer 2, the metal particles M penetrate the dielectric layer 2, and the dummy electrodes 3b and 4b and the external electrodes 5 and 6 can be reliably connected. On the other hand, since the average particle diameter A of the metal particles M is 200% or less with respect to the thickness B of the dielectric layer 2, the conductor patterns 3b and 4b serving as dummy electrodes are accurately formed by screen printing or the like during manufacturing. In addition, when the ceramic green sheet 2 and the conductor patterns 3 and 4 to be the large laminate 11 are heated under pressure, it is possible to effectively prevent the adhesion between the ceramic green sheets 2 from being lowered.

  Note that the present invention is not limited to the above-described embodiment, and various modifications and improvements can be made without departing from the scope of the present invention.

  For example, in the above embodiment, the ceramic capacitor is used as the ceramic electronic component. However, the present invention can be used for any ceramic electronic component such as a laminated piezoelectric component, a circuit board, and a semiconductor component.

  FIG. 3 is a cross-sectional view showing a ceramic capacitor according to another embodiment of the present invention. According to the figure, dummy electrodes 3 b and 4 b are also formed on the main surface of the laminate 1. The external electrodes 5 and 6 deposit a metal plating film starting from the dummy electrodes 3b and 4b formed on the main surface of the multilayer body 1 and the exposed portions of the internal electrodes 3a and 4a on the side surfaces of the multilayer body 1. These precipitates are integrally formed by interconnecting each other. In this case, the thickness accuracy of the external electrodes 5 and 6 is improved, and the external electrodes 5 and 6 are formed into a desired pattern by simple processing by simply immersing the laminate 1 in a plating solution for electroless plating for a predetermined time. Therefore, it is possible to improve the productivity of the ceramic capacitor 10. At this time, one dummy dielectric layer 2 is provided between the dummy electrodes 3b and 4b formed on the main surface of the multilayer body 1, and the other dummy electrodes 3b and 4b are buried, and these dummy electrodes are embedded. Since the plurality of metal particles M existing in the dielectric layer 2 between them are sintered and connected to each other, the dummy electrodes 3b and 4b formed on the main surface of the laminate 1 are connected to the laminate 1. It is possible to effectively prevent peeling from the main surface. The external electrodes 5 and 6 and the dummy electrodes 3b and 4b formed on the main surface of the multilayer body 1 are firmly bonded to each other by metal-metal bonding. Further, at this time, the metal particles M to be the metal particles become the other dummy electrodes with the conductor patterns 3b and 4b to be the dummy electrodes formed on the main surface of the multilayer body 1 and the one dielectric layer 2 therebetween. It may be contained in at least one of the conductor patterns 3b and 4b, and may be contained in both. Further, in FIG. 3, the external electrodes 5 and 6 may be formed by baking after applying the conductive paste.

  FIG. 4 is a cross-sectional view showing a ceramic electronic component according to another embodiment of the present invention. As shown in the figure, the ceramic electronic component 10 of the present invention can also be applied to a circuit board 10. Further, the external electrode terminal 5 may be separated from the side surface of the laminate 1. Further, a dummy wiring 4b having a size larger than that of the external electrode terminal 5 and the dummy wiring 3b is embedded, and the dummy wiring 3b and the dummy wiring 4b are electrically connected via the metal particles M existing in the ceramic layer 2 therebetween. You may make it connect mechanically. Thereby, the mechanical connection strength between the external electrode terminal 5 and the laminate 1 main surface can be further increased, and peeling of the external electrode terminal 5 can be further effectively prevented. At this time, if the metal paste M is contained in the conductive paste that becomes the dummy wiring 4b, the metal particles M protrude outside the dummy wiring 3b, so that the dummy wiring 3b and the dummy wiring 4b are conductors that become the dummy wiring 3b. The metal particles M contained in the paste are connected. In the figure, 3a is an internal wiring conductor, 7 is a via-hole conductor, and 8 is another electronic component.

  The dummy electrodes 3b and 4b may contain the same dielectric component as that of the dielectric layer 2. This can also prevent peeling between the dielectric layer 2 and the dummy electrodes 3b and 4b.

It is a figure which shows the ceramic capacitor which concerns on one Embodiment of this invention, (a) is an external appearance perspective view, (b) is a cross-sectional view. It is sectional drawing for demonstrating the manufacturing method of the ceramic capacitor of FIG. It is a cross-sectional view showing a ceramic capacitor according to another embodiment of the present invention. It is a cross-sectional view showing a ceramic electronic component according to another embodiment of the present invention. It is a cross-sectional view showing a conventional ceramic capacitor.

Explanation of symbols

10. Ceramic electronic parts (capacitors)
1 ····· Laminated body 2 ········ Dielectric layer (ceramic layer)
3, 4 ... wiring conductors 3a, 4a ... internal electrodes 3b, 4b ... dummy wiring (dummy electrodes)
5, 6 ... External electrode (external electrode terminal)
M ... Metal particles

Claims (6)

A wiring conductor is disposed on the surface and / or inside of a multilayer body in which a plurality of ceramic layers are laminated, and an external electrode terminal electrically connected to the wiring conductor is formed on the main surface of the multilayer body. In ceramic electronic components,
A dummy wiring is embedded inside the laminate with a ceramic layer between the external electrode terminals and the dummy wiring and the external electrode terminals are present in the ceramic layer between them. A ceramic electronic component characterized in that it is electrically and mechanically connected via one or two metal particles. The mechanical connection through the metal particles is made by sintering the metal particles and the metal component in the dummy wiring, and sintering the metal particles and the metal component in the external electrode terminal. The ceramic electronic component according to claim 1. The particle size A of the metal particles present in the ceramic layer is set to 100% to 200% with respect to the thickness B of the ceramic layer located between the dummy wiring and the extended portion of the external electrode. The ceramic electronic component according to claim 1, wherein the ceramic electronic component is a ceramic electronic component. An internal electrode is interposed between adjacent dielectric layers in a laminated body in which a plurality of dielectric layers are laminated, and an external electrode electrically connected to an end portion of the internal electrode is provided on a side surface of the laminated body. In a capacitor formed and extending one end of the external electrode to the main surface of the laminate,
A dummy electrode is embedded in the laminated body with a dielectric layer between the extended portion of the external electrode, and the dummy electrode and the extended portion of the external electrode are disposed between both electrodes. A capacitor that is electrically and mechanically connected via one or two metal particles present in the dielectric layer. The mechanical connection via the metal particles is made by sintering the metal particles and the metal component in the dummy electrode, and sintering the metal particles and the metal component in the external electrode. The capacitor according to claim 4. The particle size A of the metal particles present in the dielectric layer is set to 100% to 200% with respect to the thickness B of the dielectric layer located between the extending portion of the dummy electrode and the external electrode. The capacitor according to claim 4 or 5, wherein

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