U.S. patent application number 13/923438 was filed with the patent office on 2013-12-26 for ceramic electronic component and ceramic electronic apparatus.
The applicant listed for this patent is Murata Manufacturing Co., Ltd.. Invention is credited to Yoshio KAWAGUCHI, Yoichi KURODA, Masaaki TANIGUCHI.
Application Number | 20130342081 13/923438 |
Document ID | / |
Family ID | 49897645 |
Filed Date | 2013-12-26 |
United States Patent
Application |
20130342081 |
Kind Code |
A1 |
KURODA; Yoichi ; et
al. |
December 26, 2013 |
CERAMIC ELECTRONIC COMPONENT AND CERAMIC ELECTRONIC APPARATUS
Abstract
A ceramic electronic component includes a ceramic element, a
first inner electrode, a second inner electrode, an outer
electrode, and a first auxiliary electrode. The first auxiliary
electrode extends to a first surface of the ceramic element. The
first inner electrode extends along a first direction on the first
surface. The first auxiliary electrode extends outward from the
region where the first inner electrode is disposed in the first
direction on the first surface. The outer electrode covers the
first inner electrode and the first auxiliary electrode.
Inventors: |
KURODA; Yoichi;
(Nagaokakyo-shi, JP) ; TANIGUCHI; Masaaki;
(Nagaokakyo-shi, JP) ; KAWAGUCHI; Yoshio;
(Nagaokakyo-shi, JP) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Murata Manufacturing Co., Ltd. |
Nagaokakyo-shi |
|
JP |
|
|
Family ID: |
49897645 |
Appl. No.: |
13/923438 |
Filed: |
June 21, 2013 |
Current U.S.
Class: |
310/366 ;
336/200; 338/22R; 361/301.4 |
Current CPC
Class: |
H01G 4/30 20130101; H01F
27/022 20130101; H01G 4/12 20130101; H01C 7/18 20130101; H01G 4/012
20130101; H01C 7/008 20130101; H01F 17/0013 20130101; H01L 41/0471
20130101; H01L 41/04 20130101; H05K 7/00 20130101 |
Class at
Publication: |
310/366 ;
361/301.4; 338/22.R; 336/200 |
International
Class: |
H01G 4/30 20060101
H01G004/30; H01C 7/00 20060101 H01C007/00; H01F 17/00 20060101
H01F017/00; H01L 41/04 20060101 H01L041/04 |
Foreign Application Data
Date |
Code |
Application Number |
Jun 22, 2012 |
JP |
2012-141243 |
Mar 28, 2013 |
JP |
2013-169132 |
Claims
1. A ceramic electronic component comprising: a ceramic element; at
least one first inner electrode disposed inside the ceramic element
and extending to a first surface of the ceramic element; a second
inner electrode disposed inside the ceramic element, facing the at
least one first inner electrode, and extending to an opposite
surface of the ceramic element, the opposite surface being opposed
to the first surface; an outer electrode arranged on the first
surface of the ceramic element, connected to the at least one first
inner electrode, and including a plated film; and a first auxiliary
electrode disposed inside the ceramic element and extending to the
first surface of the ceramic element; wherein the at least one
first inner electrode extends along a first direction on the first
surface; the first auxiliary electrode extends outward from a
region where the at least one first inner electrode is disposed in
the first direction on the first surface; and the outer electrode
covers the at least one first inner electrode and the first
auxiliary electrode.
2. The ceramic electronic component according to claim 1, wherein
the at least one first inner electrode includes a plurality of
first inner electrodes extending along a second direction
perpendicular or substantially perpendicular to the first
direction; and the first auxiliary electrode is positioned between
the plurality of first inner electrodes.
3. The ceramic electronic component according to claim 1, wherein
the first auxiliary electrode is positioned between the first inner
electrode nearest to a second surface of the ceramic element and
the second surface, the second surface being parallel or
substantially parallel to the first inner electrode.
4. The ceramic electronic component according to claim 1, wherein a
length of the first inner electrode in the first direction on the
first surface is shorter than a length of the first inner electrode
in the first direction in a portion that is most distant from the
first surface inside the ceramic element.
5. The ceramic electronic component according to claim 1, wherein
the first surface includes a principal surface of the ceramic
element.
6. The ceramic electronic component according to claim 1, further
comprising a second auxiliary electrode disposed inside the ceramic
element and extending to the opposite surface of the ceramic
element; wherein the first auxiliary electrode is positioned
outside the second auxiliary electrode in the second direction that
is parallel or substantially perpendicular to the first
direction.
7. The ceramic electronic component according to claim 1, further
comprising a third inner electrode disposed inside the ceramic
element and not extending to the surfaces of the ceramic
element.
8. The ceramic electronic component according to claim 1, wherein
the ceramic element has a rectangular or substantially rectangular
parallelepiped shape.
9. The ceramic electronic component according to claim 1, wherein
the ceramic element includes a plurality of ceramic layers stacked
on each other.
10. The ceramic electronic component according to claim 1, wherein
the ceramic electronic component is one of a capacitor, a
piezoelectric device, a thermistor, and an inductor.
11. The ceramic electronic component according to claim 1, wherein
the at least one first inner electrode is not exposed at any of a
second surface, first and second side surfaces, and first and
second end surfaces of the ceramic element.
12. The ceramic electronic component according to claim 1, wherein
the second inner electrode is not exposed at any of a second
surface, first and second side surfaces, and first and second end
surfaces of the ceramic element.
13. The ceramic electronic component according to claim 1, wherein
the at least one first inner electrode and the second inner
electrode are aligned in a thickness direction of the ceramic
element.
14. The ceramic electronic component according to claim 7, wherein
the third inner electrode is disposed between the at least one
first inner electrode and the second inner electrode.
15. The ceramic electronic component according to claim 6, wherein
the first auxiliary electrode is positioned between the at least
one first inner electrode and an end surface of the ceramic
element.
16. A ceramic electronic apparatus comprising: the ceramic
electronic component according to claim 1; a substrate arranged
such that a principal surface of the substrate faces the opposite
surface in the ceramic electronic component; and at least one wire
electrically connected to the outer electrode.
Description
BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The present invention relates to a ceramic electronic
component and a ceramic electronic apparatus.
[0003] 2. Description of the Related Art
[0004] Traditionally, components, including an integrated circuit
(IC) chip and a ceramic electronic component, may be mounted on a
substrate. The IC chip may be adversely affected by a flux
contained in soldering. To address this issue, the IC chip and the
ceramic electronic component may be electrically connected to each
other by wire bonding. For example, Japanese Unexamined Utility
Model Registration Application Publication No. 5-4451 discloses a
stacked capacitor electrically connected to an IC chip by wire
bonding.
[0005] In recent years, miniaturization of ceramic electronic
components has made it difficult to precisely form outer electrodes
for use in connecting wires to the ceramic electronic components.
One example of a method of precisely forming an outer electrode is
a method of forming the outer electrode directly by plating, as
disclosed in Japanese Unexamined Patent Application Publication No.
2004-327983.
[0006] However, when an outer electrode is formed directly by
plating, moisture tends to enter the inside of the ceramic
electronic component from between the outer electrode and the
ceramic element or other areas. This causes a problem in that the
resistance to moisture in the ceramic electronic component is
reduced.
SUMMARY OF THE INVENTION
[0007] Preferred embodiments of the present invention provide a
ceramic electronic component with a high moisture resistance.
[0008] According to a preferred embodiment of the present
invention, a ceramic electronic component includes a ceramic
element, at least one first inner electrode, a second inner
electrode, an outer electrode, and a first auxiliary electrode. The
ceramic element preferably has a rectangular or substantially
rectangular parallelepiped shape. The at least one first inner
electrode is disposed inside the ceramic element. The first inner
electrode extends to a first surface of the ceramic element. The
second inner electrode is disposed inside the ceramic element. The
second inner electrode faces the at least one first inner
electrode. The second inner electrode extends to an opposite
surface of the ceramic element, the opposite surface being opposed
to the first surface. The outer electrode is arranged on the first
surface of the ceramic element. The outer electrode is connected to
the at least one first inner electrode. The outer electrode is
defined by a plated film. The first auxiliary electrode is disposed
inside the ceramic element. The first auxiliary electrode extends
to the first surface of the ceramic element. The at least one first
inner electrode extends along a first direction on the first
surface. The first auxiliary electrode extends outward from a
region where the at least one first inner electrode is disposed in
the first direction on the first surface. The outer electrode
covers the at least one first inner electrode and the first
auxiliary electrode.
[0009] In a specific aspect of the ceramic electronic component
according to a preferred embodiment of the present invention, the
at least one first inner electrode may include a plurality of first
inner electrodes extending along a second direction perpendicular
or substantially perpendicular to the first direction, and the
first auxiliary electrode may be positioned between the plurality
of first inner electrodes.
[0010] In another specific aspect of the ceramic electronic
component according to a preferred embodiment of the present
invention, the first auxiliary electrode may be positioned between
the first inner electrode nearest to a second surface of the
ceramic element and the second surface, the second surface being
parallel or substantially parallel to the first inner
electrode.
[0011] In yet another specific aspect of the ceramic electronic
component according to a preferred embodiment of the present
invention, the length of the first inner electrode in the first
direction on the first surface may be shorter than the length of
the first inner electrode in the first direction in a portion that
is the most distant from the first surface inside the ceramic
element.
[0012] In still another specific aspect of the ceramic electronic
component according to a preferred embodiment of the present
invention, the first surface may be a principal surface.
[0013] In another specific aspect of the ceramic electronic
component according to a preferred embodiment of the present
invention, the ceramic electronic component may further include a
second auxiliary electrode disposed inside the ceramic element and
extending to the opposite surface of the ceramic element. The first
auxiliary electrode may be positioned outside the second auxiliary
electrode in the second direction that is perpendicular or
substantially perpendicular to the first direction.
[0014] In yet another aspect of the ceramic electronic component
according to a preferred embodiment of the present invention, the
ceramic electronic component may further include a third inner
electrode disposed inside the ceramic element and not extending to
the surfaces of the ceramic element.
[0015] According to another preferred embodiment of the present
invention, a ceramic electronic apparatus includes the
above-described ceramic electronic component, a substrate, and
wire. The substrate is arranged such that a principal surface of
the substrate faces the opposite surface in the ceramic electronic
component. The wire is electrically connected to the outer
electrode.
[0016] The above and other elements, features, steps,
characteristics and advantages of the present invention will become
more apparent from the following detailed description of the
preferred embodiments with reference to the attached drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0017] FIG. 1 is a schematic perspective view of a ceramic
electronic component according to a first preferred embodiment of
the present invention.
[0018] FIG. 2 is a schematic cross-sectional view of the ceramic
electronic component according to the first preferred embodiment of
the present invention.
[0019] FIG. 3 is a schematic plan view of the ceramic electronic
component according to the first preferred embodiment of the
present invention.
[0020] FIG. 4 is a schematic back-side view of the ceramic
electronic component according to the first preferred embodiment of
the present invention.
[0021] FIG. 5 is a schematic cross-sectional view taken along the
line V-V in FIG. 2.
[0022] FIG. 6 is a schematic cross-sectional view taken along the
line VI-VI in FIG. 2.
[0023] FIG. 7 is a schematic cross-sectional view of a ceramic
electronic apparatus according to a preferred embodiment of the
present invention.
[0024] FIG. 8 is a schematic cross-sectional view of a ceramic
electronic component according to a second preferred embodiment of
the present invention.
[0025] FIG. 9 is a schematic plan view of the ceramic electronic
component according to the second preferred embodiment of the
present invention.
[0026] FIG. 10 is a schematic back-side view of the ceramic
electronic component according to the second preferred embodiment
of the present invention.
[0027] FIG. 11 is a schematic cross-sectional view taken along the
line XI-XI in FIG. 8.
[0028] FIG. 12 is a schematic cross-sectional view taken along the
line XII-XII in FIG. 8.
[0029] FIG. 13 is a schematic cross-sectional view of a ceramic
electronic component according to a third preferred embodiment of
the present invention.
[0030] FIG. 14 is a schematic cross-sectional view of a ceramic
electronic component according to a fourth preferred embodiment of
the present invention.
[0031] FIG. 15 is a schematic cross-sectional view of a ceramic
electronic component according to a fifth preferred embodiment of
the present invention.
[0032] FIG. 16 is a schematic cross-sectional view of a ceramic
electronic component according to a sixth preferred embodiment of
the present invention.
[0033] FIG. 17 is a schematic plan view of the ceramic electronic
component according to the sixth preferred embodiment of the
present invention.
[0034] FIG. 18 is a schematic cross-sectional view of a ceramic
electronic component according to a seventh preferred embodiment of
the present invention.
[0035] FIG. 19 is a schematic plan view of the ceramic electronic
component according to the seventh preferred embodiment of the
present invention.
[0036] FIG. 20 is a schematic cross-sectional view of a ceramic
electronic component according to an eighth preferred embodiment of
the present invention.
[0037] FIG. 21 is a schematic plan view of the ceramic electronic
component according to the eighth preferred embodiment of the
present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0038] Preferred embodiments of the present invention will be
further described below. The preferred embodiments below are merely
illustrative. The present invention is not limited to the preferred
embodiments described below.
[0039] Members having substantially the same functions are referred
to using the same reference numerals in the drawings referred to in
the description of the preferred embodiments of the present
invention. The drawings referred to in the description of the
preferred embodiments of the present invention are schematically
illustrated, and the ratios of the dimensions of elements in the
drawings may be different from those of actual elements. The ratios
of the dimensions of objects may be different among the drawings.
Specific ratios of the dimensions of elements should be construed
in consideration of the description below.
First Preferred Embodiment
[0040] FIG. 1 is a schematic perspective view of a ceramic
electronic component according to a first preferred embodiment of
the present invention. FIG. 2 is a schematic cross-sectional view
of the ceramic electronic component according to the first
preferred embodiment. FIG. 3 is a schematic plan view of the
ceramic electronic component according to the first preferred
embodiment. FIG. 4 is a schematic back-side view of the ceramic
electronic component according to the first preferred embodiment.
FIG. 5 is a schematic cross-sectional view taken along the line V-V
in FIG. 2. FIG. 6 is a schematic cross-sectional view taken along
the line VI-VI in FIG. 2.
[0041] As illustrated in FIGS. 1 to 6, a ceramic electronic
component 1 includes a ceramic element 10. The ceramic element 10
preferably has the shape of a rectangular or substantially
rectangular parallelepiped. The ceramic element 10 includes first
and second principal surfaces 10a and 10b facing each other, first
and second side surfaces 10c and 10d facing each other, and first
and second end surfaces 10e and 10f facing each other. Each of the
first and second principal surfaces 10a and 10b extends along the
length direction L and width direction W. Each of the first and
second side surfaces 10c and 10d extends along the length direction
L and thickness direction T. Each of the first and second end
surfaces 10e and 10f extends along the width direction W and
thickness direction T. The length direction L and width direction W
are perpendicular or substantially perpendicular to each other. The
thickness direction T is perpendicular or substantially
perpendicular to each of the length direction L and width direction
W.
[0042] The dimension in the length direction L and the dimension in
the width direction W in the ceramic element 10 are the same or
substantially the same.
[0043] In the present invention, a "substantially rectangular
parallelepiped" contains a substantially rectangular parallelepiped
including a rounded corner or ridge. That is, the ceramic element
10 may have the shape of a substantially rectangular parallelepiped
whose corners and ridges are rounded at least in part.
[0044] As illustrated in FIG. 2, the ceramic element 10 is a
laminated member in which a plurality of ceramic portions (ceramic
layers) 15 are stacked along the length direction L. The thickness
of each of the ceramic portions 15 may preferably be about 0.5
.mu.m to about 10 .mu.m, for example.
[0045] The ceramic element 10 is made of any suitable ceramic
material. The ceramic material of the ceramic element 10 is
suitably selected depending on the characteristics of the ceramic
electronic component 1.
[0046] As an example, when the ceramic electronic component 1 is a
ceramic capacitor device, the ceramic element 10 can be made of a
material whose chief ingredient is a dielectric ceramic. Specific
examples of the dielectric ceramic can include barium titanate
(BaTiO.sub.3), calcium titanate (CaTiO.sub.3), strontium titanate
(SrTiO.sub.3), and calcium zirconate (CaZrO.sub.3). An accessory
ingredient, such as a manganese compound, a magnesium compound, a
silicon compound, a cobalt compound, a nickel compound, or a
rare-earth compound, may also be suitably added to the ceramic
element 10.
[0047] As another example, when the ceramic electronic component 1
is a ceramic piezoelectric device, the ceramic element 10 can be
made of a material whose chief ingredient is a piezoelectric
ceramic. Specific examples of the piezoelectric ceramic can include
a PZT-based ceramic.
[0048] As yet another example, when the ceramic electronic
component 1 is a thermistor device, the ceramic element 10 can be
made of a semiconductor ceramic. Specific examples of the
semiconductor ceramic can include a spinel-based ceramic.
[0049] As still another example, when the ceramic electronic
component 1 is an inductor device, the ceramic element 10 can be
made of a magnetic ceramic. Specific examples of the magnetic
ceramic can include a ferrite ceramic.
[0050] In the present preferred embodiment, an example in which the
ceramic electronic component 1 is a ceramic capacitor and the
ceramic element 10 is made of a material whose chief ingredient is
a dielectric ceramic is described below.
[0051] The ceramic electronic component 1 further includes a
plurality of first inner electrodes 11 and a plurality of second
inner electrodes 12 disposed inside the ceramic element 10. Each of
the first and second inner electrodes 11 and 12 extends along the
thickness direction T and width direction W inside the ceramic
element 10. The plurality of first and second inner electrodes 11
and 12 are arranged along the length direction L. The first and
second inner electrodes 11 and 12 are alternately arranged along
the length direction L. The first and second inner electrodes 11
and 12 face each other in the length direction L such that the
ceramic portion 15 is disposed therebetween. In the present
invention, the first and second inner electrodes 11 and 12 are not
necessarily required to face each other such that the ceramic
portion 15 is disposed therebetween.
[0052] The first inner electrodes 11 extend to the first principal
surface 10a. The first inner electrodes 11 extend along the width
direction W in the first principal surface 10a. The first inner
electrodes 11 are exposed to none of the second principal surface
10b, which is the opposite surface positioned on the opposite side
of the first principal surface 10a, the first and second side
surfaces 10c and 10d, and the first and second end surfaces 10e and
10f.
[0053] In the present preferred embodiment, as illustrated in FIG.
5, the length X1 of each of the first inner electrodes 11 along the
width direction W in the first principal surface 10a is shorter
than the length X2 of the first inner electrode 11 along the width
direction W in the most distant portion from the first principal
surface 10a inside the ceramic element 10. The present invention is
not limited to this preferred embodiment. In the present invention,
the length of the first inner electrode 11 along the width
direction W in the first principal surface 10a may be the same as
or may be longer than the length of the first inner electrode 11
along the width direction W inside the ceramic element 10. From the
viewpoint of increasing the area where the first and second inner
electrodes 11 and 12 face each other and ensuring the capacity, the
length of the first inner electrode 11 along the width direction W
inside the ceramic element 10 may preferably be longer than the
length of the first inner electrode 11 along the width direction W
in the first principal surface 10a.
[0054] The second inner electrodes 12 extend to the second
principal surface 10b. The second inner electrodes 12 extend along
the width direction W in the second principal surface 10b. The
second inner electrodes 12 are exposed to none of the first
principal surface 10a, the first and second side surfaces 10c and
10d, and the first and second end surfaces 10e and 10f.
[0055] In the present preferred embodiment, as illustrated in FIG.
6, the length X3 of each of the second inner electrodes 12 along
the width direction W in the second principal surface 10b is
shorter than the length X4 of the second inner electrode 12 along
the width direction W inside the ceramic element 10. The present
invention is not limited to this preferred embodiment. In the
present invention, the length of the second inner electrode 12
along the width direction W in the second principal surface 10b may
be the same as or may be longer than the length of the second inner
electrode 12 along the width direction W inside the ceramic element
10. From the viewpoint of increasing the area where the first and
second inner electrodes 11 and 12 face each other and ensuring the
capacity, the length of the second inner electrode 12 along the
width direction W inside the ceramic element 10 may preferably be
longer than the length of the second inner electrode 12 along the
width direction W in the second principal surface 10b.
[0056] The thickness of each of the first and second inner
electrodes 11 and 12 may preferably be about 0.3 .mu.m to about 2.0
.mu.m, for example.
[0057] The first and second inner electrodes 11 and 12 can be any
conductive element and are not particularly limited. Each of the
first and second inner electrodes 11 and 12 can be made of a metal,
such as nickel, copper, silver, palladium, or gold, or an alloy
that includes at least one of these metals, such as a
silver-palladium alloy.
[0058] The ceramic electronic component 1 further includes
rectangular or substantially rectangular first and second auxiliary
electrodes 16 and 17 disposed inside the ceramic element 10. In the
present invention, an "auxiliary electrode" is an electrode that
does not virtually contribute to achieving the functions of the
ceramic electronic component. Each of the first and second
auxiliary electrodes 16 and 17 can be made of the same metal or
alloy as that of each of the first and second inner electrodes.
[0059] As illustrated in FIG. 3, at least one of the plurality of
first auxiliary electrodes 16 is positioned between the plurality
of first inner electrodes 11. At least one of the plurality of
first auxiliary electrodes 16 is positioned between the first inner
electrode 11 nearest to the first end surface 10e, which is a
surface of the ceramic element 10 that is parallel or substantially
parallel to the first inner electrodes 11, and the first end
surface 10e. At least one of the plurality of first auxiliary
electrodes 16 is positioned between the first inner electrode 11
nearest to the second end surface 10f, which is a surface of the
ceramic element 10 that is parallel or substantially parallel to
the first inner electrodes 11, and the second end surface 10f.
[0060] The first auxiliary electrodes 16 extend to the first
principal surface 10a. The first auxiliary electrodes 16 extend
along the width direction W in the first principal surface 10a. The
first auxiliary electrodes 16 are exposed to none of the second
principal surface 10b, the first and second side surfaces 10c and
10d, and the first and second end surfaces 10e and 10f. The first
auxiliary electrodes 16 extend outward from the region where the
first inner electrodes 11 are disposed in the width direction W in
the first principal surface 10a.
[0061] As illustrated in FIG. 4, at least one of the plurality of
second auxiliary electrodes 17 is positioned between the plurality
of second inner electrodes 12. At least one of the plurality of
second auxiliary electrodes 17 is positioned between the second
inner electrode 12 nearest to the first end surface 10e, which is a
surface of the ceramic element 10 that is parallel or substantially
parallel to the second inner electrodes 12, and the first end
surface 10e. At least one of the plurality of second auxiliary
electrodes 17 is positioned between the second inner electrode 12
nearest to the second end surface 10f, which is a surface of the
ceramic element 10 that is parallel or substantially parallel to
the second inner electrodes 12, and the second end surface 10f.
[0062] The second auxiliary electrodes 17 are exposed to none of
the first principal surface 10a, the first and second side surfaces
10c and 10d, and the first and second end surfaces 10e and 10f. The
second auxiliary electrodes 17 extend outward from the region where
the second inner electrodes 12 are disposed in the width direction
W in the second principal surface 10b. As illustrated in FIG. 3,
the ceramic electronic component 1 includes first auxiliary
electrodes positioned outside the second auxiliary electrodes 17 in
the length direction L, which is perpendicular or substantially
perpendicular to the width direction W.
[0063] An outer electrode 20 is arranged on each of the first and
second principal surfaces 10a and 10b of the ceramic element 10.
The outer electrode 20 on the first principal surface 10a is
connected to the first inner electrodes 11. The outer electrode 20
on the second principal surface 10b is connected to the second
inner electrodes 12. The outer electrode 20 on the first principal
surface 10a covers the first inner electrodes 11 and the first
auxiliary electrodes 16. The outer electrode 20 on the second
principal surface 10b covers the second inner electrodes 12 and the
second auxiliary electrodes 17.
[0064] The outer electrode 20 is preferably defined by at least one
plated film. The outer electrode 20 may include a laminate of a
plurality of plated films. The thickness of one plated film may
preferably be about 1 .mu.m to about 15 .mu.m, for example.
[0065] The outer electrode 20 can be made of a metal, such as
copper, nickel, tin, extend, gold, silver, palladium, bismuth, or
zinc, or an alloy that includes at least one of these metals, for
example. The outer electrode 20 may preferably include a
three-layer structure of copper, nickel, and gold or a two-layer
structure of nickel and gold, for example.
[0066] Next, one example of a method of manufacturing the ceramic
electronic component 1 will be described.
[0067] First, a ceramic green sheet including a ceramic material
for forming the ceramic element 10 is prepared. Then, a conductive
pattern is formed on the ceramic green sheet by applying conductive
paste.
[0068] Then, a plurality of ceramic green sheets with no conductive
patterns, ceramic green sheets each including a conductive pattern
of the shape corresponding to the first or second inner electrode
11 or 12 or the first or second auxiliary electrode 16 or 17, a
plurality of ceramic green sheets with no conductive patterns are
stacked in this order, and the laminate is pressed in the stacking
direction, so as to produce the mother laminate.
[0069] Then, the mother laminate is cut along virtual cutting lines
thereon, so as to produce a plurality of green ceramic laminates
from the mother laminate.
[0070] Then, the green ceramic laminates are fired. In this firing
process, the first and second inner electrodes 11 and 12 and the
first and second auxiliary electrodes 16 and 17 are fired.
[0071] Then, the outer electrode 20, which will be formed from a
plated film, is formed on each of the fired ceramic laminates by
plating. In this way, the ceramic electronic component 1 can be
manufactured.
[0072] In the ceramic electronic component 1, the first auxiliary
electrodes 16 extend outward from the region where the first inner
electrodes 11 are disposed in the width direction W in the first
principal surface 10a. Accordingly, if plating solution used in
forming a plated film or moisture in the atmosphere enters the
surface of the outer electrode from between the ceramic element 10
and the outer electrode 20, the path along which the moisture will
reach the first inner electrodes 11 can be extended. In other
words, the moisture entering from between the edge of the outer
electrode 20 and the ceramic element 10 tends to enter the first
auxiliary electrodes 16 before reaching the first inner electrodes
11. Thus a decrease in insulation resistance does not easily occur
in the first inner electrodes 11. Accordingly, the ceramic
electronic component 1 is highly resistant to moisture.
[0073] In connecting wire to the outer electrode in the ceramic
electronic component, the outer electrode may be separated from the
ceramic element, depending on the force on the outer electrode
during connecting the wire or after connecting the wire. For the
ceramic electronic component 1, because the area of the region
where the plated film forming the outer electrode 20 and the first
auxiliary electrodes 16 are attached to each other is large, the
adhesive strength of the outer electrode 20 to the ceramic element
is high. Accordingly, when the wire is connected to the outer
electrode 20 on the first principal surface 10a, the outer
electrode 20 is not easily separated from the ceramic element
10.
[0074] One or more of the first auxiliary electrodes 16 are
positioned between the first inner electrode 11 nearest to the
first end surface 10e of the ceramic element 10 and the first end
surface 10e in the ceramic electronic component 1. Thus, the
adhesive strength between the outer electrode 20 and the ceramic
element 10 at the end portion of the outer electrode 20 is higher.
Another one or more of the first auxiliary electrodes 16 are
positioned between the first inner electrode 11 nearest to the
second end surface 10f of the ceramic element 10 and the second end
surface 10f. Thus, the adhesive strength between the outer
electrode 20 and the ceramic element 10 at the end portion of the
outer electrode 20 is higher.
[0075] The area of the first auxiliary electrodes 16 is larger than
that of the first inner electrodes 11 in the first principal
surface 10a in the ceramic electronic component 1. Thus, the
adhesive strength between the outer electrode 20 and the ceramic
element 10 is further increased.
[0076] The first principal surface 10a, to which the first
auxiliary electrodes 16 are exposed, is a principal surface whose
area is larger than each of the first and second side surfaces 10c
and 10d and the first and second end surfaces 10e and 10f. Thus,
the area of the outer electrode 20 is large. In such a case, the
advantageous effect achieved by an increase in adhesive strength
between the ceramic element 10 and the outer electrode 20 is
great.
[0077] The ceramic electronic component 1 can be used as a
component in a ceramic electronic apparatus 1a illustrated in FIG.
7, for example. The ceramic electronic apparatus 1a includes the
ceramic electronic component 1, a substrate 50, and wire 80. The
ceramic electronic component 1 is arranged such that the second
principal surface 10b faces a principal surface 50a of the
substrate 50. The substrate 50 is provided with a land 60. The
ceramic electronic component 1 is arranged such that the outer
electrode 20 on the second principal surface 10b faces the land 60
with a curing agent 70 of conductive adhesive being disposed
therebetween.
[0078] The wire 80 is electrically connected to the outer electrode
20 on the first principal surface 10a such that the curing agent 70
of conductive adhesive is disposed therebetween.
[0079] The ratio of the area of the first auxiliary electrodes 16
in the first principal surface 10a to that of the first inner
electrodes 11 is larger than the ratio of the area of the second
auxiliary electrodes 17 in the second principal surface 10b to that
of the second inner electrodes 12 in the ceramic electronic
component 1. Thus, for example, the area of the outer electrode 20
on the first principal surface 10a can be large, and the area of
the outer electrode 20 on the second principal surface 10b can be
small. If the area of the outer electrode 20 on the first principal
surface 10a is large, it is easy to connect wire to the outer
electrode 20 on the first principal surface 10a. If the area of the
outer electrode 20 on the second principal surface 10b is small, a
problem, such as a short circuit caused by the outer electrode 20
coming into contact with another electronic component, does not
easily occur in arranging the outer electrode 20 directly above the
land 60 on the substrate 50, as illustrated in FIG. 7.
[0080] Other examples of preferred embodiments of the present
invention are described below. In the following description,
members having substantially common functions as in the above first
preferred embodiment are referred to using common reference
numerals, and the description thereof is omitted.
Second Preferred Embodiment
[0081] FIG. 8 is a schematic cross-sectional view of a ceramic
electronic component according to a second preferred embodiment of
the present invention. FIG. 9 is a schematic plan view of the
ceramic electronic component according to the second preferred
embodiment. FIG. 10 is a schematic back-side view of the ceramic
electronic component according to the second preferred embodiment.
FIG. 11 is a schematic cross-sectional view taken along the line
XI-XI in FIG. 8. FIG. 12 is a schematic cross-sectional view taken
along the line XII-XII in FIG. 8.
[0082] As illustrated in FIGS. 8 to 12, in a ceramic electronic
component 2, the first inner electrodes 11 and the second inner
electrodes 12 are aligned in the thickness direction T. The first
auxiliary electrodes 16 and the second auxiliary electrodes 17 are
aligned in the thickness direction T.
[0083] The ceramic electronic component 2 includes third inner
electrodes 13. The third inner electrodes 13 do not extend to the
surfaces of the ceramic element 10. The third inner electrodes 13
are positioned between the plurality of first inner electrodes 11
and the plurality of second inner electrodes 12 and face each of
the first inner electrodes 11 and the second inner electrodes 12 in
the thickness direction T. The third inner electrodes 13 and the
first and second auxiliary electrodes 16 and 17 are aligned in the
thickness direction T. The ceramic electronic component 2 can also
provide substantially the same advantageous effects as in the
ceramic electronic component 1.
Third Preferred Embodiment
[0084] FIG. 13 is a schematic cross-sectional view of a ceramic
electronic component according to a third preferred embodiment of
the present invention. As illustrated in FIG. 13, a ceramic
electronic component 3 according to the third preferred embodiment
includes the third inner electrodes 13, as in the ceramic
electronic component 2 according to the second preferred
embodiment. One or more of the first auxiliary electrodes 16 are
positioned between the first inner electrode 11 nearest to the
first end surface 10e of the ceramic element 10 and the first end
surface 10e in the ceramic electronic component 3. Another one or
more of the first auxiliary electrodes 16 are positioned between
the first inner electrode 11 nearest to the second end surface 10f
of the ceramic element 10 and the second end surface 10f. Thus, the
adhesive strength between the outer electrode 20 and the ceramic
element 10 is higher.
Fourth Preferred Embodiment
[0085] FIG. 14 is a schematic cross-sectional view of a ceramic
electronic component according to a fourth preferred embodiment of
the present invention. As illustrated in illustrated in FIG. 14, a
ceramic electronic component 4 according to the fourth preferred
embodiment includes the third inner electrodes 13, as in the
ceramic electronic component 2 according to the second preferred
embodiment. One or more of the first auxiliary electrodes 16 are
positioned between the first inner electrode 11 nearest to the
first end surface 10e of the ceramic element 10 and the first end
surface 10e in the ceramic electronic component 4, as in the
ceramic electronic component 3 according to the third preferred
embodiment. Another one or more of the first auxiliary electrodes
16 are positioned between the first inner electrode 11 nearest to
the second end surface 10f of the ceramic element 10 and the second
end surface 10f. In the ceramic electronic component 4, one or more
of the third inner electrodes 13 are also positioned between the
first inner electrode 11 nearest to the first end surface 10e of
the ceramic element 10 and the first end surface 10e. Another one
or more of the third inner electrodes 13 are also positioned
between the first inner electrode 11 nearest to the second end
surface 10f of the ceramic element 10 and the second end surface
10f. The ceramic electronic component 4 may be preferable in terms
of its manufacturing cost because the arrangement of the inner
electrodes can be made up of two kinds of patterns.
Fifth Preferred Embodiment
[0086] FIG. 15 is a schematic cross-sectional view of a ceramic
electronic component according to a fifth preferred embodiment of
the present invention. As illustrated in FIG. 15, a ceramic
electronic component 5 according to the fifth preferred embodiment
includes the third inner electrodes 13, as in the ceramic
electronic component 2 according to the second preferred
embodiment. In the ceramic electronic component 5, the plurality of
first auxiliary electrodes 16 are arranged between the first inner
electrodes 11. Thus the probability that moisture from between the
outer electrode 20 and the ceramic element 10 will reach an
auxiliary electrode is higher than the probability that the
moisture will reach an inner electrode. Accordingly, the ceramic
electronic component 5 has a high resistance to moisture.
Sixth Preferred Embodiment
[0087] FIGS. 16 and 17 are a schematic cross-sectional view and a
schematic plan view, respectively, of a ceramic electronic
component according to a sixth preferred embodiment of the present
invention.
[0088] The first inner electrodes 11 and second inner electrodes 12
in the ceramic electronic component 6 according to the sixth
preferred embodiment are arranged in the ceramic element 10 in
substantially the same manner as in the first preferred embodiment.
In the present preferred embodiment, each of the first inner
electrodes 11 and second inner electrodes 12 is a split inner
electrode. That is, the first inner electrode includes two
electrode layers 11a and 11b connected to the same potential. The
electrode layers 11a and 11b overlap each other such that a ceramic
layer is disposed therebetween. The second inner electrode 12
includes two electrode layers 12a and 12b, as in the first inner
electrode 11. As in this case, each of the first and second inner
electrodes may be a split inner electrode.
[0089] The first and second auxiliary electrodes 16 and 17 are also
disposed in the sixth preferred embodiment, as in the first
preferred embodiment. Each of the first auxiliary electrodes 16 is
a split electrode including two electrode layers 16a and 16b, and
each of the second auxiliary electrodes 17 is a split electrode
including two electrode layers 17a and 17b.
[0090] The description is provided below using the first auxiliary
electrodes 16 with reference to FIG. 17. The first auxiliary
electrodes 16 extend outward from the region where the first inner
electrodes 11 are disposed in the width direction W. Accordingly,
the resistance to moisture can be enhanced, as in the first
preferred embodiment.
[0091] In the present preferred embodiment, as illustrated in FIG.
17, third auxiliary electrodes 21 are disposed in the ceramic
element 10. The third auxiliary electrodes 21 are exposed to the
region where the first inner electrodes 11 are disposed in the
width direction W and do not reach the portion outside that region
in the width direction W. As in this case, an auxiliary electrode
such as the third auxiliary electrode 21 may be further included as
another auxiliary electrode that does not reach the region where
the inner electrodes are disposed in the present invention. The
other respects of the sixth preferred embodiment are substantially
the same as in the first preferred embodiment.
Seventh Preferred Embodiment
[0092] FIGS. 18 and 19 are a schematic cross-sectional view and a
schematic plan view of a ceramic electronic component 7 according
to a seventh preferred embodiment, respectively. The ceramic
electronic component 7 according to the present preferred
embodiment is substantially the same as the sixth preferred
embodiment, except for where the first and second auxiliary
electrodes 16 and 17 are formed. The difference is that the first
auxiliary electrodes 16 are positioned over the end portion of the
region where the first inner electrodes 11 are disposed in the
first principal surface 10a in the width direction W, as
illustrated in FIG. 19. In other words, the first auxiliary
electrodes 16 do not reach the central region of each of the first
and second inner electrodes 11 and 12 in the width direction W.
[0093] Although not explicitly illustrated in FIG. 19, the second
auxiliary electrodes 17 illustrated in FIG. 18 also do not reach
the central region in the width direction W in the second principal
surface 10b, to which the second inner electrodes 12 are exposed.
As in this case, the first and second auxiliary electrodes 16 and
17 may be arranged only in the vicinity of the end portion where
the first and second inner electrodes 11 and 12 are disposed so as
to be positioned over that end portion in the present
invention.
Eighth Preferred Embodiment
[0094] FIGS. 20 and 21 are a schematic cross-sectional view and a
schematic plan view, respectively, of a ceramic electronic
component according to an eighth preferred embodiment of the
present invention.
[0095] A ceramic electronic component 8 according to the eighth
preferred embodiment is substantially the same as the sixth
preferred embodiment, except for the first and second auxiliary
electrodes 16 and 17. In the present preferred embodiment, as
illustrated in FIG. 21, the first auxiliary electrodes 16 reach
both ends in the width direction W in the first principal surface
10a. That is, the first auxiliary electrodes 16 reach both ends in
the width direction W inside the ceramic element 10, in other
words, both the first and second side surfaces 10c and 10d. The
second auxiliary electrodes 17 are disposed in substantially the
same manner.
[0096] Accordingly, the first and second auxiliary electrodes 16
and 17 are exposed to the first and second side surfaces 10c and
10d. Thus, it is desirable that the outer electrode 20 be formed so
as to include a folded portion that reaches the first and second
side surfaces 10c and 10d. Because the first and second auxiliary
electrodes 16 and 17 are exposed to the first and second side
surfaces 10c and 10d, the folded portion can be formed reliably.
This can enable the path along which plating solution or moisture
from the outside will reach the first and second inner electrodes
11 and 12 to be longer than that in each of the first preferred
embodiment and sixth preferred embodiment. Accordingly, the
resistance to moisture can be further enhanced, as described
above.
[0097] While preferred embodiments of the present invention have
been described above, it is to be understood that variations and
modifications will be apparent to those skilled in the art without
departing from the scope and spirit of the present invention. The
scope of the present invention, therefore, is to be determined
solely by the following claims.
* * * * *