U.S. patent application number 09/969643 was filed with the patent office on 2002-04-11 for multilayer electronic device.
This patent application is currently assigned to TDK Corporation. Invention is credited to Ahiko, Taisuke, Masuda, Sunao, Togashi, Masaaki.
Application Number | 20020041006 09/969643 |
Document ID | / |
Family ID | 18787660 |
Filed Date | 2002-04-11 |
United States Patent
Application |
20020041006 |
Kind Code |
A1 |
Ahiko, Taisuke ; et
al. |
April 11, 2002 |
Multilayer electronic device
Abstract
The multilayer electronic device comprises a dielectric body
formed by stacking dielectric layers. Flat first internal
electrodes and flat second internal electrodes insulated via
dielectric layers and arranged facing to the first internal
electrodes are alternately stacked. First through-hole electrodes
are connected to the first internal electrodes by penetrating,
penetrate the second internal electrodes without connecting thereto
and extend crossing the internal electrodes. The second
through-hole electrodes are connected to the second internal
electrodes by penetrating, penetrate the first internal electrodes
without connecting thereto and extend crossing the internal
electrodes. The first terminal electrodes are arranged on the outer
surface of the dielectric body and connected to the first
through-hole electrodes. The second terminal electrodes are
arranged on the outer surface of the dielectric body, arranged
alternately with the first terminal electrodes and connected to the
second through-hole electrodes.
Inventors: |
Ahiko, Taisuke; (Akita-ken,
JP) ; Togashi, Masaaki; (Akita-ken, JP) ;
Masuda, Sunao; (Akita-ken, JP) |
Correspondence
Address: |
OLIFF & BERRIDGE, PLC
P.O. BOX 19928
ALEXANDRIA
VA
22320
US
|
Assignee: |
TDK Corporation
Tokyo
JP
|
Family ID: |
18787660 |
Appl. No.: |
09/969643 |
Filed: |
October 4, 2001 |
Current U.S.
Class: |
257/532 ;
257/534; 257/920; 361/303 |
Current CPC
Class: |
H01G 4/012 20130101;
H01G 4/232 20130101 |
Class at
Publication: |
257/532 ;
257/534; 257/920; 361/303 |
International
Class: |
H01G 004/005; H01L
029/00; H01L 023/52 |
Foreign Application Data
Date |
Code |
Application Number |
Oct 6, 2000 |
JP |
2000-307097 |
Claims
1. A multilayer electronic device, comprising: a dielectric body
formed by stacking dielectric layers; a flat first internal
electrode arranged in said dielectric body; a flat second internal
electrode arranged opposing to said first internal electrode and
insulated via said dielectric layer in the dielectric body; a first
through-hole electrode connected to said first internal electrode
by penetrating, penetrating said second internal electrode without
connecting thereto and extending across these internal electrodes;
a second through-hole electrode connected to said second internal
electrode by penetrating, penetrating said first internal electrode
without connecting thereto and extending across these internal
electrodes; a first terminal electrode arranged on an outer surface
of said dielectric body and connected to said first through-hole
electrode; and a second terminal electrode arranged on the outer
surface of said dielectric body and connected to said second
through-hole electrode.
2. The multilayer electronic device as set forth in claim 1,
characterized in that a plurality of said first internal electrodes
and a plurality of said second internal electrodes are respectively
formed in said dielectric body; and the first internal electrodes
and the second internal electrodes are alternately arranged in said
dielectric body.
3. The multilayer electronic device as set forth in claim 2,
wherein a plurality of first through-hole electrodes and a
plurality of second through-hole electrodes are formed in said
dielectric body and said first through-hole electrodes and said
second through-hole electrodes are arranged next to each other.
4. The multilayer electronic device as set forth in claim 3,
wherein each of said plurality of first through-hole electrodes is
connected to all of the first internal electrodes arranged in said
dielectric body and each of said plurality of second through-hole
electrodes is connected to all of said second internal electrodes
arranged in said dielectric body.
5. The multilayer electronic device as set forth in claim 3,
wherein at least one of said plurality of first internal electrodes
arranged in said dielectric body is not connected to at least one
of said plurality of said first through-hole electrodes; and at
least one of said plurality of second internal electrodes arranged
in said dielectric body is not connected to at least one of said
plurality of said second through-hole electrodes.
6. The multilayer electronic device as set forth in claim 5,
wherein said plurality of first internal electrodes arranged in
said dielectric body have less connection points with said
plurality of first through-hole electrodes on both end sides along
the stacking direction of said dielectric layers and more
connection points at the center portion; and said plurality of
second internal electrodes arranged in said dielectric body have
less connection points with said plurality of second through-hole
electrodes on both end sides along the stacking direction of said
dielectric layers and more connection points at the center
portion.
7. The multilayer electronic device as set forth in claim 1,
wherein said dielectric body is formed to be a hexagonal shape; at
least two facing sides of said dielectric body in the hexagonal
shape are provided with base parts of said first and second
terminal electrodes in the way of extending in parallel
respectively with said first and second through-hole electrodes;
and said first and second terminal electrodes are connected
respectively to the first and second through-hole electrodes at
terminal pad portions bent at a right angle from the base parts of
said first and second terminal electrodes.
8. A multilayer electronic device as set forth in claim 3,
characterized in that said first terminal electrodes connected
respectively to said first through-hole electrodes and said second
terminal electrodes connected to said second internal electrodes
are arranged next to each other on the outer surface of said
dielectric body.
Description
BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The present invention relates to a multilayer electronic
device for reducing an equivalent serial inductance (ESL) able to
be used also as a capacitor array, particularly relates to a
multiterminal multilayer capacitor.
[0003] 2. Description of the Related Art
[0004] A capacitor is widely known as one kind of electronic
devices. Along with CPUs and other devices becoming to have a
higher frequency in recent years, multilayer ceramic chip
capacitors having a small ESL have also come into use. As a
multiterminal capacitor of the related art having a small ESL,
those in the Japanese Unexamined Patent Publications No. 9-17693
and No. 11-144996 and the US Patent Publication U.S. Pat. No.
5,880,925 are known.
[0005] The multiterminal multilayer capacitors of the related art
described in the publications are originally designed to have a
capacitance, however, due to the configurations, they inevitably
have parasitic inductance and that leads to an existence of
equivalent serial inductance. Because an operation frequency
becomes higher as an operation of an CPU becomes high speed in
recent years, multiterminal multilayer capacitors having been used
without any problems result in having too large parasitic
inductance in some cases.
SUMMARY OF THE INVENTION
[0006] The present invention was made in consideration with the
above circumstances and has as an object thereof to provide a
multiterminal multilayer capacitor and other multilayer electronic
devices capable of reducing equivalent serial inductance.
[0007] To attain the above object, according to a first aspect of
the present invention, there is provided a multilayer electronic
device, comprising:
[0008] a dielectric body formed by stacking dielectric layers;
[0009] a flat first internal electrode arranged in the dielectric
body;
[0010] a flat second internal electrode arranged opposing to the
first internal electrode and insulated via the dielectric layer in
the dielectric body;
[0011] a first through-hole electrode connected to the first
internal electrode by penetrating, penetrating the second internal
electrode without connecting thereto and extending across these
internal electrodes;
[0012] a second through-hole electrode connected to the second
internal electrode by penetrating, penetrating the first internal
electrode without connecting thereto and extending across these
internal electrodes;
[0013] a first terminal electrode arranged on an outer surface of
the dielectric body and connected to the first through-hole
electrode; and
[0014] a second terminal electrode arranged on the outer surface of
the dielectric body and connected to the second through-hole
electrode.
[0015] According to the multilayer electronic device of the present
invention, two kinds of first and second through-hole electrodes
alternately become anodes and cathodes when a current flows, and
two kinds of first and second internal electrodes function as
electrodes of a capacitor. Accordingly, magnetic flux generated by
high frequency currents flowing inversely to each other in the two
kinds of first and second through-hole electrodes cancels each
other in the multilayer electronic device and is nullified. As a
result, parasitic inductance in the multilayer electronic device
itself is reduced, and thereby, equivalent serial inductance is
reduced.
[0016] Also, in the present invention, since the internal
electrodes and terminal electrodes are connected via the first and
second through-hole electrodes in a pillar shape wherein the end
portion has a large area, connection becomes firm between the first
and second through-hole electrodes and the first and second
terminal electrodes, and equivalent serial resistance (ESR) becomes
low.
[0017] Preferably, a plurality of the first internal electrodes and
a plurality of the second internal electrodes are respectively
formed in the dielectric body; and
[0018] the first internal electrodes and the second internal
electrodes are alternately arranged in the dielectric body.
[0019] In the case where a plurality of the first internal
electrodes and a plurality of the second internal electrodes are
formed and alternately arranged in the dielectric body as explained
above, a high capacitance can be obtained when the multilayer
electronic device is applied as a capacitor.
[0020] Preferably, a plurality of first through-hole electrodes and
a plurality of second through-hole electrodes are formed in the
dielectric body and the first through-hole electrodes and the
second through-hole electrodes are arranged next to each other.
[0021] As explained above, when the first through-hole electrodes
connected to the first internal electrodes and the second
through-hole electrodes connected to the second internal electrodes
are arranged next to each other in the dielectric body, an effect
that magnetic flux cancels each other further improves due to high
frequency currents flowing inversely to each other.
[0022] Preferably, each of the plurality of first through-hole
electrodes is connected to all of the first internal electrodes
arranged in the dielectric body and each of the plurality of second
through-hole electrodes is connected to all of the second internal
electrodes arranged in the dielectric body.
[0023] In this case, a connection area of the respective
through-hole electrodes and the respective internal electrodes
increases.
[0024] Alternately, in the present invention, at least one of the
plurality of first internal electrodes arranged in the dielectric
body is not connected to at least one of the plurality of the first
through-hole electrodes; and
[0025] at least one of the plurality of second internal electrodes
arranged in the dielectric body is not connected to at least one of
the plurality of the second through-hole electrodes.
[0026] In this case, alternately, the plurality of first internal
electrodes arranged in the dielectric body have less connection
points with the plurality of first through-hole electrodes on both
end sides along the stacking direction of the dielectric layers and
more connection points at the center portion; and
[0027] the plurality of second internal electrodes arranged in the
dielectric body have less connection points with the plurality of
second through-hole electrodes on both end sides along the stacking
direction of the dielectric layers and more connection points at
the center portion.
[0028] By changing the number of connection points of the
through-hole electrodes connected to the internal electrodes in
this way, the effect of magnetic flux cancellation can be
furthermore expected and the parasitic induction further reduced,
because the number of current fluxes alternately flowing in the
direction of the thickness is increased.
[0029] Preferably, the dielectric body is formed to be a hexagonal
shape;
[0030] at least two opposite sides of the dielectric body in the
hexagonal shape are provided with base parts of the first and
second terminal electrodes in the way of extending in parallel
respectively with the first and second through-hole electrodes;
and
[0031] the first and second terminal electrodes are connected
respectively to the first and second through-hole electrodes at
terminal pad portions bent at a right angle from the base parts of
the first and second terminal electrodes.
[0032] When flowing high frequency currents to the terminal
electrodes, as two kinds of internal electrodes connected to the
terminal electrodes via the through-hole electrodes become anodes
and cathodes, currents from the terminal electrodes on two sides
mutually inversely flow to the internal electrodes, which brings an
effect of reducing parasitic inductance.
[0033] Preferably, the first terminal electrodes connected
respectively to the first through-hole electrodes and the second
terminal electrodes connected to the second internal electrodes are
arranged next to each other on the outer surface of the dielectric
body.
[0034] In this case, since the currents flow so that polarities of
adjacent terminal electrodes become different to each other, the
effect of magnetic flux cancellation furthermore improves due to
the high frequency currents flowing in the inversed directions to
each other.
BRIEF DESCRIPTION OF THE DRAWINGS
[0035] Below, a multilayer electronic device according to the
present invention will be explained in detail based on the
drawings, in which:
[0036] FIG. 1 is a perspective view of a multiterminal multilayer
capacitor according to a first embodiment of the present
invention;
[0037] FIG. 2 is a sectional view along the line II-II in FIG.
1;
[0038] FIG. 3 is a sectional view along the line III-III in FIG.
1;
[0039] FIG. 4 is a perspective view within the multiterminal
multilayer capacitor shown in FIG. 1;
[0040] FIG. 5A is a sectional view of a pattern of a first internal
electrode in the multiterminal multilayer capacitor shown in FIG.
1;
[0041] FIG. 5B is a sectional view of a pattern of a second
internal electrode in the multiterminal multilayer capacitor shown
in FIG. 1;
[0042] FIG. 6 is a perspective view of a plurality of ceramic green
sheets used in a production process of the multiterminal multilayer
capacitor shown in FIG. 1;
[0043] FIG. 7 is a sectional view of a multiterminal multilayer
capacitor according to a second embodiment of the present
invention;
[0044] FIG. 8 is a disassembled perspective view of an upper
portion of the multiterminal multilayer capacitor shown in FIG.
7;
[0045] FIG. 9 is a disassembled perspective view of a lower portion
of the multiterminal multilayer capacitor shown in FIG. 7;
[0046] FIG. 10 is a perspective view of a multiterminal multilayer
capacitor according to a comparative example of the present
invention; and
[0047] FIG. 11 is a disassembled perspective view of the inside of
the multiterminal multilayer capacitor shown in FIG. 10.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0048] (First Embodiment)
[0049] As shown in FIG. 1 to FIG. 4, a multiterminal multilayer
capacitor 10 as a multilayer electronic device according to a first
embodiment of the present invention comprises a dielectric body 12.
The dielectric body 12 is a rectangular parallelepiped sintered
body obtained by stacking a plurality of ceramic green sheets for
making dielectric layers and firing the stacked body.
[0050] Inside the dielectric body 12, flat first internal
electrodes 14 shown in FIG. 5A and flat second internal electrodes
16 shown in FIG. 5B are insulated by respective ceramic layers 12A
and alternately stacked in a Z-axis direction. In the illustrated
example, respective four of the first and second internal
electrodes 14 and 16 exist in the dielectric body 12 by being
respectively separated by the ceramic layers 12A as shown in FIG.
4. Accordingly, the first internal electrodes 14 and the second
internal electrodes 16 are arranged facing to each other via the
ceramic layers 12A while being insulated in the dielectric body
12.
[0051] The center of the X-Y plane of the first internal electrodes
14 and the second internal electrodes 16 positions almost the same
position as a center of the X-Y plane of the dielectric body 12.
Also, a length and width of the first internal electrodes 14 and
the second internal electrodes 16 are designed to be a little
shorter than corresponding lengths of sides of the dielectric body
12 in the X direction and Y direction. Therefore, outer
circumferential edge portions of the first internal electrodes 14
and the second internal electrodes 16 have the configuration
designed not to be exposed to end portions of the dielectric body
12.
[0052] In the dielectric body 12, a first through-hole electrode 18
and a second through-hole electrode 20 are alternately arranged
along the longitudinal X direction at the both sides of the Y
direction which is a direction of short sides of the first internal
electrodes 14 and the second internal electrodes 16. The
through-hole electrodes 18 and 20 extend in a pillar shape in the Z
direction so as to cross and penetrate the internal electrodes 14
and 16 and dielectric layer 12A. The both end portions of the
respective through-hole electrodes 18 and 20 are exposed on the
front and back surfaces of the dielectric body 12, where each of
them connects to a first terminal electrode 22 and a second
terminal electrode 24. Note that the internal electrodes 14 and 16
and the through-hole electrodes 18 and 20 are composed, for
example, of a nickel group metal. A material of the terminal
electrodes 22 and 24 may be any as far as it is a conductive
material and is not particularly limited.
[0053] In the present embodiment, as shown in FIG. 1, respective
four of the first and second through-hole electrodes 18 and 20 are
alternately arranged along the longitudinal direction X at the both
sides of the short side direction Y of the dielectric body 12.
Also, one of the mutually facing through-hole electrodes along the
short side direction Y of the dielectric body 12 becomes the first
through-hole electrode 18, while the other through-hole electrode
becomes the second through-hole electrode 20, and they are
alternately arranged.
[0054] As shown in FIG. 5A, the first internal electrode 14 has a
pattern of electrically connecting to all of the first through-hole
electrodes 18 and to none of the second through-hole electrodes 20,
and has escaping holes 34 at positions where the second
through-hole electrode 20 penetrates the dielectric layer 12A. The
inside diameter of the escaping hole 34 is larger than the outside
diameter of the second through-hole electrode 20 so that the second
through-hole electrode 20 and the first internal electrode 14 are
surely insulated.
[0055] As shown in FIG. 5B, the second internal electrode 16 has a
pattern of electrically connecting to all of the second
through-hole electrodes 20 and to none of the first through-hole
electrodes 18, and has escaping holes 34 at positions where the
first through-hole electrode 18 penetrates the dielectric layer
12A. The inside diameter of the escaping hole 34 is larger than the
outside diameter of the first through-hole electrode 18 so that the
first through-hole electrode 18 and the second internal electrode
16 are surely insulated.
[0056] As shown in FIG. 5A and FIG. 5B, the escaping holes 34 are
formed at mutually different positions for the first internal
electrode 16 and the second internal electrode 18. In the present
embodiment, the shape of the escaping hole 34 is a circle partially
notched at a position of the long side of each of the internal
electrodes. In the present embodiment, the outside diameter of the
first through-hole electrode 18 and the second through-hole
electrode 20 is preferably 30 .mu.m to 200 .mu.m and the inside
diameter of the escaping hole 34 is larger than the outside
diameter of the through-hole electrodes preferably by about 20
.mu.m to 200 .mu.m.
[0057] The through-hole electrodes 18 and 20 are arranged near long
side positions of the first internal electrode 14 and the second
internal electrode 16 in the dielectric body 12, and arranged at
positions by which the whole circumference of the through-hole
electrode fits in the internal electrode at the connection points
with the internal electrodes.
[0058] As shown in FIG. 1, the first terminal electrodes 22 and the
second terminal electrodes 24 position on mutually facing two sides
12B along the short side direction Y of the body 12 on the outer
surface of the dielectric body 12 and alternately arranged along
the longitudinal direction X of the body 12. Each of the terminal
electrodes 22 or 24 comprises a base part positioned on the side
12B and a terminal pad part bent at a right angle from the base
part and positioned on the front and back surfaces 12C of the body
12. The base parts of the electrodes 22 and 24 are arranged
substantially parallel to the corresponding through-hole electrodes
18 and 20 and electrically connected to the exposed end portions of
the respective through-hole electrodes 18 and 20 at the terminal
pad parts. Namely, the first terminal electrode 22 is connected to
the first through-hole electrode 18, the second terminal electrode
24 is connected to the second through-hole electrode 20, and the
first terminal electrodes 22 and the second terminal electrodes 24
are alternately arranged next to each other on the opposite sides
12B of the dielectric body 12. In the present embodiment,
respective four of the terminal electrodes 22 and 24 are arranged
on two sides 12B among six planes of the multiterminal multilayer
capacitor 10 in a hexahedral shape.
[0059] Next, production of the multiterminal multilayer capacitor
10 according to the present embodiment will be explained based on
FIG. 6.
[0060] First, as shown in FIG. 6, a plurality of ceramic green
sheets 30A, 30B and 30C made by a dielectric material for
functioning as a capacitor are prepared for the production of the
multiterminal multilayer capacitor 10.
[0061] The upper surface of the ceramic green sheet 30A shown in
FIG. 6 is not printed or spattered any electrodes, while the
ceramic green sheet 30B is printed or spattered, for example, with
a conductive paste in a pattern of the first internal electrode 14
for forming the first internal electrode 14. Also, the ceramic
green sheet 30C is printed or spattered with a conductive paste in
a pattern of the second internal electrode 16 for forming the
second internal electrode 16 in the same way as the first internal
electrode.
[0062] The ceramic green sheets 30A, 30B and 30C are provided with
8 through-holes in total arranged in two lines at mutually a same
position. The first internal electrode layer 14 formed on one
surface of the ceramic green sheet 30B is formed escaping holes 34
alternately in a pattern of forming the second through-hole
electrodes 20 shown in FIG. 1 to FIG. 5 so as not to contact the
through-holes 32. Also, the internal electrode layer 16 formed on
one surface of the ceramic green sheet 30C is formed escaping holes
34 alternately in a pattern of forming the first through-hole
electrodes 18 shown in FIG. 1 to FIG. 5 so as not to contact the
through-holes 32.
[0063] In other words, as shown in FIG. 6, the through-holes 32
positioning second and fourth from the left among through-holes 32
arranged at closer side of the first internal electrodes 14 are
formed with escaping holes 34, each of which is coaxial with the
through-holes 32 and has a larger diameter than the through-holes
32. Also, the through-holes 32 positioning first and third from the
left among through-holes 32 arranged at far side of the first
internal electrodes 14 are formed with escaping holes 34, each of
which is coaxial with the through-holes 32 and has a larger
diameter than the through-holes 32. Furthermore, as shown in FIG.
6, the second internal electrode 16 is formed with escaping holes
34 in the same way as in the above at through-holes 32 located at
positions not provided with the escaping holes 34 on the first
internal electrode 14.
[0064] Then, rectangular ceramic green sheets 30B and 30C are
successively stacked. For example, respective four of these sheets
are alternately stacked and the upper surface of the stacked
respective four of ceramic green sheets is covered with the blank
ceramic green sheet 30A so that the internal electrodes at the
uppermost portion are not exposed.
[0065] After that, they are co-fired. Consequently, the ceramic
green sheets become ceramic layers 12A, the dielectric body 12 is
obtained, furthermore, a nickel metal based past is poured into the
penetrated through-holes 32, and portions without the escaping
holes 34 on the respective internal electrodes 14 and 16 and the
paste are connected. As a result, the first through-hole electrodes
18 connected to the first internal electrodes 14 and the second
through-hole electrodes 20 connected to the second electrodes 16
are formed in the through-holes 32, respectively.
[0066] Finally, first terminal electrodes 22 connected to the first
through-hole electrodes 18 and the second terminal electrodes 24
connected to the second through-hole electrodes 20 are arranged
around the stacked ceramic green sheets, and the multiterminal
multilayer capacitor 10 wherein the terminal electrodes 22 and 24
are arranged respectively on two sides 12B of the dielectric body
12 is obtained. Note that plating processing may be used and a
single metal, such as Ag and Cu, may be used when arranging the
terminal electrodes 22 and 24 on two sides 12B of the dielectric
body 12.
[0067] Next, an operation of the multiterminal multilayer capacitor
10 according to the present embodiment will be explained.
[0068] In the dielectric body 12 formed by stacking dielectric
layers for example made by ceramic, for example, respective four of
the flat first internal electrodes 14 and the second internal
electrodes 16 are alternately arranged facing to each other
separated by the ceramic layers 12A. Also, the first through-hole
electrodes 18 connected to the first internal electrodes 14 by
penetrating without connecting to the second internal electrodes 16
and the second through-hole electrodes 20 connected to the second
internal electrodes 16 by penetrating without connecting to the
first internal electrodes 14 respectively extend crossing the
internal electrodes 14 and 16.
[0069] Furthermore, the first terminal electrodes 22 connected to
the first internal electrodes 14 via the first through-hole
electrodes 18 and the second terminal electrodes 24 connected to
the second internal electrodes 16 via the second through-hole
electrodes 20 are arranged next to each other on two sides 12B
which are the outside surfaces of the dielectric body 12.
[0070] In other words, respective two of the first terminal
electrodes 22 and the second terminal electrodes 24 are arranged on
one of the sides 12B forming the surface of the dielectric body 12,
and on the other side 12B are arranged respective two of the first
terminal electrodes 22 and the second terminal electrodes 24 in the
same way. Also, the two kinds of through-hole electrodes 18 and 20
connected to either one of the two kinds of internal electrodes 14
and 16 facing to each other are connected to the terminal pad parts
22A and 24A of the terminal electrodes 22 and 24 and extend in a
pillar shape along the thickness direction Z of the dielectric body
12. Then, the two kinds of through-hole electrodes 18 and 20
alternately become an anode and a cathode when a current flows and
a voltage is applied to the internal electrodes 14 and 16.
[0071] Consequently, in the multiterminal multilayer capacitor 10
according to the present embodiment, due to a high frequency
current flowing inversely to each other in the two kinds of
through-hole electrodes 18 and 20, magnetic fluxes generated in the
multiterminal multilayer capacitor 10 are mutually canceled and
nullified. As a result, parasitic inductance in the multiterminal
multilayer capacitor itself decreases and thereby, equivalent
serial inductance also decreases.
[0072] Also in the present embodiment, as a result that the
internal electrodes 14 and 16 and the terminal electrodes 22 and 24
are connected via the through-hole electrodes 18 in a pillar shape
having a large area at the end portion, the through-hole electrodes
18 and 20 and the terminal electrodes 22 and 24 are firmly
connected and equivalent serial resistance becomes low.
Furthermore, since a plurality of the first internal electrodes 14
and the second internal electrodes 16 are formed and alternately
arranged in the dielectric body 12, the multiterminal multilayer
capacitance is also capable of obtaining a high electric
capacitance.
[0073] Also, in the present embodiment, the first through-hole
electrode 18 connected to the first internal electrode 14 and the
second through-hole electrode 20 connected to the second internal
electrode 16 respectively penetrate the dielectric body 12 at
positions next to each other. Accordingly, the effect of the
present embodiment of mutual cancellation of the magnetic flux by a
high frequency current flowing inversely to each other further
improves.
[0074] Furthermore, in the present embodiment, the dielectric body
12 is in a hexagonal shape, a plurality of first terminal
electrodes 22 and second terminal electrodes 24 are arranged next
to each other on the mutually opposite two sides 12B of the
dielectric body 12. The terminal electrodes 22 and 24 are connected
to the respective through-hole electrodes 18 and 20 at portions of
the terminal electrodes 22 and 24 bent at the right angle from
their base parts extending in parallel with the through-hole
electrodes 18 and 20.
[0075] Accordingly, the respective terminal electrodes 22 and 24
are made to be alternately an anode and a cathode in the form that
polarities of the adjacent terminal electrodes 22 and 24 of the
respective sides 12B are mutually different at the time of flowing
a high frequency current in the terminal electrodes 22 and 24. As a
result, the high frequency current flows from the terminal
electrodes 22 and 24 of the two sides 12B to the internal
electrodes 14 and 16 inversely to each other, and the magnetic
fluxes generated thereby are mutually canceled and parasitic
inductance furthermore reduces.
[0076] (Second Embodiment)
[0077] Next, a multilayer electronic device according to a second
embodiment will be explained based on the drawings. Note that the
same reference numbers are added to the same components as those
explained in the first embodiment and repetition of the explanation
will be omitted.
[0078] The multiterminal multilayer capacitor 10a according to the
present embodiment comprises four first through-hole electrodes 18
and four second through-hole electrodes 20 in the same way as in
the capacitor 10 of the first embodiment. Note that in the present
embodiment, as shown in FIG. 7 to FIG. 9, a plurality of, for
example, total 16 of the first internal electrodes 14 and the
second internal electrodes 16 are alternately stacked.
[0079] Also, in at least one of the plurality of first internal
electrodes 14 arranged in the dielectric body 12, a pattern of
escaping holes 34 formed on the first internal electrode 14 is
different along the stacking direction of the dielectric layer 12A
so as not to be connected to at least one of the plurality of first
through-hole electrodes 18. Furthermore, in at least one of the
plurality of second internal electrodes 16, a pattern of escaping
holes 34 formed on the second internal electrode 16 is different
along the stacking direction of the dielectric layer 12A so as not
to be connected to at least one of the plurality of second
through-hole electrodes 20.
[0080] Furthermore, in the present embodiment, the plurality of
first internal electrodes 14 arranged in the dielectric body 12
have less number of connection points with the plurality of first
through-hole electrodes 18 and more number at the central portion
on the both sides along the stacking direction of the dielectric
layer 12A. Similarly, the plurality of second internal electrodes
16 have less number of connection points with the plurality of
second through-hole electrodes 20 and more number at the central
portion on the both sides along the stacking direction of the
dielectric layer 12A.
[0081] Specifically, as shown in FIG. 8, seven escaping holes 34
are provided on an uppermost first internal electrode 14 and the
second internal electrode 16 positioned at the second from the top,
respectively. As a result, it is connected to the uppermost first
internal electrode 14 only by one first through-hole electrode 18
among the four first through-hole electrodes 18. Also, it is
connected to the second internal electrode 16 arranged at the
second from the top only by one second through-hole electrode 20
among the four second through-hole electrodes 20.
[0082] Also, six escaping holes 34 are provided on the first
internal electrode 14 positioned at the third from the top and the
second internal electrode 16 positioned at the fourth from the top,
respectively. Consequently, it is connected to the first internal
electrode 14 positioned at the third from the top only by two first
through-hole electrodes 18 among the four first through-hole
electrodes 18. Also, it is connected to the second internal
electrode 16 arranged at the fourth from the top only by two second
through-hole electrodes 20 among the four second through-hole
electrodes 20.
[0083] Furthermore, five escaping holes 34 are provided on the
first internal electrode 14 positioned at the fifth from the top
and the second internal electrode 16 positioned at the sixth from
the top, respectively. Therefore, it is connected to the first
internal electrode 14 arranged at the fifth from the top only by
three first through-hole electrodes 18 among the four first
through-hole electrodes 18. Also, it is connected to the second
internal electrode 16 arranged at the sixth from the top only by
three second through-hole electrodes 20 among the four second
through-hole electrodes 20.
[0084] Furthermore, four escaping holes 34 are provided on the
first internal electrode 14 positioned at the seventh from the top
and the second internal electrode 16 positioned at the eighth from
the top, respectively. Therefore, it is connected to the first
internal electrode 14 arranged at the seventh from the top by all
of the four first through-hole electrodes 18. Also, it is connected
to the second internal electrode 16 arranged at the eighth from the
top by all of the four second through-hole electrodes 20.
[0085] On the other hand, the first internal electrode 14 and the
second internal electrode 16 arranged at the ninth and on from the
top are connected by all of the four first through-hole electrodes
18 and the four second through-hole electrodes 20 in the same way
as the seventh and the eighth ones. As shown in FIG. 9, patterns of
forming the escaping holes 34 on the internal electrodes 14 and 16
stacked on the lower half side are the inverse of the patterns of
forming the escaping holes 34 on the internal electrodes 14 and 16
stacked on the upper half side shown in FIG. 8.
[0086] As explained above, the multiterminal multilayer capacitor
10a according to the present embodiment is configured so that the
internal electrodes 14 and 16 near the upper and lower surfaces 12C
of the body 12 are not connected to a part of the through-hole
electrodes 18 and 20. The multiterminal multilayer capacitor 10a
also brings the same effect of reducing parasitic inductance and
reducing equivalent serial inductance, etc. as in the first
embodiment.
[0087] Note that the present invention is not limited to the above
embodiments and a variety of modifications can be made thereon.
[0088] For example, the number of internal electrodes were made to
be four of each to be eight in total in the first embodiment and
eight of each to be sixteen in total in the second embodiment, but
the number of the internal electrodes is not limited to those.
Also, the number of through-hole electrodes were made to be four of
each to be eight in total in the respective embodiments, but the
number does not have to be those.
[0089] Furthermore, the escaping hole 34 was made to be a partially
notched shape, but instead of that, it may be a perfect circle and
other shapes. Also, when producing the multiterminal multilayer
capacitor 10 or 10a according to the above embodiments,
through-holes were formed before stacking the green sheets, but the
through-holes may be formed after stacking the green sheets.
[0090] Furthermore, a multilayer electronic device according to the
present invention is not limited to the above explained
multiterminal multilayer capacitor, and the present invention may
be applied to other electronic devices.
[0091] Below, the present invention will be explained based on a
further specific example and a comparative example, but the present
invention is not limited to these examples.
EXAMPLE 1
[0092] A multiterminal multilayer capacitor 10 shown in FIG. 1 to
FIG. 6 were actually produced. A shape of the capacitor 10 was a
3216 shape and capacitance of the capacitor was 1 .mu.F. Note that
the 3216 shape indicates a size of about 3.2 mm in length and about
1.6 mm in width.
[0093] As a result of conducting a test of comparing values of an
equivalent serial inductance and an equivalent serial resistance of
the multiterminal multilayer capacitor 10, the equivalent serial
inductance was 50 pH and the equivalent serial resistance was 3
m.OMEGA..
COMPARATIVE EXAMPLE
[0094] As shown in FIG. 10 and FIG. 11, a multiterminal capacitor
110 corresponding to the related art was actually produced. The
capacitor 110 is composed of a multilayer body 112 in a rectangular
parallelepiped shape and configured so that four pairs of internal
electrodes 114 and 116 shown in FIG. 11 are stacked via ceramic
elements.
[0095] Draw out portions 114A and 116A to be drawn out to mutually
facing two sides among four sides of the stacked body 112 are
formed on respective internal electrodes 114 and 116. Also, on
mutually facing two sides among the four sides of the stacked body
are formed totally eight terminal electrodes 118 and 120, four on
each sides, connected to the respective draw out portions 114A and
116A.
[0096] A shape of the capacitor 110 was also the 3216 shape in the
same way as in the first example, and capacitance of the capacitor
was 1 .mu.F.
[0097] As a result of conducting a test of comparing values of
equivalent serial inductance and equivalent serial resistance of
the multiterminal multilayer capacitor 110, the equivalent serial
inductance was 111 pH and the equivalent serial resistance was 6
m.OMEGA..
[0098] Evaluation
[0099] Comparing with the equivalent serial inductance of 111 pH of
the capacitor 110 in the comparative example 1, that of the
capacitor 10 in the example 1 was 50 pH, which was obviously small.
Also, comparing with the equivalent serial resistance of 6 m.OMEGA.
of the capacitor 110 in the comparative example 1, that of the
capacitor 10 of the example 1 was obviously small, 3 m.OMEGA..
* * * * *