JP3727542B2 - Multilayer feedthrough capacitor - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a multilayer feedthrough capacitor used for a noise filter or the like that can effectively reduce noise in a high frequency range by reducing equivalent series inductance (ESL), and particularly relates to information processing equipment and communication equipment. It is suitable for a circuit.
[0002]
[Prior art]
In recent years, most information processing devices and communication devices have been digitized, and the frequency of digital signals handled by these devices has been increasing due to higher information processing capabilities.
Therefore, the noise generated by these devices tends to increase in the high frequency range as well, and many devices are equipped with electronic components to prevent electromagnetic interference and suppress unnecessary voltage fluctuations by taking measures against noise. Is used. A multilayer capacitor is generally employed as an electronic component for countermeasures against noise.
[0003]
However, ESL (equivalent series inductance), which is a parasitic component of the multilayer capacitor, hinders the noise removal effect in the high frequency range, so that the effect becomes insufficient as the operating frequency of the device becomes higher. It has become. In other words, a capacitor having a large ESL, such as a conventional multilayer capacitor, cannot be adapted to the recent increase in frequency.
[0004]
Therefore, in order to take measures against noise in a high frequency range, a multilayer feedthrough capacitor, which is a multilayer feedthrough capacitor, has been commercialized and used as a capacitor with reduced ESL. This will be described below with reference to FIG.
For example, this multilayer feedthrough capacitor 110 used in the form shown in FIG. 7 includes a dielectric sheet 122 having first through conductors 112 drawn on two side surfaces facing each other as shown in FIG. The dielectric sheet 124 on which the second through conductors 114 drawn out on the two side surfaces different from the side surfaces are arranged is a laminated body 120 shown in FIG.
[0005]
Further, as shown in FIGS. 8 and 9, the terminal electrode 132 connected to the first through conductor 112 is formed at the end of the multilayer body 120 so as to be connected to the signal line S, and the terminal connected to the second through conductor 114. The electrode 134 is formed on the side portion of the stacked body 120 so as to be connected to the ground side indicated by GND. 7 and 8, C indicates a capacitor, and ESL indicates an equivalent series inductance.
[0006]
[Problems to be solved by the invention]
However, recent devices have a remarkably high frequency and noise is increasing more and more, while the operating voltage is decreasing due to low power consumption of the devices, and the durability of the devices against noise is decreasing. For this reason, a high noise removal effect in a higher frequency range is required for electronic components for noise countermeasures.
In order to respond to this situation, further reduction of ESL has become an important issue even in multilayer feedthrough capacitors.
In consideration of the above facts, an object of the present invention is to provide a multilayer feedthrough capacitor capable of effectively implementing noise countermeasures in a high frequency range by reducing ESL.
[0007]
[Means for Solving the Problems]
The multilayer feedthrough capacitor according to claim 1 is formed by laminating a plurality of dielectric sheets while at least one dielectric sheet is sandwiched between the first inner conductor and the second inner conductor to form a capacitor body.
A signal terminal electrode connected to the first inner conductor and a ground terminal electrode connected to the second inner conductor are respectively disposed on the side surfaces of the capacitor body,
The second inner conductor is divided into a plurality of parts such that currents flow in opposite directions between adjacent divided parts.
[0008]
According to the multilayer feedthrough capacitor according to claim 1, a capacitor body is formed by laminating a plurality of dielectric sheets while at least one dielectric sheet is sandwiched between the first inner conductor and the second inner conductor. The signal terminal electrode connected to the first inner conductor and the ground terminal electrode connected to the second inner conductor are respectively arranged on the side surfaces of the capacitor body. And the 2nd inner conductor is divided | segmented into plurality in the form where an electric current flows mutually reversely between adjacent division parts.
[0009]
That is, the second inner conductor connected to the ground terminal electrode is divided into a plurality of divided portions, and currents flow in opposite directions between the divided portions adjacent to each other among the plurality of divided portions. Yes.
Therefore, according to the multilayer feedthrough capacitor according to the present invention, the action of canceling out the magnetic field is generated by the currents flowing through the divided portions in the second inner conductor, and this action reduces the inductance of the second inner conductor and reduces the ESL. And noise countermeasures can be implemented more effectively in the high frequency range.
[0010]
According to the multilayer feedthrough capacitor according to claim 2, in addition to the same configuration as the multilayer feedthrough capacitor according to claim 1, the second inner conductor is configured such that current flows in the opposite direction between adjacent divided portions. It is configured to be divided into two.
Therefore, the second inner conductor is divided into two parts, and currents flow in opposite directions from each other among the two divided parts so that the same action as in claim 1 occurs. become.
[0011]
According to the multilayer feedthrough capacitor according to claim 3, in addition to the same configuration as the multilayer feedthrough capacitor according to claim 1 and claim 2, the first internal conductor and the second internal conductor cross each other. The signal terminal electrode and the ground terminal electrode are formed on the side surfaces different from each other.
Therefore, not only the operation similar to that of the first aspect occurs, but also the terminal electrodes are optimally arranged on the side surface of the capacitor body, and the multilayer feedthrough capacitor can be downsized.
[0012]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, a first embodiment of a multilayer feedthrough capacitor according to the present invention will be described with reference to the drawings.
As shown in FIG. 1, the present invention has as its main part a dielectric element body 12 which is a rectangular parallelepiped sintered body obtained by firing a laminate in which a plurality of ceramic green sheets as dielectric sheets are laminated. A multilayer feedthrough capacitor 10 which is an electronic component according to the first embodiment is configured.
[0013]
As shown in FIGS. 2 and 3, an internal electrode 21 extending between the front side and the back side of the dielectric element body 12 in FIG. 3 is disposed at a predetermined height position in the dielectric element body 12. Has been. Further, in the dielectric body 12, below the internal electrode 21 across the ceramic layer 12 </ b> A, which is a sintered ceramic green sheet, between the left side and the right side of the dielectric body 12 in FIG. 3. An internal electrode 22 extending at is disposed.
[0014]
Further, in the dielectric element body 12, an internal electrode extending between the front side and the rear side of the dielectric element body 12 in FIG. 23 is arranged. In addition, an internal electrode 24 extending between the left side and the right side of FIG. 3 of the dielectric body 12 is provided below the internal electrode 23 with the ceramic layer 12 </ b> A in the dielectric body 12. Have been placed.
[0015]
For this reason, the internal electrodes from the internal electrode 21 to the internal electrode 24 are arranged to face each other while being separated by the ceramic layer 12 </ b> A as the dielectric layer in the dielectric element body 12. That is, at least one ceramic layer 12A is sandwiched between the internal electrode 21 and the internal electrode 22, and at least one ceramic layer 12A is sandwiched between the internal electrode 23 and the internal electrode 24. A plurality of ceramic layers 12A are laminated to form a dielectric body 12 that is a capacitor body.
[0016]
Further, the internal electrodes 21 and 23 which are the first internal conductors constitute a path for transmitting signals, and the internal electrodes 22 and 2 which are the second internal conductors extending in a direction intersecting with the internal electrodes 21 and 23, A capacitor is constituted by 24.
These internal electrodes may be arranged not only in four layers but also in a larger number of layers, and the material of these internal electrodes may be, for example, nickel, nickel alloy, copper or copper alloy.
[0017]
Here, as shown in FIG. 3, the internal electrode 22 is constituted by electrode constituent portions 22A and 22B which are a pair of divided portions facing each other, and the internal electrode 24 is also a pair of divided portions facing each other. It is comprised by electrode structure part 24A, 24B which is a part.
The electrode component 22A has two protrusions 42 extending rightward from the wide portion 41 formed wide on the left end side, and the electrode component 22B is formed wide on the right end side. There are two projecting portions 44 extending leftward from the wide portion 43, and the projecting portions 42 and the projecting portions 44 are alternately arranged.
[0018]
Similarly, the electrode component 24A has two protrusions 42 extending in the right direction from the wide portion 41 formed wide on the left end side, and the electrode component 24B is wide on the right end side. Two protrusions 44 extending leftward from the formed wide part 43 are provided, and the protrusions 42 and the protrusions 44 are alternately arranged in the same manner as described above.
[0019]
As described above, the internal electrode 22 has the protruding portions 42 of the electrode component 22A and the protruding portions 44 of the electrode component 22B, which are divided portions adjacent to each other, and the currents are opposite to each other as indicated by arrows in FIG. The internal electrode 24 includes a protruding portion 42 of the electrode configuration portion 24A and a protruding portion 44 of the electrode configuration portion 24B, which are divided portions adjacent to each other. As shown by the arrows in FIG. 3, the structure is divided into two so that currents flow in opposite directions.
[0020]
Further, the pair of signal terminal electrodes 31 and 32 are connected to the both end portions of the internal electrodes 21 and 23 shown in FIGS. 2 and 3, respectively, on the front side surface of the dielectric body 12 shown in FIG. 12B and the rear side surface 12B are disposed respectively. In addition, a pair of ground terminal electrodes 33 and 34 are connected to both ends of the internal electrodes 22 and 24 shown in FIG. 2, respectively, and the left side surface 12C and the right side of the dielectric body 12 shown in FIG. It is arranged on each side surface 12C.
[0021]
As a result, in the present embodiment, as shown in FIG. 1, the signal terminal electrodes 31 and 32 are respectively disposed on the front and back side surfaces 12B of the multilayer feedthrough capacitor 10, and the ground terminals are provided on the left and right side surfaces 12C. By arranging the electrodes 33 and 34 respectively, a four-terminal structure is obtained in which the terminal electrodes 31 to 34 are respectively arranged on the four side surfaces 12B and 12C of the dielectric body 12 that is a hexahedron shape that is a rectangular parallelepiped. Yes.
[0022]
Next, the operation of the multilayer feedthrough capacitor 10 according to the present embodiment will be described.
According to the multilayer feedthrough capacitor 10 according to the present exemplary embodiment, the multilayer feedthrough capacitor 10 is formed so as to extend between the internal electrode 21 and the internal electrode 22 that are formed so as to extend in directions intersecting each other and in a direction that also intersects each other. Each ceramic layer 12 </ b> A is sandwiched between the internal electrode 23 and the internal electrode 24. Further, a single ceramic layer 12 </ b> A is sandwiched between the internal electrode 22 and the internal electrode 23. A plurality of these ceramic layers 12A are laminated to form the dielectric body 12.
[0023]
The signal terminal electrodes 31 and 32 connected to the internal electrodes 21 and 23 and the ground terminal electrodes 33 and 34 connected to the internal electrodes 22 and 24 are arranged on different side surfaces of the dielectric element body 12, respectively. Has been. Further, the internal electrode 22 is divided into two parts in such a manner that currents flow in opposite directions as indicated by arrows in FIG. 3 between the protruding part 42 of the adjacent electrode component 22A and the protruding part 44 of the electrode component 22B. In addition, the internal electrode 24 is divided into two in such a way that currents flow in opposite directions as indicated by arrows in FIG. 3 between the protruding portion 42 of the adjacent electrode component 24A and the protruding portion 44 of the electrode component 24B. Has been.
[0024]
That is, the internal electrodes 22 and 24 connected to the ground terminal electrodes 33 and 34 are divided into two electrode constituent portions 22A and 22B and electrode constituent portions 24A and 24B, respectively. Currents flow in opposite directions.
[0025]
Therefore, according to the multilayer feedthrough capacitor 10 according to the present exemplary embodiment, the currents flowing through the electrode constituting portions 22A and 22B constituting the internal electrode 22 and the inside of the electrode constituting portions 24A and 24B constituting the internal electrode 24 are measured. The flowing currents have an effect of canceling the magnetic field so that magnetic fluxes generated as the current flows cancel each other.
As a result, the parasitic inductance of the internal electrodes 22 and 24 themselves is reduced to reduce ESL, and noise countermeasures can be executed more effectively in the high frequency range.
[0026]
Further, in the present embodiment, the internal electrodes 21 and 23 and the internal electrodes 22 and 24 are formed so as to extend in directions intersecting each other, and the signal terminal electrodes 31 and 32 and the ground terminal electrodes 33 and 34 are formed. Since the dielectric body 12 is disposed on different side surfaces, the terminal electrodes 31 to 34 are optimally disposed on the side surfaces 12B and 12C of the dielectric body 12 to reduce the size of the multilayer feedthrough capacitor 10. It is also possible.
[0027]
Next, a second embodiment of the multilayer feedthrough capacitor according to the present invention will be described with reference to FIG. In addition, the same code | symbol is attached | subjected to the member same as the member demonstrated in 1st Embodiment, and the duplicate description is abbreviate | omitted.
As shown in FIG. 4, in the present embodiment, the internal electrode 22 has two electrode components 22A and 22C extending in the right direction from the left end side of the ceramic layer 12A, and from the right end side of the ceramic layer 12A. It has two electrode components 22B and 22D extending in the left direction. Similarly, the internal electrode 24 has two electrode components 24A and 24C that extend in the right direction from the left end side of the ceramic layer 12A, and two electrode configurations that extend in the left direction from the right end side of the ceramic layer 12A. It has parts 24B and 24D.
[0028]
In other words, in the present embodiment, the internal electrode 22 is divided into four parts in such a way that currents flow in opposite directions in the electrode constituent parts 22A, 22B, 22C, and 22D that are divided parts adjacent to each other. The internal electrode 24 is divided into four parts in such a manner that currents flow in opposite directions in electrode constituent parts 24A, 24B, 24C, 24D which are divided parts adjacent to each other.
[0029]
Therefore, the multilayer feedthrough capacitor 10 according to the present embodiment also has the effect of canceling out the magnetic field by the currents flowing through the divided portions in the internal electrodes 22 and 24, and this effect is the same as in the first embodiment. As a result, the parasitic inductance of the internal electrodes 22 and 24 itself is reduced and ESL is reduced, so that noise countermeasures can be executed more effectively in the high frequency range.
[0030]
Next, a third embodiment of the multilayer feedthrough capacitor according to the present invention will be described with reference to FIG. In addition, the same code | symbol is attached | subjected to the member same as the member demonstrated in 1st Embodiment, and the duplicate description is abbreviate | omitted.
As shown in FIG. 5, in the present embodiment, as one divided portion of the internal electrode 22, an L-shaped electrode component that is formed wide on the left end side of the ceramic layer 12A and extends rightward from this wide portion. 22A is formed. Further, as the other divided portion of the internal electrode 22, an L-shaped electrode configuration portion 22 </ b> B that is formed wide on the right end side of the ceramic layer 12 </ b> A and extends leftward from the wide portion is formed.
[0031]
On the other hand, an L-shaped electrode component 24A is formed as one divided portion of the internal electrode 24 in the same manner as described above, and is formed wide on the left end side of the ceramic layer 12A and extends rightward from the wide portion. Yes. Further, as the other divided portion of the internal electrode 24, an L-shaped electrode configuration portion 24B that is formed wide on the right end side of the ceramic layer 12A and extends leftward from the wide portion is formed.
[0032]
That is, in the present embodiment, the internal electrode 22 is divided into two parts in such a way that currents flow in opposite directions between the electrode constituent part 22A and the electrode constituent part 22B, which are divided parts adjacent to each other. The electrode 24 is divided into two parts in such a manner that currents flow in directions opposite to each other at the electrode constituent part 24A and the electrode constituent part 24B which are divided parts adjacent to each other.
[0033]
Therefore, the multilayer feedthrough capacitor 10 according to the present embodiment also has the effect of canceling out the magnetic field by the currents flowing through the divided portions in the internal electrodes 22 and 24, and this effect is the same as in the first embodiment. Thus, ESL is reduced, and noise countermeasures can be executed more effectively in the high frequency range.
[0034]
Next, ESL of each of the following samples was measured with a network analyzer.
That is, the ESL of a general two-terminal multilayer capacitor as a capacitor, the multilayer feedthrough capacitor 110 of the conventional example, and the multilayer feedthrough capacitor 10 of the present embodiment shown in FIG. 1 were measured.
[0035]
As a result of this measurement, the ESL is 1420 pH in the two-terminal multilayer capacitor, and the ESL is 165 pH in the conventional multilayer feedthrough capacitor 110, whereas in the multilayer feedthrough capacitor 10 of the present embodiment, the ESL is 165 pH. The ESL was 98 pH.
That is, it was confirmed that the multilayer feedthrough capacitor 10 according to the embodiment of the present invention significantly reduces ESL compared to the two-terminal multilayer capacitor and the conventional multilayer feedthrough capacitor 110.
[0036]
As shown in FIG. 6, this ESL is obtained from the equation 2πf ₀ = 1 / √ (ESL · C), where f ₀ is the self-resonant frequency and C is the capacitance.
The dimensions of each sample used here are 3.2 mm in length and 1.6 mm in width, and the capacitance is 1.05 μF for a two-terminal multilayer capacitor. The type capacitor was 1.01 μF, and the multilayer feedthrough capacitor 10 of the present embodiment was 1.03 μF.
[0037]
Furthermore, although the multilayer feedthrough capacitor 10 according to the above embodiment has a structure having four internal electrodes 21 to 24 and four terminal electrodes 31 to 34, the number of layers, the number of internal electrodes, The number of terminal electrodes is not limited to these numbers, and may be larger.
[0038]
【The invention's effect】
ADVANTAGE OF THE INVENTION According to this invention, it becomes possible to provide a multilayer feedthrough capacitor which can reduce ESL and can perform noise countermeasures more effectively in a high frequency range.
[Brief description of the drawings]
FIG. 1 is a perspective view showing a multilayer feedthrough capacitor according to a first embodiment of the present invention.
2 is a cross-sectional view showing the multilayer through-type capacitor according to the first embodiment of the present invention, and corresponds to a cross section taken along line 2-2 in FIG.
FIG. 3 is an exploded perspective view of the multilayer feedthrough capacitor according to the first embodiment of the invention.
FIG. 4 is an exploded perspective view of a multilayer feedthrough capacitor according to a second embodiment of the present invention.
FIG. 5 is an exploded perspective view of a multilayer feedthrough capacitor according to a third embodiment of the present invention.
FIG. 6 is a graph showing impedance characteristics of capacitors.
FIG. 7 is a circuit diagram employing a conventional multilayer feedthrough capacitor.
FIG. 8 is an equivalent circuit diagram of a conventional multilayer feedthrough capacitor.
FIG. 9 is a perspective view showing a multilayer feedthrough capacitor according to a conventional example, showing a relationship between signal flow and grounding.
FIG. 10 is an exploded perspective view showing a multilayer structure of a conventional multilayer feedthrough capacitor.
[Explanation of symbols]
10 Multilayer feedthrough capacitor 12 Dielectric body (capacitor body)
12B, 12C Side surfaces 21, 23 Internal electrode (first internal conductor)
22, 24 Internal electrode (second internal conductor)
31, 32 Signal terminal electrodes 33, 34 Ground terminal electrodes

Claims (3)

A capacitor body is formed by laminating a plurality of dielectric sheets while at least one dielectric sheet is sandwiched between the first inner conductor and the second inner conductor,
A signal terminal electrode connected to the first inner conductor and a ground terminal electrode connected to the second inner conductor are respectively disposed on the side surfaces of the capacitor body,
A multilayer feedthrough capacitor, wherein the second inner conductor is divided into a plurality of parts such that currents flow in opposite directions between adjacent divided parts. 2. The multilayer feedthrough capacitor according to claim 1, wherein the second inner conductor is divided into two so that currents flow in opposite directions between adjacent divided portions. The first inner conductor and the second inner conductor are formed so as to extend in directions intersecting each other, and the signal terminal electrode and the ground terminal electrode are arranged on different side surfaces of the capacitor body. The multilayer feedthrough capacitor according to claim 1 or 2.

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