KR20150059148A - Chip type laminated capacitor - Google Patents

Abstract

A multi-layered capacitor according to an embodiment of the present invention comprises: a ceramic body including a dielectric layer and a first inner electrode and a second inner electrode arranged with the dielectric layer therebetween; and a first outer electrode and a second outer electrode formed respectively on a first surface and a second surface facing each other in the lengthwise direction of the ceramic body, and connected to the first inner electrode and the second inner electrode respectively. One end of the first inner electrode forms a first margin together with the second surface of the ceramic body having the second outer electrode formed thereon, and one end of the second inner electrode forms a second margin together with the second surface of the ceramic body having the first outer electrode formed thereon. The first outer electrode and the second outer electrode respectively have a first band part and a second band part formed by extending on the L-T plane of the ceramic body from the first surface and the second surface of the ceramic body. The first margin, the second margin, the first band part and the second band part satisfy condition (1): 5%<=¦M1/A1-M2/A2¦/ave(M1/A1, M2/A2)<=40% (1), wherein M1 is the length of the first margin, M2 is the length of the second margin, A1 is the length of the first band part, A2 is the length of the second band part, and ave is a function representing an average such that ave(x,y)=(x+y)/2.

Description

[0001] The present invention relates to a chip type laminated capacitor,

The present invention relates to a chip type laminated capacitor which realizes miniaturization and high capacity and reduces acoustic noise.

As electronic products become smaller and more versatile, the chip type laminated capacitors embedded in the above electronic products are also required to be miniaturized and increased in capacity.

In order to miniaturize and increase the chip type stacked capacitor, it is necessary to use a high dielectric constant material such as barium titanate as the ceramic material forming the dielectric layer. When voltage variation occurs in a chip type laminated capacitor having a dielectric layer made of a high dielectric constant material, vibration occurs in the chip type laminated capacitor due to the piezoelectricity of the dielectric layer between the internal electrodes.

The vibration tends to become conspicuous when the dielectric constant of the dielectric layer is higher and the size of the chip is relatively large based on the same capacitance. The vibration is transmitted from the external electrode of the chip type laminated capacitor to the circuit board on which the chip type laminated capacitor is mounted. At this time, the circuit board vibrates and resonance occurs.

That is, if the resonance generated by the vibration of the circuit board is included in the audible frequency range (20 to 20000 Hz), the vibration sound gives an uncomfortable feeling to a person. Such a sound is called acoustic noise.

However, acoustic noise caused by the piezoelectric phenomenon of a multilayer ceramic capacitor using a ferroelectric material is seriously problematic in some electronic devices.

Such a vibration sound is a cause of generation of noise in an electronic device in which the multilayer ceramic capacitor is mounted.

It is an object of the present invention to provide a chip-type laminated capacitor in which the dielectric constant of the dielectric layer is lowered and the acoustic noise is reduced even when the thickness is significantly reduced.

A multilayer capacitor according to an embodiment of the present invention includes: a ceramic body including a dielectric layer and a first internal electrode and a second internal electrode disposed between the dielectric layer; And a first external electrode and a second external electrode respectively formed on first and second surfaces facing each other in the longitudinal direction of the ceramic body and connected to the first internal electrode and the second internal electrode, respectively; Wherein one end of the first internal electrode forms a first margin with a second surface of the ceramic body in which the second external electrode is formed and one end of the second internal electrode is formed of the first external electrode Wherein the first external electrode and the second external electrode each extend on the LT plane of the ceramic body on a first surface and a second surface of the ceramic body, respectively, The first margin and the second margin, and the first band portion and the second band portion may satisfy the following condition (1).

5%? M1 / A1-M2 / A2 / ave (M1 / A1, M2 / A2)? 40%

Here, M1 is the length of the first margin, M2 is the length of the second margin, A1 is the length of the first band portion, and A2 is the length of the second band portion,

ave means ave (x, y) = (x + y) / 2 as a function representing the mean.

According to another aspect of the present invention, there is provided a laminated capacitor comprising: first and second external electrodes formed to cover first and second longitudinal surfaces of a ceramic body; First and second internal electrodes each including first and second capacitance-forming portions overlapping each other with a dielectric layer interposed therebetween, and first and second lead portions connected to the first and second external electrodes; A first margin is formed between the tip of the first capacitance forming portion and the second surface of the ceramic body and a second margin is formed between the tip of the second capacitance forming portion and the first surface of the ceramic body Wherein the first and second external electrodes have first and second band portions formed on an LT plane of the ceramic body, wherein a margin unbalance rate X for the first and second margins is less than a condition ) Can be satisfied.

5%? X =? M1 / A1-M2 / A2 / ave (M1 / A1, M2 / A2)

Here, M1 is the length of the first margin, M2 is the length of the second margin, A1 is the length of the first band portion, and A2 is the length of the second band portion,

ave means ave (x, y) = (x + y) / 2 as a function representing the mean.

According to the chip-type laminated capacitor according to the embodiment of the present invention, the acoustic noise is remarkably reduced in a chip type laminated capacitor having a small dielectric constant and a thickness of a dielectric layer having a low dielectric constant of 3 탆 or less.

1 is a schematic partial cutaway perspective view of a chip type stacked capacitor according to an embodiment of the present invention;
Fig. 2 is a schematic view showing a cutting plane of the line II-II 'in Fig. 1; Fig.
3 is a schematic view showing a cross-section of a line III-III 'of FIG. 1;
FIG. 4 is a schematic perspective view of the chip-type stacked capacitor of FIG. 1 in an exploded state; FIG.
5 is a schematic plan view showing a first embodiment of a laminated state of internal electrodes formed on a dielectric layer;
6 is a schematic plan view showing a second embodiment of a laminated state of internal electrodes formed on a dielectric layer;
7 is a schematic plan view showing a third embodiment of a laminated state of internal electrodes formed on a dielectric layer;
FIG. 8 is a cross-sectional view taken along the WT direction of the internal electrode drawing of FIG. 5, taken along the line VIII-VIII 'of FIG.
FIG. 9 is a cross-sectional view taken along the WT direction of the internal electrode drawing of FIG. 6, taken along line VIII-VIII 'of FIG.
FIG. 10 is a cross-sectional view taken along the WT direction of the internal electrode drawing of FIG. 7, taken along line VIII-VIII 'of FIG.
11 is a schematic cross-sectional view for measuring the length of the band portion of the present invention.

Hereinafter, specific embodiments of the present invention will be described in detail with reference to the drawings. It will be apparent to those skilled in the art that various modifications and variations can be made in the present invention without departing from the spirit or scope of the inventive concept. Other embodiments falling within the scope of the inventive concept may readily be suggested, but are also considered to be within the scope of the present invention.

The same reference numerals are used to designate the same components in the same reference numerals in the drawings of the embodiments.

Chip Type Multilayer Ceramic Capacitors

1 is a schematic partial cut-away perspective view of a chip-type laminated capacitor according to an embodiment of the present invention, FIG. 2 is a schematic view showing a cutting plane II-II 'of FIG. 1, and FIG. 3 is a cross- Line, and FIG. 4 is a schematic perspective view showing the chip-type stacked capacitor of FIG. 1 in an exploded state.

1 to 4, the chip-type stacked capacitor 10 may include a ceramic body 12, first and second external electrodes 14 and 16, and an internal electrode 20.

The ceramic body 12 may be manufactured by applying a conductive paste to form the internal electrode 20 on the ceramic green sheet, laminating the ceramic green sheet on which the internal electrode 20 is formed, and then firing the ceramic green sheet. The ceramic body 12 may be formed by repeatedly stacking a plurality of dielectric layers 40 and internal electrodes 20.

The ceramic body 12 may have a hexahedral shape. Due to the plastic shrinkage of the ceramic powder at the time of chip firing, the ceramic body 12 may have a substantially hexahedral shape although it is not a hexahedron with a perfect straight line.

In order to clearly illustrate the embodiments of the present invention, when the directions of the hexahedron are defined, L, W and T shown in Fig. 1 indicate the longitudinal direction, the width direction and the thickness direction, respectively. Here, the thickness direction can be used in the same concept as the lamination direction in which the dielectric layers are laminated.

The embodiment of Fig. 1 is a chip-type laminated capacitor 10 having a rectangular parallelepiped shape whose longitudinal direction is larger than the width or thickness direction.

As a material for forming the dielectric layer 40, it may be formed of a ceramic powder having a high dielectric constant for high capacity. The ceramic powder is not limited thereto, but for example, barium titanate (BaTiO ₃ ) powder or strontium titanate (SrTiO ₃ ) powder can be used.

In addition, when the grain size after firing is reduced by using a ferroelectric ceramic powder having a small average size, the dielectric constant of the ferroelectric can be reduced. The present invention is not limited by the dielectric constant of the dielectric layer.

In this embodiment, the dielectric layer 40 has a thickness td of 3 m or less, and the average size of the ceramic grains 42 constituting the dielectric layer 40 may be 0.3 m or less. That is, the dielectric layer 40 may be at least ten times the average size of the grains 42 contained in one dielectric layer 40 of the fired chip-type stacked capacitor 10.

Here, the thickness td of the dielectric layer 40 may mean an average thickness of one dielectric layer 40 disposed between the internal electrodes 20.

The thickness of the dielectric layer 40 can be measured by scanning an image of the lengthwise section of the ceramic body 12 with a scanning electron microscope (SEM), as shown in FIG. For example, the length and length direction LT cut at the central portion of the width direction W of the ceramic body 12 may be arbitrarily selected from an image obtained by scanning with a scanning electron microscope (SEM) For the layer 40, the thickness can be measured at 30 points equally spaced in the longitudinal direction and the average value can be measured. The 30 equally spaced points may be measured at a capacitance forming portion, which means an area where the first and second internal electrodes 22 and 24 overlap. Further, by extending the average value measurement to 10 or more dielectric layers 40 and measuring the average value, the thickness of the dielectric layer can be further generalized.

The thickness of the dielectric layer 40 can also be measured in an image scanned by a scanning electron microscope in terms of the width and the thickness direction (W-T) at the center of the longitudinal direction L. [

The center portion of the ceramic body 12 in the width direction W or the longitudinal direction L is located at a center point of the ceramic body 12 in the width direction W or the length direction L, Of the width or 30% of the length.

Meanwhile, the average size of the grain 42 of the dielectric layer 40 can be measured by analyzing a cross-sectional photograph of the dielectric layer extracted by a scanning electron microscope (SEM). For example, the average size of the grain 42 of the dielectric layer 40 may be measured using grain size measurement software that supports an average size standard measurement method of grain as specified in the American Society for Testing and Materials (ASTM) .

In the case of the embodiment of the present invention, by reducing the average size of the grain 42, the ceramic permittivity can be reduced. By setting the thickness of the dielectric layer 40 to 3 m or less, it is possible to stack a large number of the dielectric layers 40 in the same chip size. Therefore, high capacity can be achieved in a miniaturized chip.

The inner electrode 20 may include a first inner electrode 22 and a second inner electrode 24. The first and second inner electrodes 22 and 24 may be formed of a first and a second outer electrodes 22 and 24, (22, 24).

On the other hand, it is possible to reduce the thickness td of the dielectric layer 40 and reduce the average size of the grains 42 in the dielectric layer 40 in order to reduce acoustic noise.

As described above, when the multilayer ceramic capacitor 10 is made low in dielectric constant by reducing the thickness td of the dielectric layer 40 and the average grain size, the acoustic noise is reduced.

However, in the ceramic body 12, the distance between the first and second internal electrodes 22 and 24, that is, the thickness of the dielectric layer 40 is made 3 m or less, The effect of reducing the acoustic noise is remarkably reduced in the multilayer ceramic capacitor 10 in which the number of grains is 10 or more.

This can be seen more clearly from Table 1 below.

NO. Dielectric thickness
(td, 탆) Grain size
(Dc, 占 퐉) td / Dc Vibration sound
(dB) One
4.3 0.68 6.3 43.7 2 0.58 7.4 43.1 3 0.43 10.0 36.3 4 0.26 16.5 33.1 5
2.8
0.59 4.7 43.2 6 0.45 6.2 42.1 7 0.26 10.8 41.0 8 0.16 17.5 40.5 9
1.9

0.60 3.2 43.6 10 0.44 4.5 42.6 11 0.25 7.6 41.7 12 0.16 11.9 40.8

Here, the samples to be tested were prepared as follows.

First, a slurry containing a powder of barium titanate (BaTiO ₃ ) or the like is coated on a carrier film and dried to provide a plurality of ceramic green sheets having a thickness required for various experimental conditions, .

Next, internal electrodes were formed on the green sheet with a conductive paste for a nickel internal electrode by using a screen, and then 370 layers were laminated, and a ceramic laminate was formed by changing the cover layer thickness to 10 to 100 탆.

The ceramic laminated body at 85 ℃ 1000kgf / cm ² Isostatic pressing under pressure conditions.

The pressed ceramic laminate was cut into individual chips, and the cut chips were maintained at 230 DEG C for 60 hours in an atmospheric environment to carry out the binder removal. Then, at 1200 ° C, the internal electrodes were fired in a reducing atmosphere under an oxygen partial pressure of 10 ^-11 atm to 10 ^-10 atm, which is lower than the Ni / NiO equilibrium oxygen partial pressure. The chip size after firing is 3.2 mm x 1.6 mm x 1.6 mm (L x W x T), and the thickness td and the grain size Dc of the dielectric layer are shown in the above table.

Referring to Table 1, it can be seen that when the grain size is reduced and the dielectric constant is lowered under the condition that the dielectric thickness is 4.3 탆 as in the sample 1-4, the magnitude of the vibration noise is remarkably reduced. However, when the dielectric constant is reduced by reducing the grain size under the condition that the dielectric thickness is about 3 탆 or less like the samples 5-12, even when the ratio of td / Dc, that is, the grain size to the dielectric thickness is 1/10 or less, The effect of the reduction is small.

Therefore, when the thickness of the dielectric layer is reduced, it is understood that the effect of reducing the vibration sound can be further increased by adding a separate condition other than the grain size reduction.

According to an embodiment of the present invention, the first and second internal electrodes 22 and 24 may be alternately repeatedly stacked with the dielectric layer 40 therebetween. 2, the cut surface on the LT plane is divided into an active layer 250, an active layer (not shown), and an active layer 250. The active layer 250 includes a first dielectric layer 40 and a second internal electrode 22, 250 and the first internal electrode 22 and the second internal electrode 22 which do not constitute the active layer 250 and the second internal electrode 224 which define the active layer 250, And first and second lead portions 228 and 248 electrically connected to the first and second external electrodes 14 and 16 as a portion of the internal electrode 24, respectively.

Particularly, each of the first and second internal electrodes 22 and 24 forming the active layer 250 and contributing to the formation of the electrostatic capacitance can be defined as the first and second capacitance forming portions 226 and 246, respectively.

Here, when an electric field is applied to the chip-type multilayer ceramic capacitor 10, distortion due to piezoelectricity and electrostrictive property is generated by the capacitance-forming portions 226 and 246 forming the capacitance of the chip-type multilayer ceramic capacitor, The marginal portions except for the first and second elastic members 226 and 246 serve to suppress the distortion.

The first and second external electrodes 14 and 16 may be formed at both longitudinal ends of the rectangular parallelepiped ceramic body 12. The first and second external electrodes 14 and 16 have different polarities and are electrically connected to the first internal electrode 22 and the second internal electrode 24 opposed to each other with the dielectric layer 40 therebetween .

The first and second external electrodes 14 and 16 extend from both ends of the ceramic body 12 in the longitudinal direction when viewed on the LW plane and the LT plane of the ceramic body 12, .

A portion extending inwardly in the longitudinal direction L of the ceramic body 12 at both longitudinal end portions 122 and 124 of the ceramic body 12 is divided into first and second Band portions 142 and 162, respectively. In this case, the widths of the first and second band portions 142 and 162 may be the same or different.

Here, the measurement of the lengths A1 and A2 with respect to the first and second band portions 142 and 162 will be described with reference to FIG.

FIG. 11 is a cross-sectional view schematically showing a length and a thickness direction (L-T) section cut at the central portion in the width direction W of the ceramic body 12 as shown in FIG.

The length A1 of the first band portion 142 of the first external electrode 14 is greater than the length A1 of the upper body portion 12 in the thickness direction of the ceramic body 12, 128 may be defined as a distance from the imaginary line xx 'extending perpendicularly to the thickness direction at the center line C extending from the center points Cp1, Cp2 in the thickness direction to the first band portion 142. [

The second band portion 162 may also be defined as a distance from the imaginary line yy 'extending perpendicularly to the thickness direction at the center line C to the second band portion 162.

The distance between the first band part 142 and the second band part 162 is the innermost point in the longitudinal direction formed in the ceramic body 12 of the first and second band parts 142 and 162.

2 and 4, the first margin M1 formed by the tip ends of the first and second capacitance forming portions 226 and 246 and the end surfaces 122 and 124 of the ceramic body 12, The lengths of the second margins M2 may be different from each other.

The first and second margins M1 and M2 formed by the ends of the first and second capacitance forming portions 226 and 246 and both ends 122 and 124 of the ceramic body 12 By making the lengths different from each other, the vibration caused by the distortion of the chip-type multilayer ceramic capacitor 10 is transmitted to the circuit board, which causes a force imbalance. This imbalance in force suppresses the vibration of the circuit board and reduces the acoustic noise generated in the chip-type multilayer ceramic capacitor 10.

Here, the first and second margins M 1 and M 2 may not exceed 200 μm each for the formation of a capacitor, thereby contributing to formation of a high capacitance.

3 and 4, the third and fourth margins M3 and M4 formed by the widthwise ends of the first and second capacitance forming portions 226 and 246 and the ceramic body 12 are different from each other .

Such a margin imbalance can also reduce the acoustic noise generated in the chip-type multilayer ceramic capacitor 10 for the same reason as the first margin M1 and the second margin M2.

In the chip-type multilayer ceramic capacitor 10 for reducing acoustic noise while realizing miniaturization and high capacity of the present embodiment, the first to fourth margins M1, M2, M3, M4 and the first and second band portions 142 , 162 satisfy the following conditions, it is possible to reduce the acoustic noise in the chip-type laminated capacitor 10, and at the same time, the humidity load NG ratio which can be caused by the absence of the margin can be improved.

First, the unbalance rate X of the first and second margins M1 and M2 can satisfy the following expression.

5%? X =? M1 / A1-M2 / A2 / ave (M1 / A1, M2 / A2)? 40% (One)

Here, M1 is the length of the first margin, M2 is the length of the second margin, A1 is the length of the first band portion, A2 is the length of the second band portion and ave is a function of mean, , y) = x + y / 2.

When X is less than 5%, there is a problem that the acoustic noise, that is, the vibration sound is increased to 40 dB or more. When X is more than 40%, the vibration noise reduction is effective but the humidity load NG rate is generated.

In addition, the margin imbalance rate Y for the third margin M3 and the fourth margin M4 can satisfy the following condition (2).

 5%? Y =? M2-M1 / ave (M1, M2)? 40% (2)

Here, M3 is the length of the third margin, M4 is the length of the fourth margin, and ave is a function which means average. For example, ave (x, y) = x + y / 2.

When Y is less than 5%, there is a problem that the acoustic noise, that is, the vibration sound is increased to 40 dB or more. When Y is more than 40%, the vibration noise reduction is effective but the humidity load NG rate is generated.

In addition, the total margin unbalance rate Z considering the margin unbalance rates X and Y can satisfy the following condition (3).

2.5%? Z = X? Y? 10.5% (3)

Here, the total margin unbalance rate Z may be a variable affecting the acoustic noise reduction.

When Z is less than 2.5%, there is a problem that the acoustic noise, that is, the vibration sound is increased to 40 dB or more. When Z is more than 10.5%, the vibration noise reduction is effective but the humidity load NG rate is generated.

Hereinafter, embodiments of the present invention will be described in more detail with reference to experimental data of Examples and Comparative Examples of the present invention.

Experimental Example

The multilayer ceramic capacitor according to the embodiment and the comparative example of the present invention was produced as follows.

A slurry including a powder such as barium titanate (BaTiO ₃ ) is coated on a carrier film and dried to prepare a plurality of ceramic green sheets having a thickness of 3.9 탆.

Next, a conductive paste for a nickel internal electrode is applied on the ceramic green sheet using a screen such that patterns having asymmetric margins are formed on the ceramic green sheet to form an internal electrode.

370 layers of the above-mentioned ceramic green sheets were laminated, and this laminate was subjected to isostatic pressing under a pressure of 1000 kgf / cm ² at 85 캜. The pressed ceramic laminate was cut into individual chips, and the cut chips were maintained at 230 DEG C for 60 hours in an atmospheric environment to carry out the binder removal.

Then, at 1200 ° C, the internal electrodes were fired in a reducing atmosphere under an oxygen partial pressure of 10 ^-11 atm to 10 ^-10 atm, which is lower than the Ni / NiO equilibrium oxygen partial pressure. The thickness of the dielectric layer after firing was 2.7 mu m, and the average size of the grains of the dielectric layer after firing was And the chip size after firing was 3.2 mm x 1.6 mm x 1.6 mm (L x W x T).

Next, a multilayer ceramic capacitor was manufactured through an external electrode, a plating process, and the like.

Here, the samples of the multilayer ceramic capacitor were manufactured variously according to the asymmetric ratio of the margin portion.

Tables 2 to 4 below are tables comparing the vibration noise and the humidity resistance load NG ratio according to the asymmetry of the margin portion of the cross section of the ceramic body. The vibration noise was directly measured in an anechoic chamber by applying a pulse wave of 3 Vpp to a DC voltage corresponding to ½ of the rated voltage. Then, the moisture load NG rate is shown as 40 ° C, the relative humidity falls below a percentage of the number of samples, the insulation resistance 2.5x0 ⁶ within 100 hours by applying a 25V DC voltage under 95% with respect to 400 sample

No. M1
(탆) M2
(탆) A1
(탆) A2
(탆) X Vibration sound
(dB) Humidity load
NG rate One* 127.6 127.8 582.2 580.6 0.4% 41.3 0.0% 2* 126.0 129.5 578.0 585.4 1.5% 40.8 0.0% 3 123.3 130.7 578.2 583.1 5.0% 34.6 0.0% 4 119.9 136.7 581.6 579.0 13.6% 34.0 0.0% 5 110.9 145.4 583.9 587.1 26.3% 33.3 0.0% 6 103.4 154.0 595.2 590.5 40.0% 32.5 0.0% 7 * 92.0 164.4 580.0 576.2 57.1% 31.6 2.0% 8* 83.4 170.7 574.3 574.9 68.6% 31.1 5.0%

A1: A2: Band portion of the external electrode extending inward in the longitudinal direction at the longitudinal end portion of the ceramic body, X: Marginal unbalance of M1 and M2: Comparative Example, M1 and M2: First and second margins at the LT cross- rate. X = M1 / A1-M2 / A2 / ave (M1 / A1, M2 / A2).

Referring to Table 2, Samples 1, 2, 7 and 8 are comparative examples, and Samples 3 to 7 are examples.

Samples 3 to 7 corresponding to the embodiments of the present invention cause not only a vibration sound having a vibration imbalance rate X of 5% to 40% and a vibration sound of 35dB or less, but also a vibration sound outside the ceramic body 12 It can be seen that there is no phenomenon that defects are generated due to moisture penetration into the electrode.

In the case of Comparative Examples 1 and 2 in which X is less than 5%, there is a problem that acoustic noise, that is, vibration sound increases to 40 dB or more. In the case of Comparative Examples 7 and 8 where X exceeds 40%, vibration sound reduction is effective, .

As a result, the embodiment of the present invention not only remarkably reduces the vibration noise but also reduces the risk of the humidity load NG ratio as compared with the comparative example.

No. M3
(탆) M4
(탆) Y Vibration sound
(dB) Humidity load
NG rate 11 * 102.4 102.6 0.2% 41.4 0.0% 12 * 101.0 103.2 2.2% 40.6 0.0% 13 99.4 104.5 5.0% 34.3 0.0% 14 94.7 109.6 14.6% 33.8 0.0% 15 90.1 114.5 23.9% 33.1 0.0% 16 82.3 123.5 40.0% 32.5 0.0% 17 * 72.5 133.0 58.9% 31.9 3.0% 18 * 63.2 142.1 76.9% 31.0 8.0%

*: Comparative example, M3, M4: third and fourth margins at WT section, Y: marginal unbalance rate of M3 and M4. Y = | M2-M1 | / ave (M1, M2).

Referring to Table 3, Samples 11, 12, 17 and 18 are comparative examples, and Samples 13 to 17 are examples.

Samples 13 to 17 corresponding to the embodiments of the present invention cause not only a vibration sound having a vibration sound of 35 dB or less at a marginal unbalance rate Y of 5% to 40% of M3 and M4, It can be seen that there is no phenomenon that defects are generated due to moisture penetration into the electrode.

In the case of Comparative Examples 11 and 12 where Y is less than 5%, there is a problem that the acoustic noise, that is, the vibration sound is increased to 40 dB or more. In the case of Comparative Examples 17 and 18 where Y is 40% or more, .

As a result, the embodiment of the present invention not only remarkably reduces the vibration noise but also reduces the risk of the humidity load NG ratio as compared with the comparative example.

No. M1
(탆) M2
(탆) M3
(탆) M4
(탆) A1
(탆) A2
(탆) X Y Z Vibration sound
(dB) Humidity load
NG rate 21 * 127.6 127.8 102.4 102.6 583.0 579.4 0.8% 0.2% 0.0% 41.1 0.0% 22 * 123.6 130.4 100.2 104.1 580.2 585.1 4.5% 3.8% 0.2% 40.7 0.0% 23 117.0 138.1 93.5 109.9 579.8 586.4 15.4% 16.1% 2.5% 33.5 0.0% 24 114.5 139.3 89.2 114.8 570.2 575.2 18.7% 25.1% 4.7% 32.7 0.0% 25 110.2 146.1 87.8 117.0 591.4 587.5 28.7% 28.5% 8.2% 32.0 0.0% 26 107.9 146.1 85.3 119.5 578.6 576.4 30.5% 33.4% 10.2% 31.4 0.0% 27 * 100.2 155.2 79.4 125.5 582.4 588.4 42.1% 45.0% 18.9% 31.0 2.0% 28 * 90.5 164.2 70.2 135.0 590.4 592.3 57.6% 63.2% 36.4% 30.3 5.0%

A band portion of the external electrode extending in the longitudinal direction in the longitudinal direction end portion of the ceramic body, X: a band portion of the external electrode extending in the longitudinal direction inward at the longitudinal end portion of the ceramic body, X: a first and a second margin, Marginal unbalance rate of M1 and M2. X = │M1 / A1-M2 / A2│ / ave (M1 / A1, M2 / A2), Y: Margin unbalance rate of M3 and M4. Y = | M2-M1 | / ave (M1, M2), Z: overall margin imbalance rate, Z = X X Y |

The measurement of the lengths (M1, M2, M3, M4) of each of the margins of the samples in Table 4 used the image of the cross-section resulting from polishing the ceramic body in the length and width directions (LW). At this time, the internal electrodes of the two layers overlapping with the thin dielectric layer can be confirmed through the LW plane photograph of one ceramic body.

Referring to Table 4, Samples 21, 22, 27 and 28 are comparative examples, and Samples 23 to 27 are examples.

Samples 23 to 27 corresponding to the embodiments of the present invention cause a low vibration sound having a vibration noise of not more than 35 dB at a total margin unbalance rate, Z of 2.5% to 10%, and also cause external noise from the outside of the ceramic body 12 to the internal electrode It can be seen that there is no phenomenon that defects are generated due to intrusion of moisture.

In the case of Comparative Examples 21 and 22 in which Z is less than 2.5%, there is a problem that the acoustic noise, that is, the vibration sound is increased to 40 dB or more. In the case of Comparative Examples 27 and 28 in which Z exceeds 10.5% .

As a result, the embodiment of the present invention not only remarkably reduces the vibration noise but also reduces the risk of the humidity load NG ratio as compared with the comparative example.

Variation example

FIG. 5 is a schematic plan view showing a first embodiment of a laminated structure of internal electrodes formed on a dielectric layer, FIG. 8 is a cross-sectional view taken along the WT direction of the internal electrode drawing of FIG. 5, VIII 'line and the external electrode is removed.

FIG. 6 is a schematic plan view showing a second embodiment of a laminated state of the internal electrodes formed on the dielectric layer, FIG. 9 is a cross-sectional view taken in the WT direction of the internal electrode drawing of FIG. 6, VIII 'line and the external electrode is removed.

7 is a schematic plan view showing a third embodiment of a laminated state of the internal electrodes formed on the dielectric layer, FIG. 10 is a cross-sectional view taken along the WT direction of the internal electrode drawing of FIG. 7, and FIG. VIII-VIII 'line and the external electrode is removed.

5 and 8 are similar to the embodiment of the present invention in that the widths of the capacitance forming portions 226 and 246 and the lead portions 228 and 248 are the same.

 6 and 9 and the embodiment of FIGS. 7 and 10 are different from the embodiments of FIGS. 5 and 8 in that the first and second capacitive forming portions (first and second internal electrodes 22 and 24) 226, 246 and the first and second lead portions 228, 248 are provided with different widths.

6 and 9, the widths of the first and second capacitance-forming portions 226 and 248 and the widths of the second lead-out portions 228 and 248 are uniformly formed, and the first and second capacitance- The widths of the first and second lead portions 228, 248 are set smaller than the widths of the forming portions 226, 248.

The fifth and sixth margins M5 and M6 formed by the first and second lead portions 228 and 248 and the widthwise ends of the ceramic body 12 on the L-W plane may be formed differently.

The fifth and sixth margins M5 and M6 formed to be different from each other are different from the vibration suppressing force of the first to fourth margins M1, M2, M3, and M4 formed between the capacity- Complementary power can be supplemented.

7 and 10, the widths of the first and second capacitance-forming portions 226 and 248 are the same, but each of the first and second lead portions 228 and 248 has both end portions in the longitudinal direction The width can be continuously decreased. However, the fifth and sixth margins M5 and M6 may be differently formed by differently decreasing the slope continuously.

In this case as well, the fifth and sixth margins M5 and M6, which are formed differently from the embodiments of Figs. 6 and 9, are formed between the capacity forming portion and the outer surface of the ceramic body, (M1, M2, M3, M4) can be compensated.

10: chip type laminated capacitor 14, 16: first and second external electrodes
20: internal electrode 40: dielectric layer
42: Grain
M1, M2, M3, M4, M5 and M6: first to sixth margins
A1, A2: lengths of the first and second band portions

Claims (20)

A ceramic body including a dielectric layer and a first inner electrode and a second inner electrode interposed between the dielectric layers; And
A first outer electrode and a second outer electrode respectively formed on the first and second surfaces of the ceramic body opposite to each other in the longitudinal direction and connected to the first inner electrode and the second inner electrode, respectively; / RTI &gt;
One end of the first internal electrode forms a first margin with the second surface of the ceramic body where the second external electrode is formed,
One end of the second internal electrode forms a second margin with a second surface of the ceramic body where the first external electrode is formed,
Wherein the first external electrode and the second external electrode each have a first band portion and a second band portion which are formed on the first plane and the second plane of the ceramic body and extend on the LT plane of the ceramic body,
The first margin and the second margin, and the first band portion and the second band portion satisfy the following condition (1).
5%? M1 / A1-M2 / A2 / ave (M1 / A1, M2 / A2)? 40%
Here, M1 is the length of the first margin, M2 is the length of the second margin, A1 is the length of the first band portion, and A2 is the length of the second band portion,
ave means ave (x, y) = (x + y) / 2 as a function representing the mean.
The method according to claim 1,
Wherein the dielectric layer is formed to a thickness of 10 mu m or more and 3 mu m or less of an average grain size.
The method according to claim 1,
Wherein each of the first margin and the second margin is 200 mu m or less.
The method according to claim 1,
Wherein the first margin and the second margin have different widths from each other.
The method according to claim 1,
Wherein the first band portion and the second band portion are formed to have different widths.
The method according to claim 1,
Wherein the first and second internal electrodes include a capacitance forming portion which is opposed to and overlapped with the dielectric layer interposed therebetween and a lead-out portion led out to the first and second external electrodes,
The third margin and the fourth margin formed between the both side ends of the capacitance forming portion and the side surface portion of the ceramic body on the LW plane are different from each other,
The margin unbalance rate Y for the third margin and the fourth margin on the WT plane satisfies the following condition (2).
5%? Y =? M3-M4 / ave (M3, M4)? 40% (2)
Here, M3 is the length of the third margin, M4 is the length of the fourth margin,
ave means ave (x, y) = x + y / 2.
The method according to claim 6,
The acoustic noise reduction rate Z considering the margin imbalance rates X and Y satisfies the following condition (3).
2.5%? Z = X? Y? 10.5% (3)
The method according to claim 6,
And the fifth margin and the sixth margin formed between both ends of the lead portion and the side surface portion of the ceramic body on the LW plane are different from each other.
First and second external electrodes formed to cover the longitudinal first and second surfaces of the ceramic body;
First and second internal electrodes each including first and second capacitance-forming portions overlapping each other with a dielectric layer interposed therebetween, and first and second lead portions connected to the first and second external electrodes; / RTI &gt;
A first margin is formed between the tip of the first capacitance forming portion and the second surface of the ceramic body and a second margin is formed between the tip of the second capacitance forming portion and the first surface of the ceramic body,
Wherein the first and second external electrodes have first and second band portions formed on an LT plane of the ceramic body,
Wherein the margin imbalance rate X for the first margin and the second margin satisfies the following condition (4).
5%? X =? M1 / A1-M2 / A2 / ave (M1 / A1, M2 / A2)
Here, M1 is the length of the first margin, M2 is the length of the second margin, A1 is the length of the first band portion, and A2 is the length of the second band portion,
ave means ave (x, y) = (x + y) / 2 as a function representing the mean.
10. The method of claim 9,
Wherein the dielectric layer is formed to a thickness of 10 mu m or more and 3 mu m or less of an average grain size.
10. The method of claim 9,
Wherein each of the first margin and the second margin is 200 mu m or less.
10. The method of claim 9,
Wherein the first margin and the second margin have different widths from each other.
10. The method of claim 9,
Wherein the first band portion and the second band portion have different widths.
10. The method of claim 9,
Wherein the width of the first and second capacitance forming portions and the widths of the first and second lead portions are the same.
10. The method of claim 9,
Wherein the width of the first and second lead portions is the same and smaller than the width of the first and second capacitance forming portions.
10. The method of claim 9,
Wherein the first and second lead portions have a width decreasing continuously in a direction toward the first and second external electrodes.
10. The method of claim 9,
Wherein a third margin and a fourth margin formed between the both side ends of the first and second capacitance forming portions and the side surface portion of the ceramic body on the WT plane are different from each other.
18. The method of claim 17,
The margin unbalance rate Y for the third margin and the fourth margin on the WT plane satisfies the following condition (5): &quot; (5) &quot;
5%? Y =? M3-M4 / ave (M3, M4)? 40% (5)
Here, M3 is the length of the third margin, M4 is the length of the fourth margin,
ave means ave (x, y) = x + y / 2.
19. The method of claim 18,
The acoustic noise reduction rate Z considering the margin imbalance rates X and Y satisfies the following condition (6): &quot; (6) &quot;
2.5%? Z = X? Y? 10.5% (6)
10. The method of claim 9,
Wherein the fifth margin and the sixth margin formed between both ends of the lead portion and the side surface portion of the ceramic body on the LW plane are different from each other.

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