JPH10199746A - Mutilayer ceramic electronic component and its manufacture - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a multilayer ceramic electronic component of high reliability wherein, when the number of layers of internal electrodes is large and the intervals between the electrodes are small, separation and delimitation of the internal electrodes do not occur, and its manufacturing method. SOLUTION: The magnitudes of distortions on both sides of an element 3 which sides are rectangular to the leading-out direction of internal electrodes 2 are X1 and X2. The sum of X1 and X2 on both sides are made smaller than 5%. As a ceramic green sheet for an outer layer sheet, a ceramic green sheet wherein the loadings of binder are made 1.1-1.5 times that of a ceramic green sheet for an electrode sheet is used. The thickness of a conductor pattern for the internal electrode which is to be imparted to the electrode sheet is set in the range of 0.5-2.0μm.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a ceramic electronic component, and more particularly, to a laminated ceramic having a structure in which ceramic layers and internal electrode layers are alternately laminated, and each internal electrode is drawn out to the opposite side for each layer. The present invention relates to an electronic component and a method for manufacturing the same.

[0002]

2. Description of the Related Art For example, a multilayer ceramic capacitor, which is one of the typical multilayer ceramic electronic components, is formed in a ceramic 21 as shown in FIGS. 2 (a) and 2 (b). An internal electrode 2 is provided at both ends of an element (ceramic element) 23 on which a plurality of internal electrodes 22 are disposed.
It is formed by arranging an external electrode 24 that conducts with the second electrode 2.

Incidentally, in the multilayer ceramic capacitor having the above-described structure, in recent years, in order to meet demands for small size and large capacity, the number of laminated internal electrodes 22 is large.
In addition, a multilayer ceramic capacitor having a small distance (inter-electrode distance) between adjacent internal electrodes 22 via the ceramic layer 21a is manufactured.

However, when the number of stacked internal electrodes 22 is increased and the distance between the electrodes is reduced, the element 23 is distorted due to the difference in shrinkage between the ceramic and the internal electrodes during firing, and the internal electrodes 22 are peeled off. Or delamination occurs, and it becomes impossible to obtain desired characteristics.

[0005] Such peeling or delamination of the internal electrodes tends to occur particularly when the number of stacked internal electrodes 22 is 100 or more and the distance between the electrodes is about 5 µm or less.
When the number of stacked internal electrodes 22 is 300 or more and / or the distance between the electrodes is about 3 μm or less, the tendency becomes more remarkable.

The present invention solves the above-mentioned problems. Even when the number of laminated internal electrodes is large and the distance between the electrodes is small, peeling and delamination of the internal electrodes do not occur, and a highly reliable laminated layer is formed. An object of the present invention is to provide a ceramic electronic component and a method for manufacturing the same.

[0007]

Means for Solving the Problems In order to achieve the above object, a multilayer ceramic electronic component according to the present invention is provided with an element having a structure in which ceramic layers and internal electrodes are alternately laminated.
A multilayer ceramic electronic component provided with an external electrode that conducts with the internal electrode, wherein the element has a minimum distortion in a direction parallel to a surface of the internal electrode. It is characterized in that the difference in element width between the central part in the thickness direction and the upper and lower outer layer parts where the element width is maximum is less than 5%.

[0008] In the multilayer ceramic electronic component, at the time of firing, the portion where the internal electrode is provided, that is, the strain (shrinkage) in the central portion in the element thickness direction becomes the largest, and the internal electrode is provided in the exterior portions on the upper and lower surfaces. Distortion (shrinkage) is minimized. Then, a large stress is applied to the element due to the difference in distortion, and peeling of the internal electrode and delamination occur. According to the first aspect of the present invention, the magnitude of the strain in the direction parallel to the surface of the internal electrode of the element, that is, the difference between the element width of the maximum part and the element width of the minimum part is 5% between the central part in the element thickness direction and the upper and lower outer layer parts. Since it is less than the above, peeling of the internal electrode and occurrence of delamination can be reliably suppressed, and a multilayer ceramic electronic component having desired characteristics can be obtained.

The multilayer ceramic electronic component according to the present invention is a multilayer ceramic electronic component in which an element having a structure in which ceramic layers and internal electrodes are alternately laminated is provided with external electrodes that are electrically connected to the internal electrodes. Further, the magnitude of the strain on the side surface of the element in the direction orthogonal to the internal electrode drawing direction is less than 5% in total on both side surfaces.

[0010] In the multilayer ceramic electronic component of the present invention (claim 2), "the magnitude of the strain on the side surface in the direction perpendicular to the direction in which the internal electrode is drawn" refers to the internal electrode 2 as shown in FIG. When the element 3 is cut in a direction perpendicular to the direction in which the element 3 is pulled out, the ends A of the upper and lower outer layer portions (portions with the least shrinkage distortion) 5 on the cut surface and the most shrinkage distortion at the center of the side surface 3a of the element 3 This is a concept meaning the size of the horizontal distances X1 and X2 of the large portion B (that is, the depth of the depression in the side surface 3a).

[0011] The phrase "the magnitude of the distortion is set to less than 5% in total on both side surfaces" means that the magnitude of the distortion is determined by the element 3 in FIG.
Means less than 5% of the width W, which means that the condition of the following equation (1) is satisfied. {(X1 + X2) / W} × 100 <5 (1)

As described above, by setting the magnitude of the strain on the side surface of the element in the direction perpendicular to the internal electrode drawing direction to be less than 5% in total on both side surfaces, peeling of the internal electrode and delamination are prevented. Generation can be suppressed reliably, and a multilayer ceramic electronic component having desired characteristics can be obtained.

Further, the multilayer ceramic electronic component of the present invention is characterized in that the magnitude of the strain on the side is substantially the same on both sides.

By making the magnitude of the strain substantially the same on both side surfaces, it is possible to suppress the occurrence of bias in the manner of applying stress to the internal electrodes and the like, and to efficiently remove the internal electrodes and cause delamination. It becomes possible to suppress.

Further, the multilayer ceramic electronic component of the present invention is characterized in that the number of stacked internal electrodes is 100 or more, and the distance between adjacent internal electrodes via the ceramic layer is 5 μm or less.

When the number of laminated internal electrodes is 100 or more and the distance between adjacent internal electrodes via the ceramic layer is 5 μm or less, peeling and delamination of the internal electrodes tend to occur. By applying the present invention to the present invention, peeling of the internal electrodes and occurrence of delamination can be reliably suppressed, and a multilayer ceramic electronic component having desired characteristics can be obtained.

When the number of stacked internal electrodes is 300 or more and / or the distance between the electrodes is 3 μm or less, peeling and delamination of the internal electrodes are particularly likely to occur, so that it is more significant to apply the present invention. become.

Further, the method for manufacturing a multilayer ceramic electronic component of the present invention comprises the steps of: laminating a plurality of ceramic green sheets (electrode-provided sheets) provided with a conductor pattern for internal electrodes; The multilayer ceramic electronic device according to any one of claims 1 to 3, wherein a ceramic green sheet (outer layer sheet) not provided with a conductor pattern is laminated and pressed to form a laminate, and the laminate is fired. A method for producing a part, wherein the binder content of the ceramic green sheet for the outer layer sheet is 1.1 to 1.0 of the binder content of the ceramic green sheet for the electrode-added sheet.
It is characterized by using a ceramic green sheet in a range of 1.5 times.

As the ceramic green sheet for the outer layer sheet, the binder content is 1.1 to 1.1 times the binder content of the ceramic green sheet for the electrode-added sheet.
By using the ceramic green sheet in the range of 5 times, the amount of shrinkage of the outer layer sheet during firing is increased,
It becomes possible to approach the contraction amount of the electrode application sheet,
By suppressing the occurrence of distortion, it becomes possible to efficiently manufacture a multilayer ceramic electronic component without peeling or delamination of the internal electrode.

When the amount of the binder added is less than 1.1 times, the effect of increasing the shrinkage of the outer layer sheet becomes insufficient, and when the amount exceeds 1.5 times, It is not preferable because the amount of shrinkage becomes too large.

Further, the method for manufacturing a multilayer ceramic electronic component of the present invention comprises the steps of: laminating a plurality of ceramic green sheets (electrode-provided sheets) provided with a conductor pattern for internal electrodes; The multilayer ceramic electronic device according to any one of claims 1 to 3, wherein a ceramic green sheet (outer layer sheet) not provided with a conductor pattern is laminated and pressed to form a laminate, and the laminate is fired. In a method of manufacturing a component, the thickness of a conductor pattern for an internal electrode applied to the electrode application sheet is in a range such that the thickness of an internal electrode formed after firing is 0.5 to 2.0 μm. It is characterized by:

By setting the thickness of the conductor pattern for the internal electrode to be applied to the electrode application sheet in a range such that the thickness of the internal electrode formed after firing is 0.5 to 2.0 μm, By reducing the amount of shrinkage during firing,
It becomes possible to approach the contraction amount of the outer layer sheet. Therefore, it is possible to efficiently produce a multilayer ceramic electronic component free from internal electrode peeling and delamination while suppressing the occurrence of distortion.

If the thickness of the internal electrode formed after firing is less than 0.5 μm, desired characteristics cannot be obtained due to electrode breakage and the like. This is not preferable because the amount of shrinkage at the time cannot be sufficiently reduced.

[0024]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, embodiments of the present invention will be shown and the features thereof will be described in more detail. Here, a multilayer ceramic capacitor will be described as an example of the multilayer ceramic electronic component.

First, for example, barium titanate-based ceramic raw material powder is dispersed in a dispersion medium containing a binder or the like to form a slurry, and then the slurry is formed into a sheet to obtain a ceramic green sheet having a thickness of 7 μm.

On the ceramic green sheet, for example, a conductive paste is printed in a predetermined pattern and dried, so that a ceramic green sheet (electrode-attached sheet) on which a plurality of electrode patterns are provided (mother sheet) To form

Also, after the ceramic raw material powder is dispersed in a dispersion medium having a higher binder content than that of the above-mentioned electrode-provided sheet to form a slurry, the slurry is formed into a sheet, and a ceramic green sheet (outer layer) having a thickness of 20 μm is formed. Sheet). The binder content of this outer layer sheet is 1.1 to 1.0 of the binder content of the above electrode-added sheet.
1.5 times. This is not the case when manufacturing the multilayer ceramic electronic component of the comparative example in which the distortion exceeds the range of the present invention.

Then, a plurality of the above-mentioned electrode-attached sheets are stacked, and an outer layer sheet having no electrode pattern is stacked on both the upper and lower surfaces thereof, and pressed.
This is cut to cut out each unfired element.

Next, the unfired device is fired under predetermined conditions to form external electrodes, thereby obtaining the external electrodes shown in FIGS.
(b) As shown in FIG.
A multilayer ceramic capacitor having a structure in which external electrodes 4 (FIG. 1 (a)) electrically connected to the internal electrodes 2 are provided on both ends of the element 3 provided with.

In this embodiment, the overall strain (ie, the total value of the strains X1 and X2 in FIG. 1B) is changed by adjusting the binder content in the outer layer sheet. The occurrence rate (defective rate) of defects due to peeling of the internal electrodes and occurrence of delamination was examined (n
= 100). In this embodiment, the magnitudes X1 and X2 (FIG. 1) of the strain on the side surfaces 3a on both sides of the element 3 are set to be substantially the same.

Table 1 shows the relationship between the magnitude of the entire strain and the defect rate due to peeling of the internal electrodes and occurrence of delamination.

[0032]

[Table 1]

According to Table 1, when the total distortion X is less than 5%, the defect rate is 0%, but when the total distortion is 5%, the defect rate becomes 1%, and further, the distortion X is 7.5%. , 10%
It can be seen that as the ratio increases, the defect rate also increases to 35% and 83%. Therefore, in order to suppress the failure rate due to the peeling of the internal electrodes and the occurrence of delamination, it is desirable that the overall distortion be less than 5%.

In the above embodiment, the case where the distortions X1 and X2 (FIG. 1) on both sides of the element 3 are made substantially the same has been described.
When there is a large difference between the two, the ratio of the defect rate with respect to the magnitude X of the entire distortion becomes larger than that in the case where the distortions X1 and X2 (FIG. 1) on both side surfaces are substantially the same.

For example, when the overall distortion is 5% and X1 is 1.5 times X2,
The defect rate is 10% (about 10% when X1 and X2 are the same).
X), when the overall distortion is 5% and X1 is 2.0 times X2,
The defect rate is 18% (about 18% when X1 and X2 are the same).
X), when the overall distortion is 5% and X1 is 3.0 times X2,
The defective rate is 55% (about 55 times that when X1 and X2 are the same)
Becomes

Therefore, in order to efficiently reduce the defective rate due to peeling or delamination of the internal electrodes, the magnitude of the entire strain should be less than 5% and the magnitude of the strain on both side surfaces should be as close as possible. Is desirable.

In the above embodiment, by increasing the binder content of the ceramic green sheet for the outer layer sheet, the amount of shrinkage of the outer layer sheet during firing is increased to approach the amount of shrinkage of the electrode-added sheet. The case where the strain X of the electrode-providing sheet is set to less than 5% has been described. By approaching the amount, it is possible to suppress the overall distortion X to less than 5%.

It should be noted that the present invention is not limited to the above embodiment, but relates to the specific dimensions and shape of the element, the type of ceramic constituting the element, the number of laminated internal electrodes, and the like. It is possible to add various applications and modifications within the above.

[0039]

As described above, in the multilayer ceramic electronic component of the present invention (claim 1), the magnitude of the distortion of the element in the direction parallel to the surface of the internal electrode is reduced by the element having the minimum element width. Since the difference in element width between the central part in the thickness direction and the upper and lower outer layers where the element width is maximized is less than 5%, the stress applied to the element is reduced and the internal electrodes are peeled off or delaminated. Can be reliably suppressed, and a multilayer ceramic electronic component having desired characteristics can be obtained.

Further, in the multilayer ceramic electronic component of the present invention (claim 2), the magnitude of the strain on the side surface of the element in the direction orthogonal to the internal electrode drawing direction is 5% in total on both side surfaces.
It is possible to prevent peeling of the internal electrode and occurrence of delamination,
A multilayer ceramic electronic component having desired characteristics can be obtained.

When the magnitude of the strain is substantially the same on both sides, the occurrence of bias in the manner in which stress is applied to the internal electrodes and the like is reduced, and peeling and delamination of the internal electrodes are efficiently generated. Can be suppressed.

Further, the number of laminated internal electrodes is 100 or more, and the distance between adjacent internal electrodes via the ceramic layer is 5 μm.
m or less, there is a tendency that peeling and delamination of the internal electrode tend to occur, but in that case, by applying the present invention, it is possible to reliably suppress peeling and delamination of the internal electrode. Thus, a multilayer ceramic electronic component having desired characteristics can be obtained.

In the method for manufacturing a multilayer ceramic electronic component according to the present invention (claim 5), the binder content of the ceramic green sheet for the outer layer sheet is 1.
Since the ceramic green sheet in the range of 1 to 1.5 times is used, it is possible to increase the amount of shrinkage of the outer layer sheet during firing, and to approach the amount of shrinkage of the electrode-provided sheet, thereby causing distortion. Thus, a multilayer ceramic electronic component free of peeling of the internal electrode and delamination can be efficiently manufactured.

In the method of manufacturing a multilayer ceramic electronic component according to the present invention (claim 6), the thickness of the internal electrode conductor pattern applied to the electrode application sheet is set to 0. Since the thickness is in the range of 5 to 2.0 μm, it is possible to reduce the amount of contraction of the electrode-provided sheet during firing and approach the amount of contraction of the outer layer sheet. Therefore, it is possible to efficiently manufacture a multilayer ceramic electronic component free from internal electrode peeling and delamination while suppressing the occurrence of distortion.

[Brief description of the drawings]

FIG. 1 is a view showing a multilayer ceramic electronic component (multilayer ceramic capacitor) according to an embodiment of the present invention, wherein (a) is a perspective view and (b) is a cross-sectional view taken along line AA of (a). .

2A and 2B are views showing a conventional multilayer ceramic electronic component (multilayer ceramic capacitor), wherein FIG. 2A is a perspective view, and FIG.
It is a BB sectional view taken on the line of (a).

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 Ceramic 1a Ceramic layer 2 Internal electrode 3 Element 3a Side surface of element 4 External electrode X1, X2 Distortion on each side surface 5 Upper and lower outer layer portions (portion where shrinkage distortion is least) A Ends on both sides of outer layer portion B Element center Part with the largest shrinkage strain

Claims (6)

[Claims] 1. A multilayer ceramic electronic component comprising: an element having a structure in which ceramic layers and internal electrodes are alternately stacked; and an external electrode that is electrically connected to the internal electrode. The magnitude of the strain in the direction parallel to the surface of the electrode is set such that the difference in element width between the central part in the element thickness direction where the element width is minimum and the upper and lower outer layer parts where the element width is maximum is less than 5%. A multilayer ceramic electronic component having a size. 2. A multilayer ceramic electronic component comprising: an element having a structure in which ceramic layers and internal electrodes are alternately stacked; and an external electrode that is electrically connected to the internal electrode. A multilayer ceramic electronic component, wherein the magnitude of strain on the side surface in the direction perpendicular to the electrode lead-out direction is less than 5% in total on both side surfaces. 3. The multilayer ceramic electronic component according to claim 2, wherein the magnitude of the strain on the side surface is substantially the same on both side surfaces. 4. The multilayer ceramic according to claim 1, wherein the number of laminated internal electrodes is 100 or more, and the distance between adjacent internal electrodes via the ceramic layer is 5 μm or less. Electronic components. 5. A ceramic green sheet (an outer layer) to which a plurality of ceramic green sheets (electrode-provided sheets) provided with conductor patterns for internal electrodes are laminated, and the upper and lower surfaces of which are not provided with conductor patterns for internal electrodes. 4. The method for producing a multilayer ceramic electronic component according to any one of claims 1 to 3, wherein a laminate is formed by laminating and pressing the laminate, and the laminate is fired. As a ceramic green sheet for
A method for producing a multilayer ceramic electronic component, wherein a ceramic green sheet having a binder content in a range of 1.1 to 1.5 times the binder content of the ceramic green sheet for an electrode-added sheet is used. 6. A plurality of ceramic green sheets (electrode-provided sheets) provided with conductor patterns for internal electrodes, and ceramic green sheets (outer layers) not provided with conductor patterns for internal electrodes on both upper and lower surfaces. The method for manufacturing a multilayer ceramic electronic component according to any one of claims 1 to 3, wherein the laminate is formed by laminating and pressing a sheet, and the laminate is fired. The thickness of the conductor pattern for the internal electrode applied to the sheet is adjusted so that the internal electrode formed after firing has a thickness of 0.
A method for producing a multilayer ceramic electronic component, characterized in that the thickness is in the range of 5 to 2.0 μm.