JP4048888B2 - Manufacturing method of multilayer ceramic electronic component and gravure printing plate used therefor - Google Patents

Description

【００２８】
表１に示すように、２μｍ未満では、セラミックグリーンシートに直径１μｍ以上の穴が存在した。したがって、この結果から、セラミックグリーンシートにダメージ部が生じないようにするためには、グラビア印刷版において凹部１の開口縁に曲面部を設け、曲面部の所定曲率半径Ｒを２μｍ以上にすればよいことが分かる。
【００２９】
また、曲面部の所定曲率半径Ｒが大きくなるほど、導電ペーストの塗布厚が薄くなっている。これは、土手部の天面の幅を一定にしているため、曲面部の所定曲率半径Ｒが大きくなるほど、土手部の幅が太くなり、凹部が小さくなるので、導電ペーストの充填体積が減少するからである。そして、表１の結果から、凹部の曲面部の所定曲率半径Ｒは１０μｍ以下にすることが良いことが分かる。凹部の曲面部の所定曲率半径Ｒを１５μｍ以上になると、塗布厚が薄くなる度合いが許容範囲を超えることになる。逆に、一定の幅の土手部において、所定曲率半径Ｒを大きくした場合においても、土手部天面が曲面部になっていくことから土手部天面の幅が小さくなり、印刷パターン１１にセラミックグリーンシートが入り込んで、結果的に導電ペーストの厚みが薄くなる。
【００３０】
次に、第２の実施形態に係るグラビア印刷版の構成について、図３を参照して説明する。
図３はグラビア印刷版の部分拡大平面図である。
図３に示したグラビア印刷版は、凹部の開口縁に形成する曲面部４ａ〜４ｄの所定曲率半径Ｒがそれぞれに異なるものであり、他の構成は図１に示したグラビア印刷版と同じである。
【００３１】
例えば、図３に示した例では、グラビア印刷版の土手部２が印刷方向に対して、平行、垂直であり、印刷方向に垂直に形成された曲面部４ａ，４ｃは所定曲率半径Ｒを大きくし、印刷方向に平行に形成された曲面部４ｂ，４ｄは、曲面部４ａ，４ｃに比べて、所定曲率半径Ｒを小さくすることができる。これは、印刷方向に平行に形成された曲面部４ｂ，４ｄは、凹部１の導電ペーストを転写する際に、常時、曲面部４ｂ，４ｄの一部がセラミックグリーンシートに接触しているのに対し、印刷方向に垂直に形成された曲面部４ａ，４ｃは、凹部１が導電ペーストを転写する最初、および最後のみに押圧が掛かるため、一度にセラミックグリーンシートに掛かる押圧量が大きくなる。よって、印刷方向に略平行な領域の曲面部４ｂ，４ｄは、印刷方向に略垂直な領域の曲面部４ａ，４ｃに比べ、セラミックグリーンシートに与える押圧による影響が低くくなり、所定曲率半径Ｒを小さくすることができる。
【００３２】
なお、前述の実施形態では、凹部が印刷方向に平行、垂直に配列形成された場合を示したが、印刷方向に対応して、所定曲率半径を調整すれば、同様の効果が得られる。
【００３３】
また、前述の実施形態では、凹部を形成した後に、さらに化学反応を用いたエッチングで曲面部４を形成しているが、これに限るものではなく、例えば、凹部を形成する際に、エッチング時間を制御することによって曲面部を有する凹部を得ることができる。
【００３４】
さらに、前述の実施形態では、グラビア印刷で内部電極用パターンを形成する際について説明したが、これに限るものではなく、例えば、セラミックグリーンシート上の内部電極以外の部分に段差吸収用の誘電体パターンをグラビア印刷する際にも本願発明は適用でき、要はセラミックグリーンシート上に所定のパターンをグラビア印刷する方法全てに適用することができる。
【００３５】
【発明の効果】
この発明によれば、多数の凹部の開口縁について所定曲率半径Ｒを有する曲面とし、この所定曲率半径Ｒを２μｍ≦Ｒ＜１５μｍとしているため、薄いセラミックグリーンシートにダメージ部を生じることなく、導電ペーストや誘電体ペースト等の転写物を転写することができ、積層セラミック電子部品を製造した場合、ダメージ部に起因するシートアタック等の問題を低減することができる。
【００３６】
また、転写物として導電ペーストを用い、内部電極用パターンを印刷した場合、ダメージ部分に起因する短絡不良や絶縁抵抗不良を防止することができる。また、転写物の塗布厚をそれほど薄くすることもないため、内部電極切れ等の問題が生じない。
【００３７】
【図面の簡単な説明】
【図１】第１の実施形態に係るグラビア印刷版の部分拡大平面図、部分拡大側面図
【図２】第１の実施形態に係るグラビア印刷工程の印刷部の拡大図
【図３】第２の実施形態に係るグラビア印刷版の部分拡大平面図
【図４】積層セラミックコンデンサの側面断面図
【図５】従来のグラビア印刷版の平面図、部分拡大平面図、および部分拡大側面図
【図６】内部電極用パターン印刷（グラビア印刷）工程の概念図
【図７】従来のグラビア印刷工程の印刷部の拡大図
【符号の説明】
５３−グラビア印刷版
１−グラビア印刷版１０に設けられた凹部
２−グラビア印刷版１０に設けられた凹部１を隔てる土手部
３−凹部１の開口縁を構成する稜線部
４，４ａ〜４ｄ−凹部１の開口縁に設けられた曲面部
２０−積層セラミックコンデンサ
２１−誘電体層
２２−内部電極
２３−素体
２４−外部電極
３１−導電ペースト
３２−セラミックグリーンシート
３３−セラミックグリーンシート３２に発生したダメージ部
５１−キャリアフィルム
５２−テンションロール
５４−圧胴
５５−導電ペースト槽
５６−ドクターブレード
５７−乾燥炉[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a method for manufacturing a multilayer ceramic electronic component that is gravure-printed on a ceramic green sheet that constitutes the multilayer ceramic electronic component, and a gravure printing plate used therefor.
[0002]
[Prior art]
A configuration of a multilayer ceramic capacitor which is an example of a general multilayer ceramic electronic component will be described with reference to FIG.
FIG. 4 is a side sectional view of the multilayer ceramic capacitor. 20 is a multilayer ceramic capacitor, 21 is a dielectric layer, 22 is an internal electrode, 23 is an element body, and 24 is an external electrode.
[0003]
As shown in FIG. 4, a multilayer ceramic capacitor 20 that is a multilayer ceramic electronic component includes a large number of dielectric layers 21, and internal electrodes that are arranged between the dielectric layers 21 and are alternately exposed on side surfaces that face each other. The element body 23 is composed of 22 and a pair of external electrodes 24 provided on opposite sides of the element body 23.
[0004]
The dielectric layer 21 and the internal electrode 22 of the conventional multilayer ceramic capacitor 20 are formed as follows. First, the ceramic green sheet used as the dielectric material layer 21 is formed by apply | coating the dielectric material slurry which consists of dielectric material powder, an organic binder, etc. on a carrier film. Next, an internal electrode pattern is formed by printing a conductive paste on the surface of the ceramic green sheet. The ceramic green sheet on which the internal electrode pattern is formed in such a process is peeled off from the carrier film, and a predetermined number of sheets are laminated, and pressed to be integrated to form a laminated body. Thereafter, the laminated body is cut in the thickness direction, sintered to form individual element bodies 23, and a pair of external electrodes 24 are applied and baked on the end faces of the element bodies 23 so as to be electrically connected to the internal electrodes 22. Thus, the multilayer ceramic capacitor 20 is formed.
[0005]
At present, in such multilayer ceramic electronic components, miniaturization and large capacity are progressing, and accordingly, the dielectric and internal electrodes are being made thinner. In particular, the dielectric is thinned to a thickness of 2 to 3 μm or less, and the thickness of the internal electrode is required to be as thin as about 1 μm. For this reason, there is a need for a technique for thinly printing the internal electrode pattern, and a gravure printing method is used as this printing method.
[0006]
A conventional gravure printing plate used for gravure printing has a shape shown in FIG. 5 (see, for example, Patent Document 1).
[0007]
5A is a partially enlarged view of the gravure printing plate, FIG. 5B is a partially enlarged view of the printing pattern, and FIG. 5C is an enlarged sectional view.
[0008]
The gravure printing plate 53 has a cylindrical shape, and has a plurality of printing patterns 11 shown in FIG. The print pattern 11 is configured by a collection of a large number of concave portions 1, and the collective shape of the large number of concave portions 1 is the outer shape of the print pattern 11.
[0009]
Such a gravure printing plate 53 is manufactured by the following method.
A resist material is formed in a lattice shape on the base material of the gravure printing plate 53 made of a columnar metal, except for portions corresponding to a large number of recesses 1. Next, the resist material is not dissolved, and only the metal of the gravure printing plate 53 is etched by chemical treatment to form a large number of recesses 1. Thereafter, by removing the resist material, a plurality of print patterns 11 including a large number of concave portions 1 and bank portions 2 are formed.
[0010]
Also, a method of forming a plurality of printing patterns 11 composed of a large number of concave portions 1 and bank portions 2 by engraving a large number of concave portions 1 with a laser on the base material of the gravure printing plate 53 and then performing surface treatment by barrel polishing. Proposed.
[0011]
The gravure printing plate 53 manufactured by such a method is used in a process of forming an internal electrode pattern of a multilayer ceramic electronic component as shown in FIG. FIG. 6 is a conceptual diagram of a gravure printing process of an internal electrode pattern.
[0012]
As shown in FIG. 6, the carrier film 51 on which the ceramic green sheet is formed reaches the gravure printing plate 53 through a plurality of tension rolls 52. The gravure printing plate 53 is formed with a recess 1 for filling the conductive paste 31 in a predetermined shape. A part of the gravure printing plate 53 is immersed in the conductive paste 31 stored in the conductive paste tank 55, and the conductive paste 31 is supplied to the concave portion 1 of the gravure printing plate 53 while rotating. The supplied conductive paste 31 is scraped off by the doctor blade 56, and only the necessary amount is filled in the recess 1. The impression cylinder 54 rotates in synchronization with the gravure printing plate 53. Further, the gravure printing plate 53 and the impression cylinder 54 are pressed in the direction in which they are pressed against each other. When the carrier film 51 on which the ceramic green sheet is formed passes between the gravure printing plate 53 and the impression cylinder 54, the conductive paste 31 filled in the concave portion 1 of the gravure printing plate 53 by this pressing becomes the surface of the ceramic green sheet. Is pressed and transferred. The transferred conductive paste 31 is dried by passing through the drying furnace 57.
[0013]
[Patent Document 1]
JP-A-9-129504 [0014]
[Problems to be solved by the invention]
However, in a multilayer ceramic electronic component having an internal electrode formed using such a conventional gravure printing plate, a short circuit failure or an insulation resistance failure may occur. This is caused by the progress of thinning of the dielectric, but as a result of further investigation of the cause, it has been found that the cause of these defects exists in the gravure printing plate.
[0015]
That is, when a large number of recesses 1 are formed by etching, the bank portion 2 is normally formed at the position of the resist material, so that the opening edge of the recess 1 is formed as shown in FIG. The ridgeline portion 3, that is, the ridgeline portion 3 on the top surface of the bank portion 2 has a cornered shape.
[0016]
Further, even when the concave portion 1 is engraved with a laser and the surface thereof is barrel-polished, since the base material of the gravure printing plate is a metal and the concave portion 1 is minute, the ridge line portion 3 cannot be completely polished, and the ridge line portion 3 The corners are easy to remain. Further, if the polishing time is long, the corners of the ridge line portion 3 are polished, but the bank portion 2 becomes small, the ceramic green sheet enters the print pattern 11, and as a result, the thickness of the conductive paste becomes thin.
[0017]
When the conductive paste 31 is transferred to the ceramic green sheet 32 using such a gravure printing plate 53 having the bank portion 2, as shown in FIG. 7, the bank portion 2 is separated from the moment when it contacts the ceramic green sheet 32. In particular, pressure is applied to the ridgeline portion 3 immediately before. For this reason, a damaged portion 33 such as a small scratch occurs in a portion of the ceramic green sheet 32 to which pressure is locally applied. Due to the damaged portion 33, the conductive paste 31 enters the damaged portion 33, or the solvent contained in the conductive paste 31 enters the damaged portion 33 to erode the ceramic green sheet 32.
[0018]
When a multilayer ceramic electronic component is manufactured using a ceramic green sheet in such a state, there is a problem that a short-circuit failure in which internal electrodes are short-circuited or a dielectric whose characteristics are changed due to erosion is generated, resulting in an insulation resistance failure. Arise. Such a problem is not a problem when the ceramic green sheet serving as a dielectric is about 10 μm because the damaged portion 33 is minute, but when the thickness is reduced to 2 to 3 μm, the damaged portion 33 cannot be ignored. It is caused to become.
[0019]
An object of the present invention is to provide a gravure printing plate capable of transferring a transferred material without forming minute damage portions on the ceramic green sheet 32 and a method for manufacturing a multilayer ceramic electronic component formed using the gravure printing plate.
[0020]
[Means for Solving the Problems]
In the present invention, a predetermined pattern is formed by assembling a plurality of concave portions each surrounded by a curved surface having a radius of curvature R within a range of 2 μm ≦ R <15 μm and filled with a transfer product. Using the gravure printing plate, the ceramic green sheet to which the transferred material is transferred is laminated by a process of forming a print pattern corresponding to the predetermined pattern on the surface of the ceramic green sheet having a thickness of 3 μm or less by the gravure printing method. Thus, a multilayer ceramic electronic component in which the ceramic green sheet and the internal electrode are stacked is manufactured.
The opening edge is perpendicular site printing direction to the ceramic green sheet, wherein a parallel portion in the printing direction, the curvature of the parallel portion radius, smaller than the radius of curvature of the vertical portion Kusuru.
[0022]
Further, according to the present invention, a predetermined pattern is formed by assembling a plurality of recesses each surrounded by an opening edge formed of a curved surface having a radius of curvature R in a range of 2 μm ≦ R <15 μm and filled with a transfer product. A gravure printing plate used for manufacturing a multilayer ceramic electronic component is formed, which is configured to form a printing pattern corresponding to the predetermined pattern on the surface of a ceramic green sheet having a thickness of 3 μm or less.
The opening edge is perpendicular site printing direction to the ceramic green sheet, wherein a parallel portion in the printing direction, the curvature of the parallel portion radius, smaller than the radius of curvature of the vertical portion Kusuru.
[0023]
DETAILED DESCRIPTION OF THE INVENTION
A configuration of the gravure printing plate according to the first embodiment and a method for forming an internal electrode pattern using the same will be described with reference to FIGS. 1, 2, 5, and 6.
FIG. 1A is a partially enlarged plan view of a gravure printing plate, and FIGS. 1B and 1C are partially enlarged sectional views.
FIG. 2 is an enlarged view of the printing unit.
As shown in FIG. 1, the gravure printing plate 53 is formed with an aggregate of print patterns formed by the recessed portions 1 arranged and separated by a grid-like bank portion 2. The opening edge of the recess 1 is processed so that the predetermined radius of curvature R is 2 μm ≦ R <15 μm, thereby forming the curved surface portion 4. The curved surface portion 4 is processed by etching using a chemical reaction.
[0024]
The overall structure of the gravure printing plate is the same as that of the gravure printing plate shown in FIG. The gravure printing process is the same as the process shown in FIG.
[0025]
By using the gravure printing plate 53 provided with such a curved surface portion 4, when the conductive paste 31 is printed, the curved surface portion 4 at the opening edge of the concave portion 1 of the gravure printing plate 53 (the curved surface portion 4 on the top surface of the bank portion 2). Can reduce the pressure applied when contacting the ceramic green sheet 32. Therefore, damage to the ceramic green sheet 32 can be suppressed, and defects generated based on the damage can be suppressed.
[0026]
Next, the predetermined curvature radius R of the curved surface portion of the concave portion formed on the gravure printing plate is changed between 0.2 μm to 20 μm, and a conductive paste containing Ni is gravure printed on a ceramic green sheet having a thickness of 3 μm, Table 1 shows the results of examining the degree of occurrence of the damaged portion and the coating thickness. The number of damaged portions is the number of holes having a diameter of 1 .mu.m or more existing in the range of 100 cm @ 2 in the ceramic green sheet. The coating thickness of the conductive paste is shown assuming that the coating thickness of the conductive paste when the curved surface portion is not formed is 100%. In addition, about the curved surface part of a recessed part, after forming a recessed part, it formed by performing a chemical process further, and the predetermined curvature radius R of the curved surface part was changed with the time of the chemical process.
[0027]
[Table 1]

[0028]
As shown in Table 1, when the thickness was less than 2 μm, a hole having a diameter of 1 μm or more was present in the ceramic green sheet. Therefore, from this result, in order to prevent a damaged portion from occurring in the ceramic green sheet, a curved surface portion is provided at the opening edge of the concave portion 1 in the gravure printing plate, and the predetermined radius of curvature R of the curved surface portion is set to 2 μm or more. I know it ’s good.
[0029]
Further, the larger the predetermined radius of curvature R of the curved surface portion, the thinner the applied thickness of the conductive paste. This is because the width of the top surface of the bank portion is constant, and as the predetermined radius of curvature R of the curved surface portion increases, the width of the bank portion becomes thicker and the concave portion becomes smaller, so the filling volume of the conductive paste decreases. Because. From the results in Table 1, it can be seen that the predetermined radius of curvature R of the curved surface portion of the recess is preferably 10 μm or less. When the predetermined radius of curvature R of the curved surface portion of the concave portion is 15 μm or more, the degree to which the coating thickness is reduced exceeds the allowable range. On the other hand, even when the predetermined curvature radius R is increased at the bank portion having a constant width, the top surface of the bank portion becomes a curved surface portion, so that the width of the top surface of the bank portion is reduced, and the printed pattern 11 is ceramic. The green sheet enters, and as a result, the thickness of the conductive paste is reduced.
[0030]
Next, the configuration of the gravure printing plate according to the second embodiment will be described with reference to FIG.
FIG. 3 is a partially enlarged plan view of the gravure printing plate.
The gravure printing plate shown in FIG. 3 has different curvature radii R of the curved surface portions 4a to 4d formed at the opening edges of the recesses, and the other configurations are the same as those of the gravure printing plate shown in FIG. is there.
[0031]
For example, in the example shown in FIG. 3, the bank portion 2 of the gravure printing plate is parallel and perpendicular to the printing direction, and the curved surface portions 4a and 4c formed perpendicular to the printing direction have a large predetermined radius of curvature R. The curved surface portions 4b and 4d formed in parallel with the printing direction can have a predetermined radius of curvature R smaller than the curved surface portions 4a and 4c. This is because the curved surface portions 4b and 4d formed parallel to the printing direction are always in contact with the ceramic green sheet when the conductive paste in the recess 1 is transferred. On the other hand, the curved portions 4a and 4c formed perpendicular to the printing direction are pressed only at the beginning and the end when the concave portion 1 transfers the conductive paste, so that the amount of pressing on the ceramic green sheet at a time increases. Therefore, the curved surface portions 4b and 4d in the region substantially parallel to the printing direction are less affected by the pressure applied to the ceramic green sheet than the curved surface portions 4a and 4c in the region substantially perpendicular to the printing direction, and the predetermined curvature radius R Can be reduced.
[0032]
In the above-described embodiment, the case where the concave portions are arranged in parallel and perpendicular to the printing direction is shown, but the same effect can be obtained by adjusting the predetermined radius of curvature corresponding to the printing direction.
[0033]
Further, in the above-described embodiment, the curved surface portion 4 is formed by etching using a chemical reaction after the concave portion is formed. However, the present invention is not limited to this. For example, an etching time is required when forming the concave portion. By controlling the above, a concave portion having a curved surface portion can be obtained.
[0034]
Furthermore, in the above-described embodiment, the case where the internal electrode pattern is formed by gravure printing has been described. However, the present invention is not limited to this. For example, a step absorbing dielectric is provided in a portion other than the internal electrode on the ceramic green sheet. The present invention can also be applied to gravure printing of a pattern. In short, the present invention can be applied to all methods of gravure printing a predetermined pattern on a ceramic green sheet.
[0035]
【The invention's effect】
According to the present invention, the opening edges of a large number of concave portions are curved surfaces having a predetermined radius of curvature R, and the predetermined radius of curvature R is 2 μm ≦ R <15 μm. A transfer product such as a paste or a dielectric paste can be transferred, and when a multilayer ceramic electronic component is manufactured, problems such as sheet attack caused by a damaged portion can be reduced.
[0036]
In addition, when a conductive paste is used as a transfer and an internal electrode pattern is printed, it is possible to prevent a short circuit failure or an insulation resistance failure due to a damaged portion. In addition, since the applied thickness of the transfer product is not so thin, problems such as internal electrode breakage do not occur.
[0037]
[Brief description of the drawings]
FIG. 1 is a partially enlarged plan view and a partially enlarged side view of a gravure printing plate according to a first embodiment. FIG. 2 is an enlarged view of a printing unit in a gravure printing process according to the first embodiment. Fig. 4 is a partially enlarged plan view of a gravure printing plate according to an embodiment of the present invention. Fig. 4 is a side sectional view of a multilayer ceramic capacitor. Fig. 5 is a plan view, partially enlarged plan view, and partially enlarged side view of a conventional gravure printing plate. ] Schematic diagram of internal electrode pattern printing (gravure printing) process [Fig. 7] Enlarged view of printing section of conventional gravure printing process [Explanation of symbols]
53-gravure printing plate 1-concave portion provided in gravure printing plate 10-bank portion separating the concave portion 1 provided in gravure printing plate 10-ridge portions 4, 4a to 4d- constituting the opening edge of the concave portion 1 Occurs in the curved surface portion 20 provided at the opening edge of the recess 1 -laminated ceramic capacitor 21 -dielectric layer 22 -internal electrode 23 -element body 24 -external electrode 31 -conductive paste 32 -ceramic green sheet 33 -ceramic green sheet 32 Damaged part 51-carrier film 52-tension roll 54-impression cylinder 55-conductive paste tank 56-doctor blade 57-drying furnace

Claims (2)

For a gravure printing plate in which a concave portion surrounded by an opening edge composed of a curved surface having a radius of curvature R in the range of 2 μm ≦ R <15 μm is formed on a roll surface, a transfer product serving as an independent internal electrode Filling the recess;
Transferring the transferred material filled in the recess to the surface of a ceramic green sheet having a thickness of 3 μm or less,
The transcript by stacking a plurality of the ceramic green sheet that is transferred by the process, the a ceramic green sheet and method for manufacturing a laminated ceramic electronic component wherein the internal electrode producing a multilayer ceramic electronic component are stacked ,
The opening edge includes a portion perpendicular to the printing direction to the ceramic green sheet and a portion parallel to the printing direction,
A method of manufacturing a multilayer ceramic electronic component, wherein a curvature radius of the parallel part is smaller than a curvature radius of the perpendicular part. A concave portion surrounded by an opening edge composed of a curved surface having a radius of curvature R in the range of 2 μm ≦ R <15 μm is formed on the roll surface,
A multilayer ceramic electronic component, wherein a transfer product serving as an independent internal electrode is filled in the recess, and the transfer product filled in the recess is transferred to the surface of a ceramic green sheet having a thickness of 3 μm or less. A gravure printing plate for use in the manufacturing process ,
The opening edge includes a portion perpendicular to the printing direction to the ceramic green sheet and a portion parallel to the printing direction,
A gravure printing plate, wherein a curvature radius of the parallel part is smaller than a curvature radius of the perpendicular part.

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