JP2015226036A - Print electrode pattern for multilayer ceramics capacitor and method of manufacturing multilayer ceramics capacitor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a print electrode pattern for multilayer ceramics capacitor which does not cause any cut or tear on a green sheet used for manufacture, when peeling the green sheet from a base film, and to provide a method of manufacturing a multilayer ceramics capacitor.SOLUTION: In a print electrode pattern for multilayer ceramics capacitor where a rectangular internal electrode 13 is printed on a continuous body of green sheet reinforced by a base film, the continuous body of green sheet has a strip dummy pattern 14 continuous in a direction perpendicular to the peeling direction, at a position being peeled from the base film, and one side end of the dummy pattern 14 is printed continuously with at least a part of the tip of adjoining internal electrodes.

Description

  The present invention relates to a printed electrode pattern for a multilayer ceramic capacitor and a method for manufacturing the multilayer ceramic capacitor. More specifically, when manufacturing a multilayer ceramic capacitor (hereinafter also referred to as “MLCC”), a dielectric is formed from a base film. The present invention relates to a printed electrode pattern for internal electrodes that is less likely to be cut or torn when a green sheet is peeled off, and a method for manufacturing a multilayer ceramic capacitor.

  As electronic devices such as cellular phones and digital devices become lighter, thinner, and smaller, multilayer ceramic capacitors that are chip parts are also required to be smaller, higher capacity, and higher performance. The most effective means for realizing these is to reduce the thickness of the internal electrode layer and the dielectric layer to increase the number of layers.

This MLCC is generally manufactured as follows (see, for example, Patent Document 3). First, a dielectric green sheet containing barium titanate (BaTiO ₃ ) as a main component and an organic binder such as polyvinyl butyral is formed on a base film using a roll coater method or the like. Then, a conductive paste as a main electrode in which conductive powder is a main component on a green sheet reinforced with a base film and dispersed in a vehicle containing a resin binder and a solvent is printed in a predetermined pattern by means such as printing. After coating and forming, the solvent is removed by drying to form an internal electrode layer.

  Subsequently, the ceramic green sheet having a plurality of internal electrode layers formed on the base film is cut and peeled from the base film at a predetermined length, and then punched out at a predetermined size. Next, a green laminate in which a predetermined number of punched green sheets are stacked in a multi-layered state and bonded together is obtained. Next, the raw laminate is cut with a cutter or the like, debindered in an oxidizing atmosphere or an inert atmosphere, and then heated and fired in a reducing atmosphere so that the internal electrodes are not oxidized. Get the prime body. Finally, an external electrode paste is applied to both end faces of the MLCC element body, and after firing, nickel plating or the like is applied to the external electrode to obtain MLCC.

Such a MLCC manufacturing method is also described in, for example, Patent Document 1, which describes a method in which a green sheet is continuously peeled from PET as a base film, and the printed sheet is cut while adsorbed on an adsorption plate. Yes.
Moreover, although the grain sheet has become thinner with the miniaturization of the MLCC, a problem that the film is cut or torn easily in handling is likely to occur. Therefore, for example, Patent Document 2 proposes a method in which a dummy layer is formed around the internal electrode to improve the handleability when the green sheet has a thickness of 10 μm or less.

However, in recent years, the miniaturization of MLCC is further accelerated, the thickness of the green sheet is often 2 μm or less, and the thickness of the printed electrode pattern is also reduced. As a result, when even a part of the end portion of the green sheet is cut, the progress may not be suppressed even in the dummy layer formed around the periphery as described in Patent Document 2.
Therefore, even when an ultra-thin green sheet having a thickness of 2 μm or less is used, there is a demand for a method of peeling the green sheet formed with the internal electrode layer from the base film without being cut or torn.

Japanese Patent Laid-Open No. 05-090068 JP 08-222474 A Japanese Patent Laid-Open No. 06-140282

  The object of the present invention is to reduce the thickness of the MLCC and to reduce the thickness of the green sheet on which the internal electrode serving as the element body is printed, and to use an ultra-thin green sheet of 2 μm or less. Provides a printed electrode pattern for internal electrodes and a method for producing a multilayer ceramic capacitor that does not cause the problem that the very weak green sheet is cut or torn when the green sheet is peeled off from the base film There is to do.

  The present inventor has conducted extensive studies to solve the above-mentioned problems, and as a result of examining in detail the occurrence of breaks and tears that occur when the green sheet is peeled off from the base film, many of these occurrences occur at the end of the green sheet. If the electrode pattern is arranged in a grid, the breaking strength of the green sheet can be reduced between the columns where the electrode pattern is printed and the columns where it is not printed. It has been found that there may be a difference and may become the starting point of tearing, and has a strip-like dummy pattern continuous in a direction perpendicular to the peeling direction at a position peeled from the base film, In order to complete the present invention, it is confirmed that these problems can be solved by continuously printing one end of the dummy pattern and at least a part of the tip of the adjacent internal electrode. Was Tsu.

  That is, according to the first aspect of the present invention, in the printed electrode pattern for a multilayer ceramic capacitor in which a rectangular internal electrode is printed on a continuous body of green sheets reinforced with a base film, the continuous body of green sheets Has a strip-like dummy pattern continuous in a direction perpendicular to the peeling direction at a position peeled from the base film, and one end of the dummy pattern is at least a part of the adjacent internal electrode A printed electrode pattern for a multilayer ceramic capacitor is provided which is continuously printed with a tip portion.

According to a second aspect of the present invention, there is provided a printed electrode pattern for a multilayer ceramic capacitor according to the first aspect, wherein the internal electrodes are arranged in a staggered manner.
According to a third aspect of the present invention, in the first aspect, the dummy pattern is continuously printed with an internal electrode located outside, the printed electrode for a multilayer ceramic capacitor, A pattern is provided.
According to a fourth aspect of the present invention, there is provided the multilayer ceramic capacitor printing according to the third aspect of the present invention, wherein the dummy pattern is also continuously printed with an inner electrode located inside. An electrode pattern is provided.
According to a fifth aspect of the present invention, there is provided the printed electrode pattern for a multilayer ceramic capacitor according to the first aspect, wherein the thickness of the dummy pattern is substantially equal to the thickness of the internal electrode. The
According to a sixth aspect of the present invention, there is provided the printed electrode pattern for a multilayer ceramic capacitor according to the first aspect, wherein the dummy pattern has a width of 0.5 mm or more.
According to a seventh aspect of the present invention, there is provided the printed electrode pattern for a multilayer ceramic capacitor according to the first aspect, wherein the green sheet has a thickness of 2 μm or less.

According to an eighth aspect of the present invention, there is provided a method for producing a multilayer ceramic capacitor using the printed electrode pattern for a multilayer ceramic capacitor according to any one of the first to seventh aspects,
A printing step (A) for printing a rectangular internal electrode and a dummy pattern on a continuous body of green sheets reinforced with a base film, and the printed green sheet continuous body is fed out and cut while peeling from the base film. And a peeling / cutting step (B) to be performed, wherein the continuous green sheet peeled in the step (B) is cut into the strip-shaped dummy pattern into a green sheet piece of a predetermined size. A method for manufacturing a multilayer ceramic capacitor is provided.
According to a ninth aspect of the present invention, in the eighth aspect, the internal electrode and the dummy pattern are both formed of a conductive paste containing nickel powder. Is provided.

According to the present invention, since there is a dummy pattern printed and formed in a direction orthogonal to the peeling direction at the end of the green sheet on which the internal electrode is formed, which is the starting point of peeling from the base film, the peeling It is possible to increase the strength of the end portion of the green sheet at which the start is started.
Moreover, since this dummy pattern is partially continuously printed with the internal electrode, the stress when peeling from the base film can be effectively dispersed.
Furthermore, when the green sheet continuous body is cut into a predetermined size, the strength of the green sheet end portion is improved by cutting the portion where the dummy pattern formed on the end portion of the internal electrode is cut in the longitudinal direction. It can be used effectively and is more effective.

It is an apparatus schematic diagram which shows an example of a MLCC element | base_body production process. It is a schematic sectional drawing which expands and shows the green sheet cutting part in FIG. It is the schematic which shows the conventional printing pattern. It is the schematic which shows an example of the printing pattern of this invention. It is the schematic which shows the other printing pattern of this invention.

  Hereinafter, the printed electrode pattern for MLCC and the method for producing MLCC of the present invention will be described in detail with reference to the drawings.

1. Printed electrode pattern for multilayer ceramic capacitor The printed electrode pattern for multilayer ceramic capacitor of the present invention is a printed electrode pattern for multilayer ceramic capacitor in which a rectangular internal electrode is printed on a continuous body of green sheets reinforced with a base film. The continuous body of the green sheets has a strip-like dummy pattern continuous in a direction orthogonal to the peeling direction at a position where the green sheet is peeled from the base film, and one end portion of the dummy pattern is adjacent to the inside. It is characterized by being continuously printed with at least a part of the tip of the electrode.
The printed electrode pattern for a multilayer ceramic capacitor of the present invention comprises an internal electrode and a dummy pattern that are printed on a green sheet continuum.

(1) Green sheet The green sheet used in the present invention is a sheet-like continuum formed on a base film such as PET with a binder prepared by mixing a dielectric composition such as a conductive ceramic powder and an organic resin. It functions as a dielectric in the capacitor. As the dielectric composition, barium titanate (BaTiO ₃ ) or the like is the main component, and as the organic resin, polyvinyl butyral, methylcellulose, or the like is used.

  In the present invention, a thin green sheet having a thickness of 2 μm or less, preferably 1 μm or less is used. As a result, the internal electrode layer disposed on the green sheet can be thinned and the capacitor capacity can be increased.

(2) Internal electrode The material of the internal electrode used in the present invention is not particularly limited. For example, in addition to refractory precious metals such as Pd, Pt, and Ag / Pd, base metal materials such as Ni and Cu can also be used. . In particular, Ni is useful as a metal material for internal electrodes, and this Ni powder is preferably used as a conductive paste by kneading with an organic vehicle and an organic solvent. The average particle diameter of the Ni powder is 2 μm or less, and the finer is the better the printability, but when it is 0.05 μm or less, the dispersibility deteriorates, so 0.1 to 1 μm is more preferable.

  In the present invention, it is not limited by the shape and arrangement of the internal electrodes formed on the green sheet, but is usually arranged in a large number of vertically long rectangular shapes. Can be arranged. Arranging the internal electrodes in a staggered manner is preferable in that the stress at the time of peeling from the base film can be more effectively dispersed.

(3) Dummy pattern In the present invention, a dummy pattern printed and formed in a direction orthogonal to the peeling direction is formed at the end of the green sheet on which the internal electrode is formed, which is the starting point of peeling from the base film. Has been.

The reason why the dummy pattern is formed is to increase the strength of the edge of the green sheet that is the peeling start point. In particular, since the initial stress at the start of peeling is higher than that during continuous peeling, if there is a weak part in the green sheet edge area at the start of peeling, the crack is likely to occur in that part, and the width of the dummy pattern Is not sufficiently wide, the effect of improving the strength is not sufficiently obtained, and the dummy pattern may be broken.
In the present invention, since the dummy pattern and a part of the internal electrode are continuously printed to reduce the number of weak portions in the green sheet end region where the initial stress is applied, the occurrence of cracks can be suppressed. When continuous peeling is started, the stress necessary for peeling becomes lower than that at the start, so that the generation of cracks is suppressed.

  In the present invention, the material for the dummy pattern is not particularly limited and can be the same material as the internal electrode, but in particular, from the viewpoint of workability, material cost, etc., a conductive paste containing Ni powder is used. Preferably

  In the printed electrode pattern for a multilayer ceramic capacitor of the present invention, it is preferable that the thickness of the dummy pattern is substantially equal to the thickness of the internal electrode. If the thickness is not the same as the thickness of the internal electrode, the effect of the dummy pattern cannot be obtained sufficiently, or conversely, the strength becomes too strong and the stress concentrates and may be broken rearward.

  The width of the dummy pattern is preferably 0.5 mm or more. Thereby, generation | occurrence | production of the crack and fracture | rupture which arise at the time of green sheet peeling can be prevented. The width is more preferably 0.8 mm or more, and particularly preferably 1.0 mm or more. However, if the thickness exceeds 5.0 mm, cracks and breakage of the green sheet can be effectively prevented, but the portion to be discarded becomes large, which is not preferable in terms of cost.

(4) Printed electrode pattern In the printed electrode pattern for multilayer ceramic capacitors, a general arrangement can be applied to the internal electrode portion printed on the green sheet.

  In the present invention, a strip-like dummy pattern continuous in a direction orthogonal to the peeling direction is disposed on the green sheet, and one end of the dummy pattern is at least a tip of an adjacent internal electrode And an electrode pattern is printed on the green sheet.

  In the present invention, the internal electrodes can be arranged in a lattice or zigzag pattern, but when the internal electrodes are arranged in a zigzag pattern, the stress at the time of peeling from the base film can be more effectively dispersed. preferable. Further, by arranging the internal electrodes in a staggered manner, the occurrence of locations where the strength becomes weaker with respect to the line where peeling occurs is reduced, and therefore the frequency of occurrence of cracks during green sheet peeling can be further reduced.

  FIG. 4 shows an electrode pattern when the internal electrodes 13 are arranged in four rows in a staggered manner. The two leading ends of the internal electrode located on the right end, that is, on the outside, and the internal electrodes located on the second column from the left, that is, in the middle, are printed continuously with the dummy pattern 14. By arranging the internal electrodes in this manner, as described above, the stress when peeling from the base film can be effectively dispersed. Of the internal electrodes, only the internal electrode located on the outside or only one tip of the internal electrode located in the middle may be printed continuously with the dummy pattern, but the stress when peeling from the base film Dispersion is slightly reduced. Note that the internal electrode printed continuously with the dummy pattern is discarded and does not function as a capacitor.

  Further, even when the internal electrodes are arranged in 3 or 5 rows, at least a part of the front end portion of the adjacent internal electrodes is printed continuously with the dummy pattern, as in the case where the internal electrodes are arranged in 4 rows. In addition, the electrode pattern of the present invention can be formed. FIG. 5 shows a mode in which two internal electrodes 13 in the rightmost column and the central column are connected to the dummy pattern 14 in a grid pattern of five columns and four stages with respect to the conventional print pattern of FIG. As described above, when the internal electrodes are arranged in a lattice pattern, as in the case of the staggered arrangement, it is possible to reduce the occurrence of the portion 16 where the strength is weak with respect to the line where the peeling occurs. Is the same as the staggered arrangement, and the area that is discarded and does not function as a capacitor increases. Therefore, the material cost is higher than in the staggered arrangement.

  3 to 5 show a printed electrode pattern composed of a small number of internal electrodes for the sake of convenience of explanation, in the present invention, the arrangement of internal electrodes can effectively disperse the stress at the time of peeling. However, the present invention is not limited to the above. In recent years, internal electrodes are arranged in a larger number of rows and stages, and the total number is often several tens to several hundreds. The present invention is preferably applied even to a printed electrode pattern composed of such a large number of internal electrodes.

2. Manufacturing method of multilayer ceramic capacitor The manufacturing method of the multilayer ceramic capacitor of the present invention is a manufacturing method of a multilayer ceramic capacitor using the printed electrode pattern for the multilayer ceramic capacitor, and a continuous body of green sheets reinforced with a base film A printing process (A) for printing a rectangular internal electrode and a dummy pattern on the upper side, and a peeling / cutting process (B) for feeding the printed green sheet continuous body and cutting it while peeling from the base film. The green sheet continuum peeled in the step (B) is cut into the strip-shaped dummy pattern to form green sheet pieces of a predetermined size.

(1) Printing process (A)
First, a continuous body of green sheets reinforced with a base film is prepared, and the internal electrode and a dummy pattern (print pattern) are formed thereon by screen printing or the like. As described above, it is preferable that both the internal electrode and the dummy pattern are formed of a conductive paste containing nickel powder. The thickness and width, the arrangement of the internal electrodes, and the shapes of the internal electrodes and the dummy pattern (print pattern) are also as described above.

(2) Peeling / cutting process (B)
The green sheet 1 on which the internal electrode reinforced with the base film is formed is continuously supplied from the supply roll 4 as shown in FIG. 1 and peeled from the base film 3 by the cutting unit 6. The internal electrode printed green sheet 2 having a predetermined length is cut.

  Here, the process of peeling the internal electrode printed green sheet 2 from the base film 3 will be described in more detail with reference to FIG. The base film 3 is peeled from the internal electrode printed green sheet 2 by being bent at an acute angle along the peeling plate 10. At that time, the internal electrode printing green sheet 2 is held by the suction plate 9. The peeled internal electrode printed green sheet 2 is cut immediately after peeling by the cutter unit 12, and the cut portion (15 in FIGS. 3 and 4) is in the dummy pattern 14.

  Conventionally, as shown in FIG. 3, since there was no dummy pattern, the green sheet is easily cracked and torn with an initial crack that occurs at the end of the cut portion 15 with a weaker strength than the initial crack. It was growing up. That is, when the green sheet continuous body on which the MLCC printed electrode pattern is printed is cut into a predetermined size after being peeled off from the base film, the green sheet may be broken or broken to disturb the arrangement of the internal electrodes 13, The surface is roughened, making uniform lamination difficult, and the sheet itself cannot be used.

When the width of the dummy pattern 14 is 0.5 mm or more and 5.0 mm or less, it is preferable for the work of peeling / cutting.
If it is less than 0.5 mm, it may not be possible to cut from end to end within the dummy pattern due to variations in position accuracy at the time of cutting, and if a portion without a dummy pattern occurs, a crack will occur from that portion to the end of the green sheet, Since it may lead to cutting or breaking, it is not preferable. If the width of the dummy pattern is 0.5 mm or more, there is no problem from the point of cutting or tearing. However, since the dummy pattern is a part that is not used in the product, it is 5 for efficient use of the green sheet and internal electrode material. 0.0 mm or less is preferable. A more preferable width is 1 to 3 mm.

(3) Step after cutting (C)
Thereafter, the cut green sheet is transferred to the punching unit 7, punched as an internal electrode printing green sheet 2 to a predetermined size, and a predetermined number of sheets are stacked in the stacking unit 8.

  In the present invention, in order to further improve the strength of the green sheet end, when the green sheet continuous body is cut into a predetermined size, a dummy pattern is formed at the end of the internal electrode. In No. 7, it is cut so that the periphery becomes one size smaller.

  Next, a green laminate in which a predetermined number of punched green sheets are stacked in a multi-layered state and bonded together is obtained. This raw laminate is cut with a cutter or the like, debindered in an oxidizing atmosphere or inert atmosphere, and then heated and fired in a reducing atmosphere so that the internal electrodes are not oxidized. An MLCC body is obtained. Next, an external electrode paste is applied to both end faces of this MLCC body, and after firing, nickel plating or the like is applied to the external electrodes to form MLCC.

  EXAMPLES Hereinafter, although this invention is demonstrated in detail and concretely based on an Example, this invention is not limited at all by the Example.

Example 1
A 2 μm thin green sheet was formed on a PET film serving as a base film by a roll coater method. Next, a metal powder made of Ni (manufactured by JFE Mineral Co., Ltd., average particle size 0.2 μm) and an organic resin (ethyl cellulose) so as to form a staggered electrode pattern having dummy patterns at the ends as shown in FIG. ) And a solvent (terpineol) were printed, and then dried in the atmosphere at about 60 to 80 ° C. to remove the solvent, thereby forming an internal electrode layer composed of a plurality of electrodes. At that time, the width of the dummy pattern was 0.5 mm.
Thereafter, the internal electrode printing green sheet continuum reinforced with the obtained base film is peeled off from the base film using a sheet punching and peeling device as shown in FIG. An internal electrode printing green sheet was obtained.
This operation was repeated to produce 100 internal electrode printing green sheets for lamination, and the number of cuts and tears was confirmed, and the sheet defect rate generated at the time of peeling was confirmed. The results are shown in Table 1.

(Example 2)
A laminated internal electrode printed green sheet was prepared in the same manner as in Example 1 except that the thickness of the green sheet was 1 μm, and the defect rate was confirmed. The results are shown in Table 1.

(Example 3)
A laminated internal electrode printed green sheet was prepared in the same manner as in Example 1 except that the electrode pattern to be printed was arranged in a lattice, and the defect rate was confirmed. The results are shown in Table 1.

(Comparative Example 1)
A lamination internal electrode printing green sheet was prepared by the same method as in Example 1 except that a dummy pattern was not formed on the electrode pattern to be printed, and the defect rate was confirmed. The results are shown in Table 1.

(Comparative Example 2)
A lamination internal electrode printing green sheet was prepared in the same manner as in Example 1 except that the electrode pattern to be printed was not arranged in a lattice pattern but a dummy pattern was formed, and the defect rate was confirmed. The results are shown in Table 1.

"Evaluation"
From Table 1 showing the above results, when no dummy pattern is formed as in Comparative Examples 1 and 2, the defect rate due to cutting or tearing is 10% or more, which is preferable in terms of productivity and cost. I understand that there is no. On the other hand, in Examples 1 to 3, since the dummy pattern is continuously formed at the end of the electrode pattern according to the present invention, the defect rate is greatly improved to 2% or less. In particular, in Example 1, since defects due to cutting or tearing did not occur, staggered arrangement is a preferred pattern of the present invention.

  The multilayer ceramic capacitor of the present invention is incorporated as a chip component in an electronic device such as a mobile phone or a digital device, and employs a green sheet having a specific printed electrode pattern to make the internal electrode layer and the dielectric layer thinner. Thus, the number of layers can be increased, and further downsizing, higher capacity, and higher performance can be realized.

DESCRIPTION OF SYMBOLS 1 Internal electrode printing green sheet with base film 2 Internal electrode printing green sheet 3 Base film 4 Supply roll 5 Winding roll 6 Cutting unit 7 Punching unit 8 Laminating unit 9 Suction plate 10 Release plate 11 Cutting stage 12 Cutter unit 13 Internal electrode 14 Dummy pattern 15 Cutting line 16 Reduced strength line

Claims (9)

In a printed electrode pattern for a multilayer ceramic capacitor in which rectangular internal electrodes are printed on a continuous body of green sheets reinforced with a base film,
The continuous body of the green sheets has a strip-like dummy pattern continuous in a direction orthogonal to the peeling direction at a position where the green sheet is peeled from the base film, and one end portion of the dummy pattern is adjacent to the inside. A printed electrode pattern for a multilayer ceramic capacitor, wherein the printed electrode pattern is continuously printed on at least a part of the tip of the electrode.   The printed electrode pattern for a multilayer ceramic capacitor according to claim 1, wherein the internal electrodes are arranged in a staggered pattern.   2. The printed electrode pattern for a multilayer ceramic capacitor according to claim 1, wherein the dummy pattern is continuously printed with an internal electrode located outside. 3.   4. The printed electrode pattern for a multilayer ceramic capacitor according to claim 3, wherein the dummy pattern is further continuously printed with an internal electrode located on the inner side.   2. The printed electrode pattern for a multilayer ceramic capacitor according to claim 1, wherein the thickness of the dummy pattern is substantially equal to the thickness of the internal electrode.   The printed electrode pattern for a multilayer ceramic capacitor according to claim 1, wherein a width of the dummy pattern is 0.5 mm or more.   The printed electrode pattern for a multilayer ceramic capacitor according to claim 1, wherein the green sheet has a thickness of 2 μm or less. A method for manufacturing a multilayer ceramic capacitor using the printed electrode pattern for a multilayer ceramic capacitor according to any one of claims 1 to 7,
A printing step (A) for printing a rectangular internal electrode and a dummy pattern on a continuous body of green sheets reinforced with a base film, and the printed green sheet continuous body is fed out and cut while peeling from the base film. And a peeling / cutting step (B)
The method for producing a multilayer ceramic capacitor, wherein the green sheet continuous body peeled in the step (B) is cut into the green sheet pieces of a predetermined size by being cut in the band-shaped dummy pattern.   The method for manufacturing a multilayer ceramic capacitor according to claim 8, wherein both the internal electrode and the dummy pattern are formed of a conductive paste containing nickel powder.

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