JPH0645185A - Multilayer ceramic capacitor and manufacture thereof - Google Patents

Abstract

(57) [Summary] [PROBLEMS] To provide a low-cost, high-quality, inexpensive monolithic ceramic capacitor that can be made into a flat surface by printing once and a manufacturing method thereof. [Structure] A 14-layer dummy layer 5 is formed by plating a stainless steel surface plate 4 with a stainless mesh having two kinds of aperture ratios A9 and B10, and then the internal electrode paste is formed using the stainless mesh. Printing and ceramic powder paste printing are alternately laminated to form a dielectric layer having 76 internal electrode print layers 6 and 75 ceramic powder print layer 7 internal electrode layers. A ceramic sintered body 1 of a laminated body in which 14 dummy layers 5 are formed by using a mesh is obtained, and silver paste is applied to the exposed end surface portion of the internal electrode layer 2 of the ceramic sintered body, and the terminal electrode 3 And a method for manufacturing the same.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a laminated ceramic capacitor used in various electronic devices and a method for manufacturing the same.

[0002]

2. Description of the Related Art A conventional monolithic ceramic capacitor is formed by forming a ceramic green sheet (hereinafter simply referred to as a sheet) on a ceramic slurry obtained by mixing a ceramic powder with an organic binder by a doctor blade method or a roll method. The internal electrode paste is printed on, and a plurality of sheets on which the internal electrode print layer is formed are stacked to form a dielectric layer having an internal electrode layer, and the internal electrode paste is printed above and below the dielectric layer. Method of stacking multiple non-sheets and pressing a dummy layer with only green sheets, or after repeating the ceramic powder paste printing consisting of ceramic powder and organic binder to form a dummy layer, internal electrode paste printing and ceramic powder paste printing Alternatingly to form a dielectric layer, and then a dummy layer To obtain a laminate by a method of repeatedly printing a ceramic powder paste, which binder removal, sintering, it was prepared by adding processing such as forming the terminal electrodes.

The former method of stacking sheets has a high stacking speed and can be produced with high efficiency, but the sheet thickness is 2
When the thickness is 0 μm or less, static electricity of the sheet and the carrier film causes film cracking due to peeling of the sheet, and handling property is extremely deteriorated, so that lamination becomes difficult. On the other hand, in the latter method using screen printing, the printing thickness can be easily set to 10 μm or less, so that the dielectric layer for alternately laminating the internal electrode paste printing and the ceramic powder paste printing can be made thin, and the effective dielectric layer Capacitance per body stack can be increased. However, since the printing is repeated by alternately laminating the internal electrode paste printing and the ceramic powder paste printing, a step of 20 to 50 μm occurs in the thickness portion of the internal electrode paste printing due to the print layer made of ceramic powder, and the internal electrode pattern Ceramic cracks occur along the
There is a drawback that undulations of the internal electrodes occur and repeated printing of several tens of times is required to eliminate the step, and the stacking speed is extremely slow and the production cost is high.

[0004]

As described above, the present invention solves the problem that a step is generated due to the thickness of the internal electrode paste printing, and has high productivity and low cost, and a method of manufacturing the same. Is provided.

[0005]

In order to solve this problem, the present invention has a structure in which a printed layer of internal electrodes composed of a metal component and a printed layer composed of ceramic powder of a ferroelectric layer are alternately formed. In the method for manufacturing a monolithic ceramic capacitor, an internal electrode paste is printed on a top surface of a printing layer made of a predetermined ceramic powder by a printing screen having two or more different aperture ratios, and then the ceramic powder and an organic binder are used by using the printing screen. A method of manufacturing a laminated ceramic capacitor, comprising the steps of printing a ceramic powder paste consisting of :, alternately laminating the internal electrode paste printing and the ceramic powder paste printing, and screen-printing to produce a laminated body. And is manufactured by the manufacturing method of. It is to provide a ceramic capacitor.

[0006]

According to the manufacturing method of the present invention, as shown in FIG. 2, the stainless steel mesh 8 having an aperture ratio A9 of 43% is used.
Forming a print pattern on the screen emulsion 12 by
A plating layer 11 having a thickness of 10 μm is applied to the stainless steel mesh, and then unnecessary emulsion is dissolved with a solvent to leave a screen emulsion 12, leaving an aperture ratio A9 and 10 of 43%.
A stainless mesh printing screen with an aperture ratio B10 of 10% is produced. These two types of aperture ratio A9 and aperture ratio B
When a laminated body of a multilayer ceramic capacitor is formed with a printing screen having 10, the paste supplied from the aperture ratio A9 of 43% is large and the paste supplied from the aperture ratio B10 of 10% is small. The end portion of the printing surface printed by this printing screen is thin because the amount of paste supplied is small, and the portion having an aperture ratio A9 of 43% is large due to the large amount of paste supplied. By using the printing screen having these two types of aperture ratio, the step of 20 to 50 μm in the thickness portion of the internal electrode paste printing by the printing layer made of ceramic powder is eliminated. In this case, there may be two or more different aperture ratios in one screen depending on the paste used and the printing conditions. As described above, by using the printing screen having two kinds of aperture ratios for the ceramic powder paste printing and the internal electrode paste printing, the thick portion can be thinned and flattened. The difference in level can be eliminated by printing once, and it is no longer necessary to print several tens of times to eliminate the level difference, resulting in extremely high productivity.
The production cost is inevitably reduced.

[0007]

EXAMPLES The production method of the present invention will be described in detail below based on examples.

A ceramic powder paste was prepared by mixing a lead-based perovskite dielectric powder with a solvent such as ethyl cellosolve, butyl carbitol, butyl butylphthalyl glycolate, and a binder of polyvinyl butyral.
A commercially available silver-palladium paste was prepared as the internal electrode paste. As a printing screen of the internal electrode paste and the ceramic powder paste, as shown in FIG. 2, two kinds of 43% aperture ratio A9 and 10% aperture ratio B10 were formed by leaving the screen emulsion 12 and forming the plating layer 11. The applied # 400 stainless steel mesh was used. On the other hand, as the printing screen of the internal electrode paste, # 400 stainless mesh 8 having the above-mentioned two kinds of aperture ratios was used. As with the printing of the internal electrodes, the dummy layer 5 (see FIG. 1) containing only the ceramic powder paste without the printing of the internal electrode paste was plated with # 400 stainless mesh having two kinds of aperture ratios. used.

FIG. 1 (b) is a schematic diagram showing the laminated steps of the laminated ceramic capacitor and the manufacturing method thereof according to the present invention. However, (A), (B), in (b) of FIG.
(C) shows the order of stacking. As for part (A) of FIG. 1B, ceramic powder paste having two types of aperture ratios is provided on a smooth surface of a stainless steel platen #.
Printing using 400 stainless mesh, 100 ℃
To dry for 1 minute. The thickness of the print layer made of ceramic powder is about several μm, and at most about 10 μm. Further, the above work is repeated to print 14
The figure shows a process in which the dummy layer 5 having a thickness of about 100 to 140 μm is formed by repeating the process. Next, the portion (B) of FIG. 1B is the dummy layer 5 of the ceramic powder paste.
The internal electrode paste printing with a thickness of about 1 μm and the ceramic powder paste printing with a thickness of about several μm and a thickness of at least about 10 μm are alternately laminated on top of each other to give a thickness of about 10
A dielectric layer having a thickness of about 00 to 1200 μm is formed. First, the internal electrode paste is printed, dried at 100 ° C. for 1 minute, and then the ceramic powder paste is printed on the dielectric layer.
Similarly dry for 1 minute at ° C. Furthermore, the above-mentioned operation was repeated, and the internal electrode paste printing was performed 76 times and the ceramic powder paste printing was performed 75 times. A process of forming the dielectric layer having the internal electrode printed layer 6 and the internal electrode layer of the printed layer 7 made of ceramic powder in this way will be described. Note that FIG.
In the above-mentioned steps of (b) and (B) of FIG. 5, a printing screen of # 400 stainless mesh having two types of plated aperture ratios is used as a screen for printing the internal electrode paste, and the screen for printing the ceramic powder paste is used. As
By the same plating, two types of aperture ratio A of 43% and 10
A printing screen with a% B aperture was used. Since the discharge amount of the ceramic powder paste is partially controlled by the above process, the paste supplied from the opening ratio A of 43% is large and the paste supplied from the opening ratio B of 10% is small. Since the amount of paste supplied is small, the end of the printing surface printed with a printing screen having various types of aperture ratios is thin, and the part with an aperture ratio A of 43% is large in supply amount and therefore thick on the printing surface. Since both end portions are thinned by the printing screens having these two types of aperture ratios, a flat printing surface is obtained, so that a step corresponding to the printing thickness of the internal electrode is relaxed and a flat surface can be obtained. In the conventional manufacturing method, since the same # 400 stainless mesh printing screen as in the case of forming the dummy layer 5 is used as the ceramic powder paste printing, the step difference corresponding to the printing thickness of the internal electrodes cannot be alleviated and the ceramic crack occurs. did. Next, as shown in part (C) of FIG. 1B, the ceramic powder paste is printed again with a # 400 stainless mesh having the above two types of aperture ratios, and 100
After drying for 1 minute at 0 ° C., the above operation was repeated and printing was performed 14 times to form a dummy layer 5 having a thickness of about 100 to 140 μm, and a laminate having a thickness of about 1.5 mm was formed. . Then, the laminate is cut to have a width of 1 to 2 m.
m, length dimension 2 mm, thickness 1.5-1.6 mm green chip, and then debinding at 400 ° C.
Firing was performed at 1000 ° C. to obtain a ceramic sintered body. As shown in FIG. 1 (a), silver paste is applied to the exposed end surface portions of the internal electrode layers 2 of the ceramic sintered body 1, and 6
Sintered at 00 ° C. to make the terminal electrode 3, 1 V DC at 1 KHz
As a result of measuring the electrostatic capacitance, the results are shown in Table 1.

[0010]

[Table 1]

The printing screen for printing the internal electrode paste of the dielectric layer having the internal electrode layer and for printing the ceramic powder paste has two different types of apertured plates plated in the embodiment of the present invention. Although the screen was used, it is possible to use two kinds of printing screens having different aperture ratios, which are plated to form the dielectric layer having the internal electrode layer for printing the internal electrode paste and the ceramic powder paste. Good. Further, not limited to plating, it is also possible to use one in which the aperture ratio is partially changed by etching, a mold or the like. Further, the present invention is not limited to the monolithic ceramic capacitor and may be used for any multi-layer electronic component.

[0012]

As described above with reference to the multilayer ceramic capacitor of the present invention and the method of manufacturing the same based on the embodiments, two kinds of openings are provided for the internal electrode paste printing and the ceramic powder paste printing of the dielectric layer having the internal electrode layer. By using a printing screen having a ratio, conventionally, it is possible to eliminate the occurrence of cracks due to the step difference in the printing thickness of the internal electrode, the occurrence of waviness of the internal electrode, and to make a flat surface with one printing, The production cost is reduced and the quality is good.
It is also possible to provide an inexpensive monolithic ceramic capacitor and a method for manufacturing the same.

[Brief description of drawings]

FIG. 1A is a cross-sectional view of a laminated ceramic capacitor in which a terminal electrode is applied to a ceramic sintered body and sintered. FIG. 1B is a cross-sectional view showing a schematic configuration showing a laminated ceramic capacitor of the present invention and a lamination process thereof.

FIG. 2A is a plan view of a # 400 stainless steel mesh having two types of aperture ratios, in which a plating layer is formed by plating. 2 (b) is AA of FIG. 2 (a).
Sectional view.

[Explanation of symbols]

(A) Dummy layer printed part of ceramic powder (B) Dielectric layer printed part having ceramic powder and internal electrode layer (C) Dummy layer printed part of ceramic powder 1 Ceramic sintered body (dielectric layer) 2 Internal electrode layer 3 Terminal Electrode 4 Stainless Steel Surface Plate 5 Dummy Layer 6 Internal Electrode Printing Layer 7 Printing Layer Made of Ceramic Powder 8 Stainless Steel Mesh 9 Opening Ratio A 10 Opening Ratio B 11 Plating Layer 12 Screen Emulsion

Claims (2)

[Claims] 1. A method for manufacturing a monolithic ceramic capacitor having a structure in which printed layers made of ceramic powder of an internal electrode printed layer made of a metallic component and ferroelectric layers are alternately formed. After printing the internal electrode paste by a printing screen having two or more different aperture ratios on the upper surface, by printing a ceramic powder paste consisting of a ceramic powder and an organic binder using the printing screen, the internal electrode paste printing and the A method for producing a laminated ceramic capacitor, comprising the step of alternately screen-printing with ceramic powder paste to produce a laminated body. 2. A monolithic ceramic capacitor manufactured by the manufacturing method according to claim 1.