JPH05182858A - Manufacture of laminated ceramic capacitor - Google Patents

Abstract

PURPOSE:To form outer electrodes and to facilitate marking by forming slits on a laminated block, providing, after baking, marking, dividing it into element rows to form the outer electrodes, and eventually separating it into capacitor element units. CONSTITUTION:Slits 4 of V-shaped section to be divided into capacitor element units are provided on one surface of a laminated block 3 in which many capacitor structures are formed longitudinally and laterally of a green sheet 1 of dielectric ceramics and paste of inner electrodes 2. The block is baked, marks 5 are formed of paste for marking on all capacitor element zones on the surface provided with the slits 4. Then, it is so divided in one of row or column direction of the slits as to expose the electrodes 2. The obtained capacitor element rows 6 are coated with paste for outer electrodes, and baked to form the outer electrodes 7. Thereafter, it is divided into capacitor element units via the slits between the elements to be separated.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for manufacturing a monolithic ceramic capacitor having a structure in which dielectric ceramics and internal electrodes are alternately laminated.

[0002]

2. Description of the Related Art A monolithic ceramic capacitor has a rectangular parallelepiped formed by alternately laminating ceramics and internal electrodes so that the uppermost layer and the lowermost layer are ceramic layers, and the end of the internal electrode is opposite to one end face of the rectangular parallelepiped. The external electrodes are alternately exposed on the side end surfaces, and external electrodes are formed on both ends of the external electrodes. Since such a monolithic ceramic capacitor can obtain a large capacity as compared with another type of capacitor having the same volume, it is used in various electronic devices.

Conventional monolithic ceramic capacitors are usually
For example, an internal electrode paste mainly composed of Pd is applied in a pattern of a plurality of rows and a plurality of columns on the surface of a dielectric ceramic green sheet, dried, and the end portions of the internal electrodes are alternately exposed when separated into each capacitor element. In this way, a plurality of stacked green sheets are stacked on top of each other, and a plurality of reinforcing green sheets are stacked on the upper surface and the lower surface of the stacked body. The chip-shaped capacitor element is fired, and each edge of the cut end face is chamfered.
A method in which a paste for external electrodes containing as a main component is applied to both ends of the chip where the internal electrodes are exposed and fired to form external electrodes, and a mark indicating capacitance etc. is provided on the surface of each capacitor element. Is manufactured in.

However, in the conventional manufacturing method, the external electrodes are formed by cutting into small capacitor element units having a size of 3.2 mm in length and 1.6 mm in width and firing to form external electrodes. In addition, marking is also troublesome. Each of these drawbacks is a constraint on improving the productivity of the monolithic ceramic capacitor, and there is a strong demand for this improvement.

[0005]

DISCLOSURE OF THE INVENTION The present invention provides a method of manufacturing a monolithic ceramic capacitor which solves the drawbacks of the prior art, facilitates formation and marking of external electrodes, and can significantly improve productivity. The purpose is to do.

[0006]

In order to achieve the above object, the method of the present invention is one surface of a laminated block in which a large number of capacitor structures are formed vertically and horizontally by a dielectric ceramic green sheet and an internal electrode paste. A slit having a V-shaped cross section for dividing each capacitor element unit is formed, the block is fired, all the capacitor element sections on the slit surface are marked with a marking paste, and then the internal electrodes are Divide into either the row direction or the column direction of the slit so that it is exposed, and apply the external electrode paste to each obtained capacitor element column and fire it to form the external electrode. It is characterized in that it is divided into each capacitor element unit by the slit between them and separated.

FIG. 1 is a diagram conceptually explaining each step of the method of the present invention. First, as shown in (a), the internal electrodes 2 are printed on the green sheet 1 with a paste containing Pd as a main component. Next, as shown in (b), a plurality of layers of these green sheets are stacked, a green sheet on which the internal electrode paste is not printed is stacked on the uppermost layer, and the stacked block 3 is prepared by heating and press-bonding the stacked green block. Three
Slits 4 are provided on the surface of the capacitor so as to be divided into each capacitor element unit.

The laminated block with slits 3 is fired, and a glass paste for marking is screen-printed as shown in FIG. 3C, and fired to mark 5 on all the capacitor element sections on this block.

Subsequently, as shown in (d), the slits are divided in one of the row direction and the column direction of the slits so that the end portions of the internal electrodes are exposed, and the element rows in which the capacitor elements are arranged in a row. Get 6. The external electrode paste containing Ag as a main component is applied to both exposed end surfaces of the internal electrodes of the element array 6 and fired to form the external electrodes 7.

Finally, if the slits between the elements of the element array 6 are divided into individual capacitor elements and separated,
As shown in (e), it is possible to obtain a laminated ceramic capacitor 8 which is marked and has external electrodes formed thereon.

[0011]

According to the method of the present invention, the marking is performed in the state of the laminated block, and the workability is remarkably improved.
In addition, the external electrodes can be formed in each element row unit,
It is easy to handle and efficient.

[0012]

[Example] ₃₀ milky white green sheets containing BaTiO ₃ as a main component having a thickness of about 35 μm were cut into squares each having a size of about 25 mm, and 30 sheets were prepared. Print using a screen for internal electrode printing with the pattern shown, and
It is dried for 0 seconds, and alternately rotated by 180 degrees in a horizontal plane to be laminated. Ten green sheets on which the internal electrodes are not printed are laminated on the upper and lower sides of this laminated body, and a total of 30 green sheets are laminated. In a mold heated to about 80 ° C, apply a pressure of about 200 kg / cm ² to about 6
Hold for 0 seconds. By the operations up to this point, a laminated block having a size of 25 mm in length and 25 mm in width and 1100 μm in thickness is prepared.

On the surface of this laminated block, a V-shape with a sharp blade and a depth of about 1 is used to divide each capacitor element unit.
A slit of 00 μm is formed. This is fired with a temperature profile that holds it at 1300 ° C. for 2 hours. The laminated block turns brown when fired, causing sintering shrinkage, and the size is about 20 mm in length, 20 mm in width, and 65 in thickness.
It becomes 0 μm.

Next, a black glass paste for marking is screen-printed on the surface having slits.
At this time, printing is performed at once on all the divided elements.
The marking was completed by drying at 120 ° C. for 10 minutes and baking at 800 ° C. for 10 minutes.

Next, the slit is divided in one of the row and column directions of the slit so that the end of the internal electrode is exposed, and the Ag paste for the external electrode is applied to the surface where the internal electrode is exposed. , Dry at 120 ℃ for 10 minutes, then 800
The external electrodes were formed by firing at 10 ° C. for 10 minutes.

Finally, the slits between the elements were divided into individual capacitor elements to obtain 18 monolithic ceramic capacitors each having a length of 3.2 mm and a width of 2.5 mm.

[0017]

As described above in detail, according to the method for manufacturing a laminated ceramic capacitor of the present invention, the marking and the formation of the external electrode can be facilitated.

[Brief description of drawings]

FIG. 1 is a diagram conceptually explaining each step of the method for manufacturing a monolithic ceramic capacitor according to the present invention.

FIG. 2 shows internal electrode patterns used in Examples.

[Explanation of symbols]

 1 Green Sheet 2 Internal Electrode Paste 3 Multilayer Block 4 Slit 5 Mark 6 Element Row 7 External Electrode 8 Multilayer Ceramic Capacitor

Claims (1)

[Claims] 1. A rectangular parallelepiped is formed by alternately stacking ceramics and internal electrodes such that the uppermost layer and the lowermost layer are ceramic layers, and the end portions of the internal electrodes are alternately arranged on one end surface and the opposite end surface of the rectangular parallelepiped. In a method of manufacturing a laminated ceramic capacitor in which external electrodes are formed on both ends of the laminated ceramic capacitor, a multilayer block in which a large number of capacitor structures are formed vertically and horizontally by a dielectric ceramic green sheet and an internal electrode paste. Slits for dividing each capacitor element unit are provided on one surface, the block is baked, all capacitor element sections on the slitted surface are marked with a marking paste so that the internal electrodes are exposed. The slits are divided in either the row or column direction of the slits, and each capacitor element column is divided into rows for external electrodes. A method for manufacturing a monolithic ceramic capacitor, characterized in that after forming an electrode by applying a strike and firing the electrode, a slit between elements is divided into individual capacitor element units for separation.