JPH08306578A - Manufacture of multilayer ceramic electronic part - Google Patents

Abstract

PURPOSE: To eliminate crack defect by baking a lamination body, then polishing a lamination body by using acid solution mixed with polishing material which causes the generation of hydrogen in alkaline solution and then forming an external electrode in an edge face of a lamination body. CONSTITUTION: A dielectric green sheet 1 having an element which shows alkaline when dissolved in water after baked and an inner electrode 2 containing palladium are laminated alternately and fixed by pressure, and a lamination body is prepared. Then, a lamination body is cut to a specified size and baked. Thereafter, a baked laminated ceramic capacitor element, silicon carbide powder which is a polishing material, polishing glass ball, water and acid solution whose pH is adjusted at 4 to 6 are put in a polishing pot. It is rotated for polishing. After polishing, an external electrode 3 is formed in both exposed surfaces of the inner electrode 2 of a multilayer ceramic capacitor element.

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 electronic component which is a kind of electronic component used in various electronic devices.

[0002]

2. Description of the Related Art The following is a conventional multilayer ceramic electronic component.
The manufacturing method will be described with reference to the drawings. In Figure 1,
A general monolithic ceramic capacitor is shown. First, Ba
TiO ₃Dielectric material mainly composed of, organic binder,
Plasticizer, dispersant, etc. were mixed and shaped on the film
After that, cut into a predetermined size and put the dielectric green sheet 1
create. Next, each chip of the dielectric green sheet 1 is
Use a conductive paste such as palladium in the area
, The conductor pattern that becomes the internal electrode 2 by screen printing
Form Next, the dielectric pattern with the conductor pattern is formed.
The inner electrode 2 is the dielectric green sheet 1 with the lean sheet 1
Are sandwiched in between so as to be alternately opposed to each other and stacked. That
After that, pressure bonding is performed to form a laminated body. Next, blade thickness 100μ
Use a cutter blade of about m to make the stack a predetermined size
Cut into pieces.

Next, the laminated body cut into chips is housed in a setter or the like and placed in a firing furnace for firing.

Next, the internal electrode 2 is exposed on the end face of this fired product, and polishing is performed for deburring. Therefore, in a pot of a predetermined size lined with rubber, the baked element, silicon carbide abrasive, polishing balls,
Add water and polish for tens of minutes to several hours. After that, the element and the abrasive are separated and dried, and the polishing process is completed. The external electrodes 3 are formed on the ends of the polished laminated body with silver paste or the like. After that, a plated layer is formed in the shape of the underlying conductor film, and the laminated ceramic capacitor element is completed.

[0005]

However, in the monolithic ceramic capacitor manufactured by the conventional technique, the crack defect 4 as shown in FIG. 2 has occurred. This is because during polishing of the end face of a monolithic ceramic capacitor, finely ground ceramic abrasion powder is dissolved in water to make the solution alkaline, which reacts with the impurities in the silicon carbide abrasive used in polishing to react with hydrogen gas. Occurs. As a result, there is a problem that the palladium used as the internal electrode absorbs hydrogen gas and expands to cause cracks.

Therefore, an object of the present invention is to provide a monolithic ceramic electronic component free from crack defects by preventing generation of hydrogen even when ceramic abrasion powder is melted out when polishing a fired laminate. To do.

[0007]

In order to achieve this object, a method of manufacturing a laminated ceramic electronic component according to the present invention comprises a dielectric green sheet having a component exhibiting an alkalinity when dissolved in water after firing and an inner portion containing palladium. The laminated body in which the electrodes are alternately laminated is fired, and then the laminated body is polished by using an acidic solution mixed with an abrasive that causes generation of hydrogen in an alkaline solution, and then the end face of the laminated body is externally exposed. It forms an electrode.

[0008]

According to this method, when polishing the laminated body after firing, even if the ceramic polishing powder dissolves in water, the pH does not change and the solution does not become alkaline because of the buffering action of the acidic solution. It is possible to prevent hydrogen gas from being generated by the reaction between the abrasive and the solution.

As a result, the internal electrode containing palladium does not expand and crack defects do not occur.

[0010]

【Example】

(Embodiment 1) Hereinafter, a first embodiment of the present invention will be described with reference to the drawings.

A slurry prepared by mixing a dielectric material containing barium titanate as a main component, an organic binder, a plasticizer, a dispersant, etc. is shaped on a film by a reverse roll method or the like to prepare a dielectric green sheet 1. To do. Next, a conductive pattern to be the internal electrodes 2 is formed by screen printing on the dielectric green sheet 1 in each chip region using palladium paste. next,
The dielectric green sheets 1 on which the conductor patterns are formed are arranged and laminated so that the internal electrodes 2 are alternately opposed to each other with the dielectric green sheets 1 sandwiched therebetween. Then, pressure bonding is performed to form a laminated body. Next, the laminate is cut into a predetermined size by using a cutter blade having a blade thickness of about 100 μm.

Next, the laminated body cut into a predetermined size is housed in a setter or the like and placed in a firing furnace for firing.

Next, the polishing step will be described. Multilayer ceramic capacitor element 10 fired in a polishing pot
000 pieces, 100 cc of silicon carbide powder as an abrasive, 300 cc of polishing glass balls, 500 cc of water, and 100 cc of 1N acetic acid adjusted to pH 6 are added. After that, the lid is covered and the pot is rotated for 1 hour to perform polishing. After the polishing, the element and the balls are separated, washed and dried to complete the polishing process.

For the polished monolithic ceramic capacitor element manufactured in this manner, the appearance selection is 1000
The results of performing 0 cracks and investigating the occurrence of cracks are shown in (Table 1).

[0015]

[Table 1]

As is clear from (Table 1), cracking is prevented by this manufacturing method.

(Second Embodiment) A second embodiment of the present invention will be described below with reference to the drawings.

First, a slurry prepared by mixing a dielectric material containing barium titanate as a main component, an organic binder, a plasticizer, a dispersant, etc. is shaped on a film by a reverse roll method or the like, and the dielectric green sheet 1 is formed. To create. Next, a conductive pattern to be the internal electrodes 2 is formed by screen printing on the dielectric green sheet 1 in each chip region using palladium paste.
Next, the dielectric green sheet 1 on which a conductor pattern is formed
Are laminated so that the internal electrodes 2 are alternately opposed to each other with the dielectric green sheet 1 interposed therebetween. Then, pressure bonding is performed to form a laminated body. Next, the laminate is cut into a predetermined size by using a cutter blade having a blade thickness of about 100 μm.

Next, the laminated body cut into a predetermined size is housed in a setter or the like and placed in a firing furnace for firing.

Next, the polishing process will be described. Multilayer ceramic capacitor element 10 fired in a polishing pot
000 pieces, 100 cc of silicon carbide powder as an abrasive, 300 cc of polishing glass balls, 500 cc of water, and 100 cc of 1N acetic acid whose pH is adjusted to 4 are added. After that, the lid is covered and the pot is rotated for 1 hour to perform polishing. After the polishing, the element and the balls are separated, washed and dried to complete the polishing process.

With respect to the polished monolithic ceramic capacitor element manufactured in this manner, the appearance was selected to 1000.
As is clear from the results (Table 1) in which 0 cracks were generated and the occurrence of cracks was investigated, the occurrence of cracks was prevented by this manufacturing method.

(Embodiment 3) A third embodiment of the present invention will be described below with reference to the drawings.

First, a slurry prepared by mixing a dielectric material containing barium titanate as a main component, an organic binder, a plasticizer, a dispersant, etc. is shaped on a film by a reverse roll method or the like, and the dielectric green sheet 1 is formed. To create. Next, a conductive pattern to be the internal electrodes 2 is formed by screen printing on the dielectric green sheet 1 in each chip region using palladium paste.
Next, the dielectric green sheet 1 on which a conductor pattern is formed
Are laminated so that the internal electrodes 2 are alternately opposed to each other with the dielectric green sheet 1 interposed therebetween. Then, pressure bonding is performed to form a laminated body. Next, the laminate is cut into a predetermined size by using a cutter blade having a blade thickness of about 100 μm.

Next, the laminated body cut into a predetermined size is housed in a setter or the like and placed in a firing furnace for firing.

Next, the polishing process will be described. Multilayer ceramic capacitor element 10 fired in a polishing pot
000 pieces, 100 cc of silicon carbide powder as an abrasive, 300 cc of polishing glass balls, 500 cc of water, and 100 cc of 1N acetic acid adjusted to pH 3 are added. After that, the lid is covered and the pot is rotated for 1 hour to perform polishing. After the polishing, the element and the balls are separated, washed and dried to complete the polishing process.

With respect to the polished monolithic ceramic capacitor element manufactured in this way, the appearance was selected to 1000.
The results of performing 0 cracks and investigating the occurrence of cracks are shown in (Table 1). As a result, it was revealed that the acid whose pH was adjusted to 3 did not cause cracks but the surface of the element was violated by the acid, and the acid could not be used at pH 3.

(Embodiment 4) A fourth embodiment of the present invention will be described below with reference to the drawings.

First, a slurry prepared by mixing a dielectric material containing barium titanate as a main component, an organic binder, a plasticizer, a dispersant and the like is shaped on a film by a reverse roll method or the like, and the dielectric green sheet 1 is formed. To create. Next, a conductive pattern to be the internal electrodes 2 is formed by screen printing on the dielectric green sheet 1 in each chip region using palladium paste.
Next, the dielectric green sheet 1 on which a conductor pattern is formed
Are laminated so that the internal electrodes 2 are alternately opposed to each other with the dielectric green sheet 1 interposed therebetween. Then, pressure bonding is performed to form a laminated body. Next, the laminate is cut into a predetermined size by using a cutter blade having a blade thickness of about 100 μm.

Next, the laminated body cut into a predetermined size is housed in a setter or the like and placed in a firing furnace for firing.

Next, the polishing process will be described. Multilayer ceramic capacitor element 10 fired in a polishing pot
Add 000 pieces, 100 cc of abrasive silicon carbide powder, 300 cc of polishing glass balls, 500 cc of water, and 100 cc of commercially available vinegar. Vinegar has an acidity of 4.2%,
A pH of 4 was used. After that, the lid is covered and the pot is rotated for 1 hour to perform polishing. After the polishing, the element and the balls are separated, washed and dried to complete the polishing process.

With respect to the polished laminated ceramic capacitor element manufactured in this manner, the appearance was selected to 1000.
The results of performing 0 cracks and investigating the occurrence of cracks are shown in (Table 1). As is clear from (Table 1), the generation of cracks is prevented by this manufacturing method.

In Examples 1 to 4, after the polishing step,
A multilayer ceramic capacitor is obtained by forming the external electrodes 3 on both exposed surfaces of the internal electrodes 2 of the multilayer ceramic capacitor element.

Further, although it is shown only when the acetic acid solution having a pH of 4 and 6 is added to water, any oxalic acid, hydrochloric acid, sulfuric acid or the like may be used as long as it is an acidic solution having a pH of 4 to 6. And
The mixing ratio may be such that the polishing liquid does not become alkaline until the end of the polishing step and hydrogen is not generated due to impurities contained in the polishing material.

The present invention can be easily carried out by using generally commercially available vinegar as shown in Example 4 without adjusting an acidic solution having a pH of 4 to 6.

Although palladium is used as the internal electrode 2 in Examples 1 to 4, the present invention is effective when a metal containing palladium such as silver-palladium is used as the internal electrode 2.

Further, in Examples 1 to 4, barium titanate was used as the material of the dielectric green sheet 1 and silicon carbide powder was used as the abrasive. However, ceramic powder showing alkalinity when dissolved in water was used as the material of the ceramic layer. In the polishing process, if the solution becomes alkaline, a multilayer ceramic electronic component that uses an abrasive material that may generate hydrogen can be used to obtain the same effect without being limited to the multilayer ceramic capacitor.

[0037]

As described above, according to the present invention, in the polishing process of a monolithic ceramic capacitor, by adding an acid in advance during polishing, the pH does not change even if the ceramic polishing powder dissolves in water during polishing. Since it does not become alkaline, the reaction with the polishing agent is suppressed, and hydrogen gas is not generated. Therefore, crack defects do not occur, and a monolithic ceramic capacitor having excellent reliability can be efficiently manufactured.

[Brief description of drawings]

FIG. 1 is a partially cutaway perspective view of a general monolithic ceramic capacitor.

FIG. 2 is a perspective view of a laminated body in which a crack defect occurs.

[Explanation of symbols]

 1 Dielectric green sheet 2 Internal electrode 3 External electrode

Claims (2)

[Claims] 1. A cause for producing hydrogen in an alkaline solution by firing a laminated body in which dielectric green sheets having a component showing alkalinity when dissolved in water after firing and internal electrodes containing palladium are alternately fired, and then hydrogen is generated in an alkaline solution. A method for manufacturing a laminated ceramic electronic component, comprising: polishing the laminate using an acidic solution mixed with an abrasive to be used, and then forming external electrodes on the end faces of the laminate. 2. The method for producing a laminated ceramic electronic component according to claim 1, wherein an acidic solution having a pH of 4 to 6 is used to form the acidic solution.