JPH09190948A - Manufacture of stacked ceramic electronic element - Google Patents

Abstract

PROBLEM TO BE SOLVED: To see that an inner electrode may not be dislocated in the face direction, by executing press process in condition that sheets for press which show larger elasticity in thickness direction than in face direction are piled up with a stack between. SOLUTION: A plurality of ceramic green sheets 1 where inner electrodes 3 are made are arranged in the middle, and besides a plurality of ceramic green sheets 2 where inner electrodes 3 are not made are arranged outside, and in that condition they are piled up to get a stack 4. This stack 4 is, next, put in a mold 5, and are pressed in thickness direction in condition that it is caught from above and below by sheets 12 for press, by pressing a punch 6 toward the mold 5 as shown by an arrow 7. At this time, the sheet 12 for press shows larger elasticity in thickness direction than in face direction.

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 multilayer ceramic electronic component, and more particularly to an improvement in a step of pressing a plurality of stacked ceramic green sheets.

[0002]

2. Description of the Related Art For example, when manufacturing a multilayer ceramic electronic component such as a multilayer ceramic capacitor,
A plurality of ceramic green sheets are prepared, these ceramic green sheets are stacked and then pressed. Internal circuit elements such as internal electrodes for forming capacitors, resistors, inductors, varistors, filters, etc. are formed on a specific ceramic green sheet according to the function of the monolithic ceramic electronic component to be obtained. There is.

FIG. 3 shows a pressing process carried out for manufacturing a monolithic ceramic capacitor, for example. As shown in FIG. 3, a plurality of ceramic green sheets 1 and 2 are prepared, and an internal electrode 3 as an internal circuit element is formed on a specific ceramic green sheet 1 among these ceramic green sheets 1 and 2. It These ceramic green sheets 1 and 2
Are stacked with the plurality of ceramic green sheets 1 having the internal electrodes 3 arranged in the middle and the plurality of ceramic green sheets 2 having no internal electrodes 3 arranged on the outside, and thus stacked. Body 4 is obtained.

The laminated body 4 is inserted into the mold 5, and then the punch 6 is fitted into the mold 5, and the punch 6 is pressed toward the mold 5 as shown by an arrow 7. by this,
The laminated body 4 is pressed in the thickness direction. The pressed laminate 4 is then cut in order to obtain laminate chips for individual monolithic ceramic capacitors, these laminate chips are fired and the steps for forming external electrodes are carried out. A desired monolithic ceramic capacitor can be obtained.

[0005]

However, the following problems may be encountered in the above-mentioned pressing process. That is, in the stacked body 4, the portion where the internal electrodes 3 overlap is thicker than the portion where the internal electrodes 3 do not overlap. Therefore, the pressing action in the pressing process is greater in the portion where the internal electrodes 3 overlap in the stacking direction than in the portion that does not. , Is more strongly exerted on the laminate 4. As a result, the pressing action is not uniformly exerted in the plane direction of the laminate 4, and accordingly, a force for moving the material of the portion exerting a strong pressing action to the portion having a weak pressing action is generated in the laminate 4. .

Therefore, as shown in FIG. 4 (a) or (b), in the laminated chip 8 obtained after pressing,
The internal electrodes 3 may be misaligned 9 or 10 in the plane direction, which may lead to structural defects in the obtained monolithic ceramic capacitor. In addition, in order to solve such problems,
As shown in FIG. 3, an elastic sheet 11 made of, for example, rubber is inserted between the laminated body 4 and each of the mold 5 and the punch 6 to reduce the above-mentioned difference in pressing action. There is. However, when the elastic sheet 11 is deformed in the thickness direction, the elastic sheet 11 is also deformed in the surface direction. Therefore, the positional deviation 9 in the surface direction of the internal electrode 3 as described above is caused.
Or 10 cannot be suppressed sufficiently.

Therefore, an object of the present invention is to provide a method for manufacturing a monolithic ceramic electronic component which can solve the above-mentioned problems.

[0008]

According to the present invention, a plurality of ceramic green sheets are prepared, internal circuit elements are formed on specific ones of the plurality of ceramic green sheets, and the plurality of ceramic green sheets are stacked. Obtain a laminate, press this laminate in the thickness direction,
The present invention is directed to a method for manufacturing a monolithic ceramic electronic component including each step, and is characterized by having the following configuration in order to solve the above technical problem.

That is, according to the present invention, a press sheet having greater elasticity in the thickness direction than in the plane direction is prepared, and the press sheets are stacked above and below the laminate, The pressed step is performed. As the press sheet that is a feature of the present invention, for example, a resin sheet in which a plurality of cavities whose surface dimension is longer than that in the thickness direction are distributed is used.

[0010]

Since the pressing sheet used in the present invention exhibits greater elasticity in the thickness direction than in the surface direction, it may expand in the surface direction with shrinkage in the thickness direction. It can be suppressed. Therefore, according to the present invention, by stacking such pressing sheets on the upper and lower sides of the laminate to be pressed and carrying out the pressing step, the difference in thickness between the portion where the internal circuit elements overlap and the portion where the internal circuit elements do not overlap is increased. Not only can the pressing sheet absorb the difference in the pressing action based on the above, but the pressing sheet can be prevented from spreading in the surface direction, so that the pressing action is strongly exerted in the laminate. It is also possible to prevent the material of the part to be moved from moving to a part where the pressing action is weak.

As a result, the displacement of the internal circuit elements can be suppressed, and the yield rate of the obtained monolithic ceramic electronic component can be increased.

[0012]

1 is a view corresponding to FIG. 3 for explaining a method of manufacturing a monolithic ceramic electronic component according to an embodiment of the present invention. In order to facilitate comparison between FIG. 1 and FIG. 3, in FIG. 1, elements corresponding to those shown in FIG. 3 are designated by similar reference numerals. This embodiment also intends to manufacture a monolithic ceramic capacitor as a monolithic ceramic electronic component.

Referring to FIG. 1, as in the case shown in FIG. 3, a plurality of ceramic green sheets 1 and 2 are prepared. Of these ceramic green sheets 1 and 2, a particular ceramic green sheet 1 is placed on a specific ceramic green sheet 1. , The internal electrode 3 as an internal circuit element is formed. These ceramic green sheets 1 and 2 have a plurality of ceramic green sheets 1 having internal electrodes 3 arranged in the middle and a plurality of ceramic green sheets 2 having no internal electrodes 3 arranged outside. , Stacked, whereby a laminate 4 is obtained.

The laminated body 4 is then inserted into the mold 5. For this insertion, a pressing sheet 12 is prepared, and these pressing sheets 12 are stacked above and below the laminated body 4, respectively. Be done. The pressing sheet 12 is enlarged and shown in a sectional view in FIG. With reference to FIG. 2, the press sheet 12 is made of a resin material such as synthetic resin or natural rubber. The press sheet 12 has a plurality of cavities 13 whose inner dimension in the plane direction is longer than that in the thickness direction. These cavities 13 form several layers in the press sheet 12. In this way, the press sheet 12
Shows greater elasticity in the thickness direction than in the plane direction.

As an example, the pressing sheet 12 is made of a polyethylene terephthalate sheet and has a thickness of, for example, about 200 μm. Further, one cavity 13 has, for example, a dimension in the thickness direction of 10
It is about 20 μm, and the surface dimension is about 100 μm. The volume ratio of the cavities 13 in the pressing sheet 12 is, for example, about 20%.

Since the pressing sheet 12 may come into contact with and adhere to the ceramic green sheet 2 during pressing, it is possible to easily release the pressing sheet 12 from the ceramic green sheet 2 after pressing. It is preferable to have a property. Therefore, it is preferable that the press sheet 12 is made of a material having excellent mold releasability or is surface-treated so as to give excellent mold releasability.

Referring again to FIG. 1, the laminated body 4 inserted into the mold 5 in a state of being sandwiched from above and below by such a press sheet 12 has a punch 6 as shown by an arrow 7. By pressing toward the die 5, the die 5 is pressed in the thickness direction. At this time, since the pressing sheet 12 exhibits greater elasticity in the thickness direction than in the surface direction, the pressing action based on the difference in thickness between the portion where the internal electrodes 3 overlap and the portion where the internal electrode 3 does not overlap. In order to absorb the difference in the thickness, the material can be shrunk in the thickness direction, but the expansion in the surface direction can be suppressed accordingly, so that the material of the portion where the pressing action is strongly exerted in the laminated body 4 becomes a portion where the pressing action is weak. Suppress movement. As a result, the internal electrode 3
The positional deviation of is advantageously suppressed.

Next, the laminated body 4 pressed in this way
As in the conventional case described above, cutting is performed to obtain a laminated chip for each monolithic ceramic capacitor, these laminated chips are fired, and steps for forming external electrodes are performed. A desired monolithic ceramic capacitor can be obtained. In order to confirm the effect of this invention, the following experiment was tried.

In FIG. 1, ceramic green sheets 1 and 2 having a thickness of 18 μm were prepared. Of these, 3μ is on the ceramic green sheet 1.
An internal electrode 3 made of a conductive paste having a thickness of m was formed by screen printing. Internal electrode 3 formed 5
0 ceramic green sheets 1 and ceramic green sheets 2 not having the internal electrodes 3 formed thereon, each having a thickness of 150 μm, are stacked on the outside thereof to form a laminated body 4
I got

In the mold 5, first, the volume ratio of the cavity 13 is 20.
%, A pressing sheet 12 made of polyethylene terephthalate having a thickness of 200 μm is inserted, then the above-mentioned laminate 4 is inserted, and further, the same pressing sheet 12 is inserted, and then the punch 6 is fitted to perform the pressing step. Carried out.
On the other hand, as a comparative example, the same pressing process was performed except that the above-mentioned pressing sheet 12 was not used.

The positional deviation 9 or 10 of the internal electrode 3 shown in FIG. 4A or 4B was measured for the laminated chip 8 obtained through these pressing steps. In the comparative example, the positional deviation was found. Average value is 92μm, maximum value is 16
The average value of the positional deviation was 31 μm when the pressing sheet 12 was used according to the present invention.
m, and the maximum value was reduced to 75 μm.

The present invention has been described above mainly with reference to the method for manufacturing a monolithic ceramic capacitor. However, the present invention is not limited to monolithic ceramic capacitors, and monolithic ceramic electronic parts functioning as resistors, inductors, varistors, filters, etc. Moreover, the present invention can be applied to a monolithic ceramic electronic component in which these functional elements are combined.

Therefore, various modes are conceivable for the internal circuit element, and in addition to the circuit element having good conductivity such as the internal electrode, for example, a relatively large electric resistance or other electric characteristics can be obtained. It may be a circuit element that it has.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view showing a pressing step performed in manufacturing a monolithic ceramic capacitor as a monolithic ceramic electronic component according to an embodiment of the present invention.

FIG. 2 is an enlarged cross-sectional view showing a part of the press sheet 12 shown in FIG.

FIG. 3 is a view corresponding to FIG. 1, showing a pressing step performed in conventional manufacturing of a laminated ceramic capacitor.

FIG. 4 is a cross-sectional view showing a state in which a positional deviation 9 or 10 occurs in an internal electrode 3 in a laminated body chip 8.

[Explanation of symbols]

 1, 2 Ceramic green sheet 3 Internal electrode 4 Laminated body 5 Mold 6 Punch 12 Press sheet 13 Cavity

Claims (2)

[Claims] 1. A plurality of ceramic green sheets are prepared, internal circuit elements are formed on specific ones of the plurality of ceramic green sheets, and the plurality of ceramic green sheets are stacked to obtain a laminated body. Pressing in the thickness direction, each step is provided,
In the method for manufacturing a monolithic ceramic electronic component, a pressing sheet having greater elasticity in the thickness direction than in the surface direction is prepared, and the pressing sheets are stacked above and below the laminated body. Further, the method of manufacturing a laminated ceramic electronic component is characterized in that the pressing step is performed in a state in which the pressing sheets are stacked above and below the laminated body. 2. The method for manufacturing a monolithic ceramic electronic component according to claim 1, wherein the pressing sheet includes a resin sheet in which a plurality of cavities having a planar dimension longer than a thickness dimension are distributed inside. .