JPH08306579A - Manufacture of multilayer ceramic capacitor - Google Patents

Abstract

PURPOSE: To prevent the generation of a defective by restraining cut misregistration by mechanically detecting a step formed in a surface of a green lamination block, selecting a cut position based on this and cutting a raw lamination block along the cut position. CONSTITUTION: A plurality of ceramic green sheets 1 wherein a plurality of inner electrodes 2 are formed are laminated with a ceramic green sheet 1 wherein an inner electrode 2 is not formed therebetween and fixed by pressure by a rubber press for forming a green lamination block 1a. At the same time, a lattice-like step 11 is formed in a surface of the green lamination block 1a. The step 11 in a surface of the raw lamination block 1a is mechanically detected by using a surface roughness meter 12, etc., and a position of a cut line 13, that is, a cut position is selected at a central point or a lowest point of a recessed step. Then, a green capacitor lamination body is cut along a cut line 13.

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, and more specifically, cutting out a raw capacitor laminate from a raw laminate block formed by laminating and pressure-bonding ceramic green sheets provided with internal electrodes. It is about the method for.

[0002]

2. Description of the Related Art Generally, in a method for manufacturing a monolithic ceramic capacitor, individual capacitor laminates are obtained by cutting out from a raw laminate block. The cutting out method is the same as the method for producing a monolithic ceramic capacitor described below. I will explain in the inside.

First, as shown in FIG. 4, a ceramic green sheet 10 is prepared. Then, a plurality of matrix-shaped internal electrodes 20 are formed in the central portion of the ceramic green sheet 10, and cut marks 30 are applied to the peripheral portion of the ceramic green sheet 10 by screen printing or the like. The cut marks 30 are used when cutting from a later-described raw laminate block into individual capacitor laminates. The number of internal electrodes 20 is not limited to nine shown in the figure. Next, a predetermined number of ceramic green sheets 10 on which the plurality of internal electrodes 20 are formed are stacked, and an appropriate number of ceramic green sheets 10 on which the internal electrodes 20 are not formed are stacked on top and bottom of the stacked ceramic green sheets 10 and pressure-bonded to form a raw stack. Get a body block. Then, as shown in FIG. 5, the peripheral portion of the raw laminate block 10a is cut so that the cut mark 30 is exposed, and the cut line is determined from the cut mark 30 exposed in the cut section.
Along the cutting line, cutting is performed by a cutter or the like to obtain individual raw capacitor laminated bodies. Then, the raw capacitor laminate is fired to obtain a capacitor element. Then, an external electrode paste is applied to both end faces of this capacitor element and fired to form external electrodes, thereby producing a monolithic ceramic capacitor.

[0004]

However, the cut marks 30 exposed on the end faces of the peripheral portion of the raw laminate block as described above are stacked in the stacking direction as shown in FIG. It is not perpendicular to the surface, but it is curved or misaligned from side to side. This is cut mark 3
This is caused by stacking displacement of the ceramic green sheets, pressure distortion, etc. when a plurality of ceramic green sheets on which 0 is formed are stacked and pressure-bonded. For this reason,
It was difficult to determine an accurate cut line from the cut mark 30 that is curved or is shifted from side to side. As a result, there is a problem in that the cutting position is displaced, and the internal electrode 20 is exposed on the side surface of the cut raw capacitor laminate 40 as shown in FIG.

Therefore, the present invention has been made to solve the above problems, and an object of the present invention is to provide a method for manufacturing a monolithic ceramic capacitor which can prevent a defective product from occurring by suppressing a positional deviation of a cut. And

[0006]

According to the present invention, a step of forming a plurality of internal electrodes on a ceramic green sheet in a matrix form, and a plurality of ceramic green sheets having the plurality of internal electrodes formed thereon are provided. Sandwiching between the ceramic green sheets in which the green is not formed, stacking and pressing with a rubber press to form a raw laminate block, and at the same time forming a grid-like step on the surface of the raw laminate block; Mechanically detecting the surface step of the laminated block, determining the cut position at the center point or the lowest point of the step based on this, and cutting the raw laminated block at this cut position. And a method for manufacturing a monolithic ceramic capacitor.

[0007]

In the present invention, a plurality of ceramic green sheets on which a plurality of matrix-shaped internal electrodes are formed are stacked and pressure-bonded by a rubber press. This creates a grid-like step on the surface of the green stack block between the individual capacitor stacks within that block. The level difference formed on the surface of this raw laminate block is mechanically detected using a surface roughness meter, etc., the cutting position is determined based on this, and the raw laminate block is located along that cutting position. To cut out a raw capacitor laminate. Therefore, the individual capacitor laminated bodies in the block can be cut out without deviation of the cutting position.

[0008]

Embodiments of the present invention will be described below with reference to FIGS.

First, as shown in FIG. 1, for example, Ag / P
A conductive paste made of d alloy is applied by screen printing or the like to produce a ceramic green sheet 1 in which a plurality of internal electrodes 2 are formed in a matrix. The number of internal electrodes 2 is not limited to nine shown in FIG.
In reality, a large number are formed.

Next, a predetermined number of ceramic green sheets 1 having the plurality of internal electrodes 2 formed thereon are stacked, and an appropriate number of ceramic green sheets 1 having no internal electrodes 2 formed thereon are stacked.

Thereafter, the stacked ceramic green sheets 1 are pressure-bonded by a rubber press to form a green laminate block 1a shown in FIG. 2 (a).

In the crimping by the rubber press, for example, the laminated body of the stacked ceramic green sheets 1 is sandwiched by rubber, and pressure is applied uniformly in the laminating direction to crimp.

By applying pressure by the rubber press as described above, the raw laminate block 1a is formed, and at the same time, the surface of the raw laminate block 1a is covered with the individual capacitor laminates in the block. Lattice-shaped steps 1 between
1 is formed. That is, when a plurality of ceramic green sheets 1 each having a plurality of internal electrodes 2 formed thereon are laminated, a difference in the total thickness of the lamination is generated between a portion having the internal electrodes 2 and a portion not having the internal electrodes 2. As a result, in the raw laminate block to which the rubber press is added, the surface of the portion without the internal electrode 2 is recessed, as shown in FIG.
2A which is a cross-sectional view of the raw laminate block 1a of FIG. 2A at the position of the line X-X, as shown in FIG. 2B, a step 11 is formed between the portion with the internal electrode 2 and the portion without the internal electrode 2. To be done.

A step 11 is formed on the raw laminate block 1a.
Means for forming, in addition to the rubber press as described above,
It may be formed by a hydrostatic rubber press. Further, in the case of pressing with hydrostatic pressure, it is not always necessary to use a rubber, and the hydrostatic pressure may directly affect the laminate block, and it is added that such a method is also included in the scope of the present invention. Keep it.

Next, the raw capacitor laminate is cut from the press-molded raw laminate block 1a along the cut line 13 with a cutter or the like. Prior to this cutting, as shown in FIG. 2C, the surface of the raw laminate block 1a is scanned using a surface roughness meter 12 or the like to mechanically detect a step 11 on the surface, and Based on the above, the cut position is determined at the position of the cut line 13, that is, the center point or the lowest point of the concave step.

Next, the raw capacitor multilayer body 4 thus cut out is fired, and then external electrodes are applied to both end faces of the internal electrode 2 which are led out and baked, whereby a monolithic ceramic capacitor is manufactured. It

As described above, by stacking a plurality of ceramic green sheets having a plurality of matrix-shaped internal electrodes formed thereon and pressing them with a rubber press, a step 11 is formed.
Are formed in a grid pattern on the surface of the green stack block between the individual capacitor stacks within the block. Then, the position of the cut line 13 is determined based on this step 11. Therefore, the cut position is unlikely to be displaced, and thus the defective exposure of the internal electrodes of the cut raw capacitor multilayer body 4 can be reduced.

Next, in order to confirm the effectiveness of the method for manufacturing a multilayer capacitor of the present invention, the following experiment was conducted. First, according to the manufacturing method of the above example, 10,000 raw capacitor laminated bodies were manufactured. Next, the produced capacitor laminated body was visually observed to check for defective internal electrode exposure. As a result, no defective exposure of the internal electrodes was observed.
Further, the defective exposure of the internal electrodes of the raw capacitor laminate manufactured by the conventional manufacturing method was examined. As a result, 5% of the internal electrode exposure defects occurred.

From the above results, it can be seen that the raw capacitor laminate manufactured by the manufacturing method of the present invention can reduce defective internal electrode exposure as compared with the conventional one.

[0020]

As described above, according to the present invention, it is possible to eliminate the defective exposure of the internal electrodes of the cut out raw capacitor multilayer body 4 and to obtain a highly reliable multilayer ceramic capacitor.

[Brief description of drawings]

FIG. 1 is a ceramic green sheet used in the manufacturing method of the present invention.

FIG. 2 is an explanatory diagram of a step of determining a cutting position in the manufacturing method of the present invention.

FIG. 3 is a perspective view of a raw capacitor laminate manufactured by the manufacturing method of the present invention.

FIG. 4 is a ceramic green sheet used in a conventional manufacturing method.

FIG. 5 is a perspective view of a raw laminate block manufactured by a conventional manufacturing method.

FIG. 6 is a perspective view of a raw capacitor laminate in which the cutting position is displaced.

[Explanation of symbols]

 1 ... Ceramic green sheet 1a ... Raw laminate block 2 ... Internal electrode 11 ... Step 12 ... Surface roughness meter 13 ... Cut line

Claims (1)

[Claims] 1. A step of forming a plurality of internal electrodes in a matrix shape on a ceramic green sheet, and a plurality of ceramic green sheets having the plurality of internal electrodes formed therein, and a ceramic green sheet having no internal electrodes formed therein. Sandwiching between sheets, stacking and pressing with a rubber press to form a raw laminate block, and at the same time forming a grid-like step on the surface of the raw laminate block; and a surface step on the raw laminate block. A mechanical step of determining the cutting position at the center point or the lowest point of the step based on this, and cutting the raw laminated body block at this cutting position. Manufacturing method.