JP3528703B2 - Method for producing ceramic green sheet laminate - Google Patents

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 ceramic green sheet laminated body, and more particularly to a method for laminating a ceramic green sheet carried out in the process of manufacturing a laminated ceramic electronic component such as a laminated ceramic capacitor. It is a thing.

[0002]

2. Description of the Related Art When manufacturing a monolithic ceramic electronic component such as a monolithic ceramic capacitor,
A plurality of ceramic green sheets are prepared, the ceramic green sheets are stacked, and then the stacked plurality of ceramic green sheets are pressed in the stacking direction. In addition, on the specific ceramic green sheets to be stacked as described above, internal electrodes such as internal electrodes for forming capacitors, inductors, varistors, filters, etc. are formed according to the function of the monolithic ceramic electronic component to be obtained. A conductor film is formed.

[0003]

In order to obtain a laminated ceramic electronic component with good quality, it is necessary to prevent air from being taken in between the adjacent ceramic green sheets of the ceramic green sheet laminate as described above. It is important to. Undesirably, if air is taken in, this air will cause structural defects such as delamination and cracks in the sintered laminate obtained by firing the ceramic green sheet laminate. is there.

The above-mentioned air is mainly taken in between the adjacent ceramic green sheets when stacking the ceramic green sheets, but normally, a step of pressing a plurality of stacked ceramic green sheets in the stacking direction. In, the sheet is discharged from between the adjacent ceramic green sheets. When this air is discharged, a main air passage is formed between the internal conductor films formed so as to be distributed at a plurality of locations on the main surface of the ceramic green sheet.

However, in the pressing process as described above, the discharge of air may not proceed smoothly. In particular, in order to realize miniaturization and high performance in a monolithic ceramic electronic component, for example, in the case of a monolithic ceramic capacitor, in order to achieve miniaturization and high capacity, thinning of the ceramic green sheet and As the number of layers increases, it becomes more difficult to discharge such air. Further, even when the size of the ceramic green sheet is increased to, for example, 300 mm square or more, the air discharge in the central portion is deteriorated.

In order to make air discharge more complete, a degassing step is provided before the pressing step, or the pressing step is performed while degassing, so that the air between the adjacent ceramic green sheets can be removed. Although it may be considered that the air is discharged from the gap between the adjacent ceramic green sheets, particularly the gap between the internal conductor films, it is still difficult to achieve the perfect discharge of air even if such means is adopted.

Therefore, an object of the present invention is to provide a method for manufacturing a ceramic green sheet laminate which can achieve more perfect air discharge as described above.

[0008]

According to the present invention, there are provided a step of preparing a plurality of ceramic green sheets, a step of stacking a plurality of ceramic green sheets, and a step of pressing a plurality of stacked ceramic green sheets in a stacking direction. And a step of providing a through hole in the ceramic green sheet in order to solve the above-mentioned technical problem. In the above, the air between the adjacent ceramic green sheets is discharged by sucking through the through holes.

In the first preferred embodiment of the present invention, a plurality of ceramic green sheets having through holes are prepared, and the ceramic green sheets having such through holes are stacked one by one. It Then, by sucking through the through holes, air between the adjacent ceramic green sheets is discharged, and the ceramic green sheets stacked as described above are pressed in the stacking direction.

Furthermore, in the first preferred embodiment described above, when stacked cell La Mick green sheet, by the holding head, while maintaining a single ceramic green sheet, as stacked already stacked ceramic green sheets To be done. At this time, the holding head has a suction port communicating with a through hole provided in the ceramic green sheet, and in the pressing step,
Aligned so that the suction port communicates with the through hole
Then , the stacked ceramic green sheets are pressed by the holding head while exerting a suction action from the suction port.

In a second preferred embodiment of the invention,
A plurality of ceramic green sheets are prepared, the plurality of ceramic green sheets are stacked, and then a through hole is provided so as to penetrate the plurality of stacked ceramic green sheets. Then, by sucking air through the through holes, the plurality of stacked ceramic green sheets are pressed in the stacking direction while discharging the air between the adjacent ceramic green sheets.

In the present invention, when the internal conductor film is formed so as to be distributed in a plurality of locations on the main surface of the ceramic green sheet, the through hole described above does not have such an internal conductor film formed therein. It is preferably located in the area.

[0013]

1 is a plan view showing a ceramic green sheet 1 applied in a method for manufacturing a ceramic green sheet laminate according to an embodiment of the present invention.

On the ceramic green sheet 1, internal conductor films 2 are formed so as to be distributed at a plurality of locations on the main surface thereof. These internal conductor films 2 are to be internal electrodes in a laminated ceramic capacitor, for example, and are formed by applying a conductive paste by screen printing or the like.

In FIG. 1, only 15 internal conductor films 2 are shown for ease of illustration. However, in actuality, one ceramic green sheet 1 is further provided. Many internal conductor films 2 are often formed.

A plurality of through holes 3 are provided in such a ceramic green sheet 1. Each through hole 3 is preferably distributed so as to be located in a region where internal conductor film 2 is not formed. In this embodiment, the through holes 3 are
It is distributed at an intermediate position between the adjacent inner conductor films 2. The through hole 3 can be formed by a method such as laser, punch, or drill.

As an example, in this embodiment, the ceramic green sheet 1 has a thickness of 0.5 to 3 after firing.
μm, and the thickness of the internal conductor film 2 after firing is 0.6 to
It is 1.2 μm. Also, ceramic green sheet 1
Although the planar shape of the through-hole 3 provided in is not limited to a circular shape, when the planar shape of the through-hole 3 is a circular shape, the diameter thereof is, for example, 200 to 300 μm.

The ceramic green sheets 1 provided with the internal conductor film 2 and the through holes 3 in this manner are then stacked and pressed. The stacking step and the pressing step will be described with reference to FIG.

In FIG. 2, the holding head 4 and the stacking table 5 are shown.

The holding head 4 holds the ceramic green sheet 1 on the holding surface 6, and the holding surface 6 is provided with a plurality of first and second suction ports 7 and 8, respectively. ing. A negative pressure for exerting a suction action is applied to these suction ports 7 and 8. Further, the second suction port 8 is located so as to communicate with the through hole 3 provided in the ceramic green sheet 1. The first suction port 7 is located at a position other than the position where the through hole 3 is provided, and functions to suck the ceramic green sheet 1 onto the holding surface 6 based on vacuum suction.

Since the ceramic green sheet 1 is held on the holding surface 6, the ceramic green sheet 1 itself does not have to be vacuum-sucked through the first suction port 7 as described above, but may be adhered by the ceramic green sheet 1 itself. Good.

The stacking table 5 is used for positioning the stacked ceramic green sheets 1, and the mounting surface 9 thereof has a plurality of third and third applying negative pressures as in the case of the holding head 4. Fourth suction ports 10 and 11 are provided. The fourth suction port 11 is located so as to communicate with the through hole 3 provided in the ceramic green sheet 1. On the other hand, the third suction port 10 is located at a position other than the position where the through hole 3 is provided, and has a function of positioning the stacked ceramic green sheets 1 by suctioning based on vacuum suction.

FIG. 2A shows a state in which one ceramic green sheet 1 is held by a holding head 4, and a plurality of ceramic green sheets already stacked on the stacking table 5. 1 is shown. Note that, among the plurality of ceramic green sheets 1 on the stacking table 5, some of the ceramic green sheets 1 on the mounting surface 9 side have no internal conductor film formed thereon.

From the state shown in FIG. 2A, the holding head 4
Moves downward to realize the state shown in FIG. 2 (2), and a plurality of already stacked ceramic green sheets 1
On top of this, one ceramic green sheet 1 held by the holding head 4 is stacked.

Next, from the state shown in FIG. 2 (2), the holding head 4 is further moved downward, and the plurality of stacked ceramic green sheets 1 are pressed in the stacking direction. At this time, since the suction action is exerted from the second and fourth suction ports 8 and 11 described above, the air between the adjacent ceramic green sheets 1 is sucked so as to be positively discharged through the through hole 3. It
Therefore, it is advantageously prevented that air undesirably remains between the adjacent ceramic green sheets 1.

Then, the suction action exerted on the first and second suction ports 7 and 8 is released, and only the holding head 4 moves upward. Further, the holding head 4 moves to a position (not shown) at which the next prepared ceramic green sheet 1 can be held, and in the state where the next ceramic green sheet 1 is held, the holding heads 4 (1) and (2) are formed. The step shown in 2) and the subsequent pressing step are repeated.

The ceramic green sheet laminate obtained by stacking and pressing the desired number of ceramic green sheets 1 on the stacking table 5 is further subjected to final pressing, if necessary. After that, it is cut to obtain a monolithic ceramic electronic component such as an individual monolithic ceramic capacitor.
In this cutting step, the ceramic green sheet laminate is preferably cut so as to remove the portion where the through hole 3 is provided.

In the final pressing described above, this may be carried out on the stacking table 5, or the ceramic green sheet laminate may be put in another mold and a rigid press or a hydrostatic press may be applied. You may do it.

Although not shown in FIGS. 1 and 2,
The ceramic green sheet 1 may be handled while being lined with a carrier film. In this case, the carrier film is also provided with a through hole communicating with the through hole 3. The carrier film is shown in FIG.
When the pressing process after the stage shown in (2) is completed, this is peeled off.

Further, in the embodiment shown in FIG. 2, in the stacking table 5, the suction port 11 communicating with the through hole 3 is formed.
However, if the holding head 4 is provided with a similar suction port 8, such a suction port 11 may be omitted. In this case, it is not necessary that the through holes 3 be provided in the lowermost one of the stacked ceramic green sheets 1.

[0031]

FIG. 3 is for explaining another embodiment of the present invention.

FIG. 3 shows a state in which a plurality of prepared ceramic green sheets 1 are stacked. In this embodiment, after stacking a plurality of ceramic green sheets 1 having no through holes, the through holes 3 are provided so as to penetrate the plurality of ceramic green sheets 1 thus stacked. . For forming the through hole 3, for example, a laser may be used in addition to the drill 12 shown in the figure.

When stacking a plurality of ceramic green sheets 1 as shown in FIG. 3, a holding head 4 and a stacking table 5 as shown in FIG. 2 can be used, for example.

In this case, the surface plate 13 shown in FIG. 3 corresponds to the stacking table 5, and the second suction port 8 provided in the holding head 4 and the fourth suction port 11 provided in the stacking table 5. Is the first and third suction ports 7 and 8
Similar to the above, the ceramic green sheet 1 acts to be adsorbed. Further, when the holding head 4 is used in this way, it is provisionally pressed every time the ceramic green sheets 1 are stacked apart from the pressing step after the through hole 3 is provided.

Then, the plurality of stacked ceramic green sheets 1 are pressed in the stacking direction while discharging the air between the adjacent ceramic green sheets 1 by sucking through the through holes 3 described above. The target ceramic green sheet laminate is obtained.

As described above, the holding head 4 and the stacking table 5 shown in FIG. 2 are also used in the step of pressing the plurality of stacked ceramic green sheets 1 in the stacking direction while sucking through the through holes 3. be able to.

[0038]

As described above, according to the present invention, the through holes are provided in the ceramic green sheets, and when the pressing process is performed, the air between the adjacent ceramic green sheets is discharged by sucking through the through holes. Therefore, it is possible to prevent air from remaining between the ceramic green sheets, and therefore, in the sintered laminate obtained by firing the ceramic green sheet laminate manufactured according to the method of the present invention, It is possible to prevent structural defects such as lamination and cracks from occurring, and therefore, it is possible to enhance the reliability of the monolithic ceramic electronic component formed of the sintered laminated body.

In the present invention, a plurality of prepared ceramic green sheets are provided with through holes in advance, the ceramic green sheets having such through holes are stacked one by one, and then sucked through the through holes. Thus, by discharging the air between the adjacent ceramic green sheets and pressing the stacked ceramic green sheets one by one in the stacking direction as described above, the air between the adjacent ceramic green sheets can be discharged. Will be easier to do.

Further, in the above-mentioned embodiment, the holding head provided with the suction port communicating with the through hole is used, and while holding one ceramic green sheet by this holding head, the ceramic green sheets already stacked are stacked. In the step of stacking and then pressing, the holding head presses the stacked ceramic green sheets while exerting a suction action from the suction port, which facilitates the transition from the stacking step to the pressing step. At the same time, the suction action from the suction port can be surely exerted so that the air between the adjacent ceramic green sheets is discharged.

On the other hand, in the present invention, after stacking a plurality of ceramic green sheets, a through hole is provided so as to penetrate through the plurality of ceramic green sheets, and suction is performed through the through holes, thereby adjoining ceramics. While exhausting the air between the green sheets,
By pressing a plurality of stacked ceramic green sheets in the stacking direction, it is possible to discharge air between adjacent ceramic green sheets between a plurality of sets of adjacent ceramic green sheets at once. The ceramic green sheet laminate can be efficiently manufactured.

Further, in the present invention, when the internal conductor film is formed so as to be distributed in a plurality of locations on the main surface of the ceramic green sheet, through holes are formed in the regions where such internal conductor film is not formed. When positioned, not only can a part of the inner conductor film be prevented from being chipped by the through hole, but also smooth flow of the discharged air can be guaranteed up to the final stage of the press. This is because the gap between the inner conductor films can serve as an air passage until the final stage of pressing.

[Brief description of drawings]

FIG. 1 is a plan view showing a ceramic green sheet 1 applied in a method for manufacturing a ceramic green sheet laminate according to an embodiment of the present invention.

FIG. 2 is a view for explaining a stacking process and a pressing process performed for manufacturing a ceramic green sheet laminate using the ceramic green sheet 1 shown in FIG. It is sectional drawing which shows 1, the holding head 4, and the stacking table 5.

FIG. 3 is a cross-sectional view illustrating another embodiment of the present invention, showing a plurality of stacked ceramic green sheets 1.

[Explanation of symbols]

1 Ceramic green sheet 2 Internal conductor film 3 through holes 4 holding head 8 suction port 12 drills

Continuation of front page (58) Fields surveyed (Int.Cl. ⁷ , DB name) H01G 4/00-17/00

Claims (3)

(57) [Claims] 1. A step of preparing a plurality of ceramic green sheets having through holes, and a step of preparing the ceramic green sheets having the through holes.
Stacking the sheets one by one, and sucking air through the through holes to discharge air between the adjacent ceramic green sheets,
Pressing the ceramic green sheets stacked in the stacking direction in a stacking direction , wherein the stacking step is performed by a holding head.
While holding the ceramic green sheets,
Stacked on the stacked ceramic green sheets
The holding head communicates with the through hole.
The suction port is provided in the step of pressing.
In the state of being aligned so as to communicate with the through hole,
While holding the suction action from the suction port, the holding head
By said ceramic green sea stacked
A method for manufacturing a ceramic green sheet laminate, which comprises a step of pressing a sheet . 2. A step of preparing a plurality of ceramic green sheets, a step of stacking a plurality of the ceramic green sheets, and a step of providing a through hole so as to penetrate the plurality of stacked ceramic green sheets. And while sucking air through the through holes to discharge air between the adjacent ceramic green sheets,
And a step of pressing a plurality of the stacked ceramic green sheets in a stacking direction. 3. The ceramic green sheet is formed with an internal conductor film so as to be distributed at a plurality of locations on the main surface thereof, and the through hole is located in a region where the internal conductor film is not formed. The method for manufacturing a ceramic green sheet laminate according to claim 1 or 2 .