JP2001102248A - Method of manufacturing ceramic green sheet laminate - Google Patents

Abstract

PROBLEM TO BE SOLVED: To solve a problem that air taken in between adjacent ceramic green sheets is not be removed, when a plurality of ceramic green sheets are laminated and pressed in a laminating direction to manufacture a ceramic green sheet laminate. SOLUTION: Through-holes 3 are provided in a ceramic green sheet 1. After ceramic green sheets 1 are held by a holding head 4 and are laminated one by one, air between the adjacent ceramic green sheets 1 are removed by applying sucking action from suction holes 8 via the through-holes 3 by the holding head 4, while the plurality of laminated ceramic green sheets are pressed in the laminating direction.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of manufacturing a ceramic green sheet laminate, and more particularly to a method of stacking ceramic green sheets performed in the process of manufacturing a multilayer ceramic electronic component such as a multilayer ceramic capacitor. Things.

[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, 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 stacked as described above, depending on the function of the multilayer ceramic electronic component to be obtained, internal electrodes such as internal electrodes for forming capacitors, inductors, varistors, filters, etc. A conductor film is formed.

[0003]

In order to obtain a multilayer 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 causes 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 adjacent ceramic green sheets when the ceramic green sheets are stacked. Usually, a step of pressing a plurality of stacked ceramic green sheets in the stacking direction. In the above, it is discharged from between adjacent ceramic green sheets. In discharging the air, 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.

[0005] However, in the above-described pressing process, the air may not be discharged smoothly. In particular, in order to realize the miniaturization and high performance of the multilayer ceramic electronic component, for example, in the case of the multilayer ceramic capacitor, in order to realize the miniaturization and high capacity thereof, the ceramic green sheet is made thinner and thinner. As the number of layers increases, it becomes more difficult to discharge such air. Also, 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.

[0006] For more perfect air discharge, a degassing step is provided before the pressing step, or a pressing step is performed while degassing, so that the air between the adjacent ceramic green sheets is removed. Although it is conceivable 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 perfect discharge of the air even if such a means is adopted.

An object of the present invention is to provide a method of manufacturing a ceramic green sheet laminate that can achieve more perfect air discharge as described above.

[0008]

SUMMARY OF THE INVENTION The present invention provides 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 the 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, comprising the step of: , Air is discharged between adjacent ceramic green sheets by suction through the through holes.

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

In the first preferred embodiment described above, more preferably, when stacking the ceramic green sheets, the holding head holds one ceramic green sheet while stacking the ceramic green sheets on the already stacked ceramic green sheets. To be. At this time, the holding head is provided with a suction port communicating with the through hole provided in the ceramic green sheet. In the pressing step, the holding head presses the stacked ceramic green sheets by applying a suction action from the suction port. To be.

[0011] In a second preferred embodiment of the present invention,
A plurality of ceramic green sheets are prepared, and after the plurality of ceramic green sheets are stacked, a through hole is provided so as to penetrate the plurality of stacked ceramic green sheets. Then, by suctioning through the through holes, the 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 films are formed so as to be distributed at a plurality of locations on the main surface of the ceramic green sheet, the above-mentioned through holes do not have such internal conductor films. Preferably, it is located in the area.

[0013]

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 one embodiment of the present invention.

In 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. These internal conductor films 2 are to be used as internal electrodes in a multilayer ceramic capacitor, for example, and are formed by applying a conductive paste by screen printing or the like.

In FIG. 1, only fifteen internal conductor films 2 are shown for ease of illustration, but actually, one internal ceramic green sheet 1 is further provided. Many internal conductor films 2 are often formed.

In such a ceramic green sheet 1, a plurality of through holes 3 are provided. 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 adjacent internal conductor films 2. The through-hole 3 can be formed, for example, by a method such as laser, punch, and drill.

As an example, in this embodiment, the thickness of the ceramic green sheet 1 after firing is 0.5 to 3 mm.
μm, and the thickness of the internal conductor film 2 after firing is 0.6 to
1.2 μm. In addition, ceramic green sheet 1
Is not limited to a circular shape, but when the planar shape of the through hole 3 is circular, the diameter is, for example, 200 to 300 μm.

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

FIG. 2 shows the holding head 4 and the stacking table 5.

The holding head 4 is for holding the ceramic green sheet 1 on its holding surface 6, and the holding surface 6 is provided with a plurality of first and second suction ports 7 and 8, respectively. ing. These suction ports 7 and 8 are provided with a negative pressure for exerting a suction action. The second suction port 8 is positioned 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.

In order to hold the ceramic green sheet 1 on the holding surface 6, the ceramic green sheet 1 itself has an adhesive force or the like, instead of the above-described vacuum suction from the first suction port 7. Good.

The stacking table 5 is for positioning the stacked ceramic green sheets 1, and the mounting surface 9 is provided with a plurality of third and fourth negative pressures similarly to 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 suction 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 a stacking table 5. 1 is shown. 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.

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

Next, from the state shown in FIG. 2 (2), the holding head 4 moves further 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 is sucked through the through holes 3 so as to positively discharge air between the adjacent ceramic green sheets 1. You.
Therefore, undesired air remaining between the adjacent ceramic green sheets 1 is advantageously prevented.

Next, the suction effect 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 is moved to a position (not shown) at which the prepared next ceramic green sheet 1 can be held, and while holding the next ceramic green sheet 1, the holding head 4 shown in FIGS. The process shown in 2) and the subsequent pressing process are repeated.

The ceramic green sheet laminate obtained by stacking and pressing a 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 multilayer ceramic electronic components such as individual multilayer ceramic capacitors.
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 press described above, this may be performed on the stacking table 5, or a rigid press or a hydrostatic press may be applied by placing the ceramic green sheet laminate in another mold. You may do so.

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

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

Further, in the embodiment shown in FIG. 2, the first and second suction ports 7 and 8 are respectively provided at specific positions in the holding head 4. In the case where the suction ports 7 and 8 are made of a porous material or have a net-like structure, any of the suction ports 7 and 8 can be performed by the entire holding surface 6. In this case, the positions of the through holes 3 formed in each of the ceramic green sheets 1 to be used do not always need to be matched.

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. This embodiment is characterized in that after stacking a plurality of ceramic green sheets 1 without through holes, through holes 3 are provided so as to penetrate the plurality of stacked ceramic green sheets 1. . For forming the through-hole 3, for example, a laser may be used in addition to the illustrated drill 12.

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

In this case, the platen 13 shown in FIG. 3 corresponds to the stacking table 5, and the second suction port 8 provided on the holding head 4 and the fourth suction port 11 provided on the stacking table 5. Are the first and third suction ports 7 and 8
In the same manner as described above, it acts to adsorb the ceramic green sheet 1. When the holding head 4 is used as described above, the temporary pressing is performed every time the ceramic green sheets 1 are stacked, separately from the pressing step after the provision of the through holes 3 described above.

Next, the plurality of stacked ceramic green sheets 1 are pressed in the stacking direction while discharging air between adjacent ceramic green sheets 1 by sucking through the above-described through holes 3. The desired 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 a 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, a through hole is provided in a ceramic green sheet, and when a pressing step is performed, air is discharged between adjacent ceramic green sheets by suction through the through hole. 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 the occurrence of structural defects such as lamination and cracks, and therefore, it is possible to enhance the reliability of the multilayer ceramic electronic component constituted by the sintered laminate.

In the present invention, through holes are provided in advance in a plurality of prepared ceramic green sheets, and the ceramic green sheets provided with such through holes are stacked one by one, and then sucked through the through holes. By discharging the air between the adjacent ceramic green sheets in the stacking direction while discharging the air between the adjacent ceramic green sheets as described above, it is possible to discharge the air between the adjacent ceramic green sheets. Is more easily performed.

Further, in the above-described embodiment, a holding head having a suction port communicating with the through hole is used, and the holding head holds one ceramic green sheet on the ceramic green sheets already stacked. In the step of pressing and then pressing in the pressing step, the holding head presses the stacked ceramic green sheets while exerting a suction action from the suction port, so that the transition from the stacking step to the pressing step becomes smooth. At the same time, the suction action from the suction port can be reliably performed so as to discharge the air between the adjacent ceramic green sheets.

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 the plurality of ceramic green sheets, and suction is performed through the through-hole, so that adjacent ceramic green sheets are sucked. While discharging the air between the green sheets,
If a plurality of stacked ceramic green sheets are pressed in the stacking direction, the discharge of air between adjacent ceramic green sheets can be performed at once at a time between a plurality of sets of adjacent ceramic green sheets. The production of the ceramic green sheet laminate can be performed efficiently.

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

[Brief description of the 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 one embodiment of the present invention.

FIG. 2 is a view for explaining a stacking step and a pressing step performed for manufacturing a ceramic green sheet laminate using the ceramic green sheets 1 shown in FIG. 1, and includes a plurality of ceramic green sheets. 1 is a cross-sectional view showing a holding head 4, and a stacking table 5. FIG.

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

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 ceramic green sheet 2 internal conductor film 3 through hole 4 holding head 8 suction port 12 drill

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 5E001 AB03 AD05 AH05 AJ01 AJ02 5E082 AB03 BC32 BC40 EE04 EE35 FG06 FG26 FG52 LL02 MM05 MM13 MM22 MM23

Claims (5)

[Claims] A step of preparing a plurality of ceramic green sheets; a step of stacking the plurality of ceramic green sheets; and a step of pressing the stacked plurality of ceramic green sheets in a stacking direction. A method of manufacturing a ceramic green sheet laminate, further comprising a step of providing a through hole in the ceramic green sheet, wherein the pressing step includes suction through the through hole to remove air between the adjacent ceramic green sheets. A method for producing a ceramic green sheet laminate, comprising: 2. A step of preparing a plurality of ceramic green sheets provided with through holes;
Stacking the sheets one by one, and by suctioning through the through holes, while discharging air between the adjacent ceramic green sheets,
Pressing the ceramic green sheets stacked in the stacking step in the stacking direction. 3. The stacking step includes a step of stacking the ceramic green sheets already stacked while holding one ceramic green sheet by a holding head, wherein the holding head is provided in the through hole. The ceramic green according to claim 1, further comprising a suction port communicating with the ceramic green sheet, wherein the pressing includes pressing the stacked ceramic green sheets by the holding head while exerting a suction action from the suction port. A method for manufacturing a sheet laminate. 4. 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 the stacked ceramic green sheets. By sucking through the through holes, while discharging air between the adjacent ceramic green sheets,
Pressing the plurality of stacked ceramic green sheets in the stacking direction in the stacking direction. 5. The ceramic green sheet has an internal conductor film formed so as to be distributed at a plurality of locations on a main surface of the ceramic green sheet, and the through hole is located in a region where the internal conductor film is not formed. The method for producing a ceramic green sheet laminate according to any one of claims 1 to 4.