JP2003039418A - Method for manufacturing ceramic electronic component - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for manufacturing a ceramic electronic component having a high yield by suppressing a structural defect caused by a cutting step. SOLUTION: The method for manufacturing the ceramic electronic component comprises the steps of fixing a laminated block 11 obtained by alternatively laminating a ceramic sheet and a conductor layer, onto a pedestal 10, push cutting the block 22 by a cutter 12 made of a metal, then moving the cutter 12 in parallel, cutting plural times the block 11 while confirming a cutting position, thereby obtaining a laminate, cutting at this time while removing the block component adhered to the cutter 12, then baking the laminate and forming an external electrode.

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 electronic component such as a monolithic ceramic capacitor.

[0002]

2. Description of the Related Art A conventional method for manufacturing a ceramic electronic component will be described by taking a multilayer ceramic capacitor as an example.

FIG. 3 is a perspective view of a conventional laminated body.

First, a ceramic sheet to be the dielectric layer 1 is produced by using ceramic powder such as barium titanate, a binder such as acrylic resin or polyvinyl butyral resin, and a plastic material such as dibutyl phthalate.

Next, Ni is formed on the surface of the ceramic sheet.
A plurality of conductor layers 2 made of metal powder such as and ethyl cellulose, acrylic resin, polyvinyl butyral resin, etc. are formed.

Next, a plurality of the ceramic sheets are stacked so that the conductor layers 2 face each other with the ceramic sheet sandwiched therebetween, to produce a laminated block.

After that, the laminate block is cut by using a metal blade in the vertical direction a plurality of times on the upper surface of the block of the laminate to separate the laminate into a desired shape.

Next, the laminated body is fired to obtain a sintered body, and external electrodes are formed on both end surfaces of the sintered body where the conductor layer 2 is exposed.

[0009]

SUMMARY OF THE INVENTION In this method,
When cutting the laminate block, the laminate block components (ceramic powder, resin, metal powder) adhere to the blade. When cutting is performed a plurality of times while the laminated body block component is attached to the blade, the friction between the blade and the laminated body block increases due to the adhered matter accumulated on the side surface of the blade. As a result, as shown in FIG. 3, there is a problem that structural defects 3 occur at the cut end of the laminate.

In particular, the ceramic sheet and the conductor layer 2
If an attempt is made to increase the number of stacked layers and increase the capacity, the decrease in yield due to the structural defect of the stacked body caused by the cutting method becomes a serious problem.

Therefore, it is an object of the present invention to provide a method for manufacturing a ceramic electronic component having a high yield by suppressing the occurrence of structural defects caused by the cutting process.

[0012]

To achieve the above object, the present invention provides the following method.

The invention according to claim 1 of the present invention is
After removing the laminated block component attached to the blade by cutting the laminated block, it is to cut the laminated block again, reduce the friction between the blade and the laminated block, damage to the cut end of the laminated body, That is, it is possible to suppress the occurrence of structural defects and improve the yield.

The invention according to claim 2 of the present invention is
The removal of the laminate block component adhering to the blade is carried out by bringing it into contact with a substance that dissolves the organic matter in the laminate block, and the deposit can be easily removed.

The invention according to claim 3 of the present invention is
The blade deposit is removed with a substance that dissolves organic matter in the laminate block, and after removing the liquid component on the surface of the blade, the laminate block is cut again, and when the laminate block is cut again, It is possible to prevent the laminate block from being dissolved by the liquid on the surface of the blade.

The invention according to claim 4 of the present invention is
The removal of the laminated block component adhering to the blade is carried out by passing it through the elastic porous body impregnated with the liquid that dissolves the organic matter in the laminated block, and the adhering matter can be removed without stopping the movement of the blade. Since it can be removed, productivity can be secured.

The invention according to claim 5 of the present invention is
Since the blade surface has irregularities of 10 μm or less on average, the friction between the blade and the laminate block is reduced, adhesion of the laminate block component to the blade is prevented, and damage to the cut end of the laminate, that is, structure Occurrence of defects can be suppressed.

The invention according to claim 6 of the present invention is
The blade surface is coated with a resin containing an abrasive,
While suppressing blade wear, it is possible to reduce the friction between the blade and the laminate block, damage to the cut end of the laminate,
That is, the occurrence of structural defects can be suppressed.

[0019]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, with reference to the drawings, a first embodiment to a sixth embodiment of the present invention will be described with reference to the drawings, taking a laminated ceramic capacitor as an example.

FIG. 1 is a perspective view showing a cutting process of a monolithic ceramic capacitor according to an embodiment, in which a laminated body block 11 is fixed on a pedestal 10 having a horizontal upper surface and a blade 1 is provided.
The laminate block 11 is cut at 2, and the laminate block component attached to the blade 12 is removed by the porous elastic body 13 impregnated with the organic solvent. The arrow in the figure indicates the traveling direction of the blade 12.

FIG. 2 is a partially cutaway perspective view of the monolithic ceramic capacitor according to the embodiment.
The external electrodes 23 are formed on both end surfaces of the conductor layer 22 of the laminated body in which 1 and the conductor layer 22 are alternately laminated.

First, a ceramic sheet to be the dielectric layer 21 is formed by using ceramic powder containing barium titanate as a main component, a binder such as acrylic resin or polyvinyl butyral resin, a plastic material such as dibutyl phthalate, and a solvent such as butyl acetate. Manufactured by the doctor blade method. The thickness of the ceramic sheet is about 8 to 10 μm.

Next, this ceramic sheet was cut into a length of 5 cm and a width of 5 cm, and a metal paste containing Ni powder as a main component and containing ethyl cellulose, acrylic resin, polyvinyl butyral resin, butyl acetate, etc. was screen-printed on the surface to obtain a conductor. A plurality of layers 22 are formed. The conductor layer 22 has a rectangular parallelepiped shape having a length of 2 mm, a width of 3 mm, and a thickness of 2 to 2.5 μm, and is arranged on the ceramic sheet in about 100 rows and columns.

Next, the ceramic sheet is placed 150 so that the conductor layers 22 face each other with the ceramic sheet sandwiched therebetween.
While stacking the sheets and heating to a temperature at which the organic substances contained in the ceramic sheet and the conductor layer 22 start to soften, 5
Pressure is applied at MPa to 20 MPa to integrate the ceramic sheets and the ceramic sheet with the conductor layer 22,
The laminated body block 11 is produced.

The laminated body block 11 can be cut to obtain about 100 laminated bodies.

Thereafter, the laminated block 11 is fixed to the base 10 as shown in FIG. 1, and the base 10 is fixed with a metal blade 12.
With respect to the vertical direction, that is, the laminate block 11 is completely pressed.

Next, the blade 12 is moved in parallel, and the laminate block 11 is cut a plurality of times while confirming the cutting position.

Next, the laminated body block 11 is rotated 90 degrees with respect to the blade 12 and similarly cut a plurality of times to make a vertical 2.
A laminated body having a size of 5 mm and a width of 3.5 mm is produced.

The cutting step will be described in detail.

The blade 12 is made of an ultra-hard metal or ceramic that is sufficiently hard for the laminate block 11 having a maximum thickness of about 150 μm, and is longer than the width of the laminate block 11. The angle formed by the cutting edge is 10 to 20 degrees,
When cutting the laminated body block 11, the laminated body is prevented from being deformed due to the thickness of the blade edge.

Further, as the cutting is repeated a plurality of times, a laminated body block component such as ceramic powder or resin adheres and deposits on the blade 12. This attached matter increases the friction between the blade 12 and the laminated body block 11, damages the cut end of the laminated body block 11, and induces the structural defect 3 as shown in FIG.

Therefore, as shown in FIG. 1, a porous elastic body 13 impregnated with an organic solvent such as butyl acetate or isopropyl alcohol that dissolves organic substances contained in the laminated body block 11 is arranged near the laminated body block 11. Then, after the blade 12 cuts the laminated body block 11, the blade is passed through the inside of the porous elastic body 13. Then, the laminate block component attached to the surface of the blade 12 during the cutting is removed by the porous elastic body 13
The blade 1 can be cut by performing a cleaning process in which it is dissolved with the organic solvent contained in and is wiped off with the porous elastic body 13.
It is possible to suppress the occurrence of structural defects due to friction between 2 and the laminated body block 11.

However, when the laminate block 11 is cut while a large amount of the organic solvent is attached to the blade 12, the laminate block component is attached on the contrary. Therefore, it is desirable to use an organic solvent having a relatively high volatility, or to remove the deposit on the blade 12 and then remove the liquid on the surface of the blade 12.

The friction of the blade 12 with respect to the laminated block 11 is also greatly affected by the surface roughness of the blade 12.
When the surface roughness is larger than 10 μm, friction between the blade 12 and the laminated body block 11 is large, which may damage the cut end of the laminated body. Further, when the surface of the blade 12 is a mirror surface, the contact area with the laminated body block 11 becomes large, and the friction also becomes large. Therefore, it is desirable that the surface of the blade 12 has unevenness of 10 μm or less on average.

Further, the blade 12 is worn by such a cutting process. If the wear is great, the laminate block 11 cannot be cut appropriately, so that the blade 12 needs to be replaced many times, resulting in poor productivity. Therefore, it is desirable to use a blade 12 whose surface is coated with a resin containing a hard powder such as diamond powder. Also in this case, it is preferable to use hard powder having a particle size of 10 μm or less so that the surface of the blade 12 has irregularities of 10 μm or less on average. Further, as the resin, it is desirable to use a silicon-based or Teflon (registered trademark) -based resin that is unlikely to adhere to the organic matter contained in the laminate block 11.

Taking the above into consideration, the laminate block 11 is cut into individual laminates and then separated.

Subsequently, after removing the organic substances of the individual laminated bodies in nitrogen gas, 1300 in a nitrogen-hydrogen mixed gas atmosphere in which nickel serving as the conductor layer 22 is not excessively oxidized.
A heat treatment is performed up to ° C and firing is performed to obtain a sintered body.

Next, the sintered body is chamfered to completely expose the conductor layer 22 on both end surfaces of the sintered body. Then, after applying an electrode paste containing copper as a main component to both end faces and side faces of the sintered body, baking is performed in a nitrogen atmosphere at 800 ° C. to form an external electrode 23, and nickel and solder are plated on this. Then, a monolithic ceramic capacitor as shown in FIG. 2 is manufactured.

To more clearly show the effect of the present invention, the blade 12 is used until the laminate block 11 is cut into individual laminates.
No removal of the laminated block component adhered to (Sample 1), and each time the laminated block 11 was cut once, the blade 12 was passed through the porous elastic body 13 impregnated with butyl acetate, Each of the laminates 10 (Samples 2 to 4) from which the laminate block component attached to the surface was removed was used.
The number of occurrences of laminated bodies in which structural defects occurred at 0 cuts is shown in (Table 1).

[0040]

[Table 1]

As can be seen from this (Table 1), in the step of cutting the laminated body block 11, by removing the laminated body block component adhering to the blade 12, the occurrence of structural defects is suppressed and the yield is improved. Can be made.

Further, the unevenness of the surface of the blade 12 is set to 10 μm or less (Sample 3), or the surface of the blade 12 is coated with a resin in which diamond powder is dispersed (Sample 4) to further generate structural defects. Can be suppressed.

In the above-described embodiment, the surface of the blade 12 is cleaned every time the laminate block 11 is cut, but the laminate block component adhering to the blade 12 is below a certain level. In this case, it is not necessary to wash each time. The cutting speed becomes slower as the number of washings increases. Therefore, it is desirable to determine the number of times of cleaning in accordance with the degree to which the laminate block component adheres to the blade 12.

Further, the porous elastic body 13 is preferably one having a hardness that does not damage the blade 12 and capable of wiping off a laminate block component dissolved in an organic solvent such as sponge or fibrous material. .

Further, the liquid used for cleaning the blade 12 may be any liquid as long as it dissolves the organic substances contained in the laminate block 11, but the ceramic sheet or the metal paste is used so as not to adversely affect the laminate block 11. The solvent contained therein is preferred.

In the present embodiment, the solvent-impregnated porous elastic body 13 is arranged in the vicinity of the laminate block 11, and the blade 12 is passed through the inside of the laminate to adhere the laminate 12 to the blade 12. The block component was removed. In place of this method, the blade 12 is moved from one end to the other end while sandwiching the solvent-impregnated porous elastic body 13 from both sides to wipe off the deposits on the blade 12. You can use it.

Further, although the monolithic ceramic capacitor has been described in the above-mentioned one embodiment, the same applies to a ceramic sheet such as a laminated varistor, a laminated thermistor, a laminated coil, a ceramic multilayer substrate and a ceramic electronic component formed by laminating ceramic sheets. The effect of is obtained.

[0048]

As described above, according to the present invention, when at least the laminate block component adheres to the blade in the step of cutting the laminate block, the adhered matter is removed and then the blade is laminated by cutting. The friction with the body block can be reduced, the occurrence of structural defects in the laminate can be suppressed, and the yield can be improved.

[Brief description of drawings]

FIG. 1 is a perspective view for explaining a cutting process of a laminate block according to an embodiment of the present invention.

FIG. 2 is a partially cutaway perspective view of a monolithic ceramic capacitor according to an embodiment of the present invention.

FIG. 3 is a perspective view of a conventional laminated body.

[Explanation of symbols]

10 pedestals 11 Laminated block 12 blades 13 Porous elastic body 21 Dielectric layer 22 Conductor layer 23 External electrode

   ─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor Yoshiya Sakaguchi             1006 Kadoma, Kadoma-shi, Osaka Matsushita Electric             Sangyo Co., Ltd. (72) Inventor Katsuyuki Miura             1006 Kadoma, Kadoma-shi, Osaka Matsushita Electric             Sangyo Co., Ltd. F-term (reference) 4G055 AA08 AC09 BB12                 5E082 AA01 AB03 EE04 EE35 FF05

Claims (6)

[Claims] 1. A first step of preparing a laminate block in which a ceramic sheet containing an organic substance and a conductor layer are laminated, a second step of fixing the laminate block to a pedestal, and the laminate block. A laminate block attached to the blade in the third step, and a third step of cutting the laminate with a blade a plurality of times, and then a fourth step of separating the laminate block into individual laminates and firing. A method for manufacturing a ceramic electronic component for removing components. 2. The method for producing a ceramic electronic component according to claim 1, wherein the removal of the laminated body block component attached to the blade is carried out by bringing it into contact with a substance that dissolves an organic substance in the laminated body block. 3. The method of manufacturing a ceramic electronic component according to claim 2, wherein after removing the laminated body block component attached to the blade, the liquid component on the surface of the blade is removed. 4. The ceramic electronic component according to claim 1, wherein the component of the laminate block adhered to the blade is removed by passing it through a porous elastic body impregnated with a liquid that dissolves an organic substance in the laminate block. Manufacturing method. 5. The method of manufacturing a ceramic electronic component according to claim 1, wherein the surface of the blade has irregularities with an average of 10 μm or less. 6. The method for manufacturing a ceramic electronic component according to claim 1, wherein the surface of the blade is coated with a resin containing an abrasive.