JPH0236514A - Manufacture of laminated ceramic electronic component - Google Patents

Abstract

PURPOSE:To conduct a transfer operation maintaining mechanical strength of the material to be transferred by a method wherein after an electrode-buried ceramic raw sheet, which is formed by applying and drying a ceramic slurry covering an electrode part and a ceramic ink part, has been thermo-press welded to another ceramic raw sheet, a supporting member only is exfoliated, and transfer of the electrode part is performed. CONSTITUTION:A ceramic slurry 14 is uniformly coated on an electrode 11 and ceramic ink 13. A hot platen 27, which is heated up by a heater 26, is placed on the side where the electrode-buried ceramic raw sheet 25 of a base film 21a is not formed. On the other hand, a fixed base film 21 and a ceramic raw laminated body 22 are placed on a stand 20. Then, when the electrode- buried ceramic raw sheet 25, which is formed on the surface of the base film 21a, is heated up and press-bonded to the surface of the ceramic raw laminated layer 22 using a hot platen 27, the ceramic raw sheet 25 is transferred to the surface of the ceramic raw laminated body 22, and as a result, a transferred electrode-buried ceramic raw sheet 30, consisting of the transferred electrode 28 and ceramic raw sheet 29, is formed.

Description

[Detailed description of the invention] Industrial applications The present invention relates to a video tape recorder and a liquid crystal television.

This relates to the manufacturing method of multilayer ceramic electronic components such as multilayer ceramic capacitors, which are widely used in electrical products such as OA equipment, and is also widely used in multilayer ceramic electronic components such as multilayer ceramic substrates, multilayer varistors, multilayer piezoelectric elements, etc. It can also be used when manufacturing.

BACKGROUND OF THE INVENTION In recent years, in the field of electronic components, as the density of circuit components has increased, there has been a desire for monolithic ceramic capacitors and the like to be made smaller and have higher performance. Here, explanation will be given using a multilayer ceramic capacitor as an example.

FIG. 7 is a partially sectional view of a multilayer ceramic capacitor. In FIG. 7, 1 is a ceramic dielectric layer, 2 is an internal electrode, and 3 is an external electrode. The internal electrodes 2 are alternately connected to two external electrodes 3.

Recently, electronic components have become increasingly chip-based, and as mentioned above, miniaturization of such multilayer ceramic capacitors is also desired. In this multilayer ceramic capacitor,
A mere reduction in area directly leads to a reduction in electrical capacity. Therefore, it is necessary to simultaneously reduce the size of multilayer ceramic capacitors and increase their capacitance.

In addition to increasing the dielectric constant of the dielectric, methods for increasing the capacitance of multilayer ceramic capacitors include making the dielectric layer thinner,
Multilayer dielectric layers and internal electrodes are being considered.

FIG. 8 is a cross-sectional view of a multi-layer ceramic capacitor when multi-layered. The center of a multilayer ceramic capacitor (
The thickness of the inner electrode 2 (the number of laminated layers is large) compared to the thickness of the peripheral part (
It can be seen that the thickness B of the internal electrode 2 (with a small number of laminated layers) is small. FIG. 9 is a diagram illustrating the difference in thickness between the center and peripheral portions with respect to the number of laminated layers. Here, the thickness of the raw ceramic sheet used is 20 microns, and the thickness of the internal electrodes is 4 microns.From Figure 9, when the number of laminated layers exceeds 10, the difference in thickness between the center and peripheral parts is 20 microns, In other words, it can be seen that the thickness exceeds the thickness of the raw ceramic sheet used.

In the past, several approaches have been taken to address this problem.

First, as in JP-A-56-106244, there is a method in which only electrodes are first printed on a base film, and then a raw ceramic sheet is formed thereon by a casting method. In addition, as in Japanese Patent Publication No. 19975/1975, a method for obtaining an unfired ceramic thin film with electrodes by applying an electrode paint, drying it, continuously applying a dielectric slurry, and peeling it off from the support. There is.

However, when the electrode-embedded ceramic raw sheet made by these methods becomes thinner to about 6 to 20 microns, its mechanical strength is extremely reduced and it can no longer be handled by itself. For this reason, it has been difficult to reduce the thickness to 20 microns or less.

Furthermore, simply embedding electrodes in a green ceramic sheet causes unevenness due to the electrodes to occur on the surface of the green ceramic sheet, making it very difficult to perform high lamination of, for example, 30 or more layers.

This content will be explained below using FIGS. 10 to 12. FIG. 10 is a diagram for explaining an example of a method for manufacturing a raw ceramic sheet with embedded electrodes. 1st o
In the figure, 4 is a base film, 5 is an electrode, 6 is an applicator, 7 is a dielectric slurry, and the applicator 6
is set inside. 8 is an embedded electrode. Further, the arrow indicates the direction in which the base film 4 moves. In FIG. 10, dielectric slurry 7 is applied to the surface of base film 4 on which electrodes 6 have been formed in advance, using applicator 6 in which dielectric slurry 7 is set. Here, the applicator 6 is preferably one that can form a coating film of about 6 to 20 microns. Alternatively, the applicator 6 may be moved while the base film 4 is fixed.

FIG. 11 is a diagram for explaining a cross-sectional view of FIG. 10. In FIG. 11, a state in which dielectric slurry 7 is applied onto electrode 6 by applicator 6 and embedded electrode 8 is formed is explained.

FIGS. 12A, 12B, and 12C are diagrams for explaining how the dielectric slurry 7 coated on the electrode 8 dries. In Figure 12, (A),
In (B) and (c), it can be clearly seen that as the dielectric slurry 7 dries, irregularities caused by the electrode 8 occur.

Problems to be Solved by the Invention In a conventional method for manufacturing a multilayer ceramic capacitor in which electrodes are embedded in a ceramic raw sheet and the electrode-embedded ceramic raw sheet is used, the electrode-embedded ceramic sheet is peeled off onto the laminated support. In addition, especially when multilayering dielectric layers and internal electrodes, it is necessary to remove the level difference caused by internal electrodes between the center and periphery of a multilayer ceramic capacitor. I had two points: I couldn't do it.

In view of the above-mentioned problems, the present invention embeds electrodes in a green ceramic sheet with reduced unevenness, so that even when used in manufacturing a multilayer ceramic capacitor having multiple dielectric layers and internal electrodes, A multilayer ceramic electronic that reduces the level difference caused by internal electrodes between the center and periphery of a multilayer ceramic capacitor, and can handle and transfer even thin ceramic green sheets of about 20 microns or less while maintaining mechanical strength. The present invention provides a method for manufacturing parts.

Means for Solving the Problems In order to solve the above problems, the method for manufacturing a multilayer ceramic electronic component of the present invention provides a method of manufacturing a multilayer ceramic electronic component by applying a slurry of ceramics to a support body on which an electrode part and a ceramic ink part are formed. After applying the ceramic to cover the ink portion, drying the ceramic slurry, making a whole electrode-embedded ceramic green sheet on the support, and then peeling the electrode-embedded ceramic green sheet from the support. After thermocompression bonding onto another raw ceramic sheet or another electrode without any process, only the support is peeled off, and the electrode-embedded raw ceramic sheet is transferred onto the other raw ceramic sheet or other electrode. It has the following configuration.

Function The present invention has the above-described structure, and even when used in manufacturing a multilayered multilayer ceramic capacitor, by filling the irregularities of the electrode with ceramic ink and then applying ceramic slurry, the steps caused by the electrode can be eliminated. This means that it is possible to reduce the Alternatively, a green ceramic sheet with embedded electrodes is thermocompression bonded onto another green ceramic sheet or another electrode without peeling from the support, and then only the support is peeled off and the ceramic green sheet with embedded electrodes is The sheet will be transferred.

EXAMPLE Hereinafter, a method of manufacturing and a method of laminating a multilayer ceramic capacitor according to an example of the present invention will be described with reference to the drawings.

FIG. 1 (A), (B), ((:Th is a diagram for explaining the production of an electrode-embedded ceramic green sheet in one embodiment of the present invention. In FIG. 1, 11 is an electrode , 12 is a base film as a support, 13 is a ceramic ink, and 14 is a ceramic slurry.First, the explanation will be made using FIGS. 1(M) to (C).First, FIG. 1(A) The electrodes 11 are printed on the base film 12 at regular intervals as shown in FIG.

Next, as shown in FIG. 1(B), ceramic ink 13 is printed between the electrodes 11.

As a result, the electrode portion and the ceramic ink portion are formed on the base film 12 with portions that do not overlap with each other. Finally, as shown in Figure 1 (q), a ceramic slurry 14 is uniformly applied on the electrode 11 and the ceramic ink 13. Below, a lamination method using the electrode embedded sheet manufactured in this way will be explained. do.

Wj2 and 3 are diagrams for explaining how the electrode-embedded ceramic raw sheets of the present invention are laminated.

In Figures 2 and 3, 20 is a stand, 21.21ald
Base film, 22, ceramic raw laminate, 23.2
32L is an electrode, 24 is a ceramic green sheet, 26 is a first
This is an electrode-embedded ceramic green sheet produced as shown in the figure, with an electrode 23L and a ceramic green sheet 24.
It is composed of 26 is the heater, 27 is silent, 28
is a transferred electrode, 29 is a transferred electrode-embedded ceramic raw sheet, and 3゛O is a transferred electrode-embedded ceramic raw sheet, which is composed of a transferred electrode 28 and a transferred ceramic raw sheet 29. There is. Further, the arrow indicates the direction of movement of silently 27.

First, explanation will be given using FIG. 2. First, a silent film 27 heated by a heater 26 is placed on the side of the base film 21 & on which the electrode-embedded ceramic green sheet 25 is not formed.
put On the other hand, the base film 21 and the ceramic raw laminate 22 fixed to the stand 20 are placed on the side of the base film 212L on which the electrode embedded ceramic raw sheet 26 is formed.
put

At this time, it is transferred to the surface of the raw ceramic laminate 22.

The electrodes 23 are formed by an appropriate method such as printing.

Here, the electrode 23 does not necessarily need to be formed on the surface of the raw ceramic laminate 22.

Next, from the state shown in FIG. 1, the electrode embedded ceramic raw sheet 25 formed on the surface of the base film 21 &
Heat and press.

Next, explanation will be given using FIG. 3. This FIG. 3 is a diagram after the electrode-embedded ceramic green sheet 25 shown in FIG. 2 has been transferred. That is, as shown in FIG. 3, the electrode embedded ceramic green sheet 26 on the base film 21a is transferred to the surface of the ceramic green laminate 22 by the expression 27, and thereby the transferred electrode 28 and the transferred ceramic green sheet Forming a transferred electrode-embedded ceramic green sheet 30 composed of 29 and
FIGS. 4 and 6 show modifications of the embodiments shown in FIGS. 2 and 3. FIG. In Figures 4 and 5,
The ceramic raw sheet 24a formed on the base film 21b is bonded under heat and pressure to the surface of the ceramic raw laminate 22 on which the electrodes 23 are formed, and after forming the transferred ceramic raw sheet 29&, the electrode-embedded ceramic raw sheet is formed. 25 is shown to be heat-pressed. Here, the second
It is also possible to laminate multiple layers by repeating the steps shown in FIGS. 3 and 3, and the steps shown in FIGS. 4 and 5.

Next, it will be explained in more detail. First, as an electrode ink for forming electrodes, an electrode ink using palladium powder was created. This was prepared by adding butylcarpylene as a solvent to 50.0 parts by weight of palladium powder with a particle size of 0.3 microns, 5.0 parts by weight of ethyl cellulose as a resin, and 0.1 parts by weight of a dispersant to obtain an appropriate viscosity. After adding Thor, thoroughly disperse it using a three-roll mill, and then -
Butylcarpitol was added on a three-mill mill and diluted with dispersion until the viscosity reached 100 poise.

Next, electrode 23! L (and ceramic raw sheet 24)
As the base film 211L for
A roll-shaped polyethylene terephthalate film (hereinafter referred to as PET film) with a film thickness of 75 microns, a center core diameter of 3 inches, and a length of about 100 meters was used.
The electrode ink was printed continuously at regular intervals by a screen printing method using a mesh stainless steel screen. Here, the shape of the electrode is 3.5x1.
o millimeter was used. To dry the electrode ink after printing, a far-infrared belt furnace heated to about 126° C. was connected next to the printing machine, and the solvent in the electrode ink was evaporated to form an electrode 231L.

Next, how to make dielectric slurry and ceramic ink will be explained. First, polyvinyl butyral resin (manufactured by Sekisui Chemical Co., Ltd., BL-2 butyral resin)6.
0 parts by weight, together with 31.0 parts by weight of barium titanate powder with a particle size of 1 micron, in a resin solution consisting of 0.6 parts by weight of diptylphthalate, 25.0 parts by weight of ethyl alcohol, and 36.0 parts by weight of toluene. and stirred well. Next, this was placed in a polyethylene bottle, zirconia beads were added, and the mixture was mixed and dispersed until a suitable dispersion state was obtained. Next, this was subjected to temporary filtration, followed by pressure filtration using a 10 micron membrane filter to obtain a dielectric slurry.

Further, the ceramic ink was prepared in the same manner as the electrode ink.

Next, apply this ceramic ink between the electrodes 110 in a reverse pattern (negative-positive relationship) as shown in Figure 1 (B).
printed and dried.

Next, the dielectric slurry is applied to the electrode and ceramic ink printed base film 2 using an applicator.
Continuously applied on 1&. Next, this was dried to form an electrode-embedded ceramic green sheet 25, and the film thickness of the ceramic green sheet 25 was measured with a micrometer, and the film thickness was 18 microns.

Next, a method for manufacturing a multilayer ceramic capacitor using this electrode-embedded ceramic green sheet 26 will be described. First, a raw ceramic laminate 22 having a thickness of 200 microns and on which no electrodes were formed was fixed together with the base film 21 on a stand 2° in FIG. 2. First, as shown in FIG. 4, the raw ceramic sheet 1-24iL was transferred, and then as many electrode-embedded raw ceramic sheets 25 as the required number of layers were transferred thereon as shown in FIGS. 2 and 3. Here, the transfer was carried out using the Silencer 27 from the side of the base film 211L under the conditions of a temperature of 180'C and a pressure of 16 kilograms per square meter. After transferring the electrode-embedded ceramic green sheet 26, the base film 212L was transferred. I peeled it off and went. At this time, with the electrodes 23° and 23& being shifted by a constant pitch, the next electrode-embedded ceramic green sheet was transferred by heating from the base film 21& using the silent sheet 27.

Thereafter, this process was repeated so that the electrodes were alternately shifted as shown in FIG. 7, so that there were 51 layers of electrodes. and,
Finally, in order to prevent warping during firing and increase mechanical strength, a 200 micron thick ceramic raw sheet without electrodes was transferred.

The thus obtained laminate was 2.4×1. It was cut into chips of e millimeter, and this was made into a laminate according to the method of the present invention.

For comparison, a ceramic green sheet with embedded electrodes was prepared by applying a ceramic slurry on top of the printed electrode ink without printing the ceramic ink, and then producing a green ceramic sheet with embedded electrodes using the conventional method. The laminate was laminated by transfer and cut into chips to obtain a laminate using a conventional method. Note that all conditions such as pressure during lamination and cutting were the same as described above.

Here, the number of samples was n=100. Next, measure the difference in thickness between the center and periphery of the laminate using a thickness meter (surface roughness meter).
Measured using The results are shown in Table 1 below.

Table 1 As described above, by using the method for manufacturing multilayer ceramic electronic components according to the present invention, the difference in thickness between the center and peripheral parts of the finished laminate can be greatly improved compared to the conventional method. I understand what is happening. This is because the electrode-embedded ceramic green sheet of the present invention prevents unevenness caused by the electrodes. Furthermore, in the conventional method, the difference in thickness between the center and peripheral parts of the laminate becomes large, resulting in lamination failure (the electrode-embedded sheet cannot be transferred). Furthermore, when these laminates were fired at 1300 degrees, almost no delamination (separation between layers) was observed in those produced by the method of the present invention compared to those produced by the conventional method.

Note that the ceramic green sheet portion of the electrode-embedded ceramic green sheet used in the present invention has thermal transferability due to the properties of the polyvinyl butyral resin contained therein. However, this thermal transferability is limited by the polyvinyl butyral resin (hereinafter referred to as
The less the amount of PVB resin (called PVB resin), the worse the transferability.
Conversely, the greater the amount of PVB resin contained, the better the transferability. The PVB resin contained in the raw ceramic sheet used here was
Those containing about 20 grams had good transferability.

However, the amount of PVB resin required for transfer varies depending on the particle size of the ceramic powder used as the slurry raw material, the degree of polymerization of the PVB resin, and the temperature during transfer. It is thought that then. If the amount of resin is insufficient, it is necessary to raise the transfer temperature.

Next, Table 2 below shows the results of an experiment regarding the resin liquid contained in the green ceramic sheet and the transferability of the green ceramic sheet using barium titanate powder having the particle size used in the experiment. Here, as mentioned above, the ceramic raw sheet is made of barium titanate powder, diptyl heptatalate as a hardening agent, and PVB resin, and the transfer when the weight percentage of the PVB resin contained therein is changed. I looked into gender. Here, the amount of diptyl phthalate added to the ceramic raw sheet was fixed at 10% by weight of the PVB resin. Regarding the transferability of the green ceramic sheet, an experiment was conducted by transferring a green ceramic sheet with embedded electrodes onto a green ceramic laminate having electrodes formed on its surface as shown in FIG. Further, the transfer was carried out by pressing a cylinder heated to 180'C from the base film side at a transfer pressure of 16 kilograms per square meter. Further, the amount of P''/B resin was expressed in weight % in the raw ceramic sheet.

Next, a multilayer ceramic capacitor was manufactured using the green ceramic sheet shown in Table 2 in the same manner as in the example shown in Table 1. The relationship between the amount of PVB resin contained in the green ceramic sheet and the rate of occurrence of delamination is shown in Table 3 below.

From Table 3, it can be seen that delamination is less likely to occur when the amount of PVB resin is about 10% to 40% by weight. From the above, it can be seen that when the amount of PVB resin is 10% to 40% by weight, especially around 16% by weight of the green ceramic sheet, transferability is good and delamination is less likely to occur.

Here, examples of resins with transferable gold such as PVB resins include acrylic resins and vinyl resins.

There are thermoplastic resins such as cellulose derivative resins.

In addition to thermoplastic resins, even curable resins and polymeric resins can be transferred by adjusting the curing and polymerization conditions appropriately, for example, by making them rubber-like and giving them adhesiveness on the surface. It can be used as a resin for ceramic raw sheets.

Furthermore, in the cases shown in FIGS. 4 and 6, a non-transferable ceramic green sheet containing only about 6 parts by weight of resin per 100 parts by weight of barium titanate is added to the ceramic green sheet 242L. However, by alternately using the electrode-embedded sheets of the present invention having excellent transferability, lamination can be performed.

Furthermore, in laminating the electrode-embedded sheets, the electrode-embedded ceramic green sheets may be transferred using a heated roller as shown in FIG. FIG. 6 is a diagram illustrating the transfer of an electrode-embedded ceramic green sheet using a heated roller. In FIG. 6, reference numeral 31 denotes a heat roller, which is set at a constant temperature by a heater 261. When the electrode-embedded ceramic raw sheet 25 passes between the ceramic raw laminate 22 and the heat roller 31, the electrode-embedded ceramic raw sheet 26 passes through the ceramic raw laminate 22.
2 surface to form a transferred electrode-embedded ceramic green sheet 30. According to this method, the electrode-embedded ceramic green sheet can be transferred continuously.

In the present invention, the transfer may be performed using heat, light, electron beams, microwaves, X-rays, or the like. Furthermore, by changing the type of PVB resin and the type and amount of plasticizer added, transfer at room temperature is also possible. Also, paper,
Transfer is also possible to the surfaces of ceramic substrates, metal plates, etc. It is also possible to use other resins. Furthermore, in the ceramic ink printed between the electrodes, if the dry component ratio of the ceramic ink (such as the ratio of resin to ceramics) is adjusted to the dry component ratio of the ceramic slurry, problems may occur during firing. Hateful. Also, the order of printing the electrodes on the base film and printing the ink on the ceramics is the same regardless of which comes first.
Or you can go at the same time. Furthermore, the printing of ceramic ink between the electrodes does not have to cover all of the laminated layers, but may be printed on only a few layers or a part of them as necessary. Further, there was no particular problem even if the printing of the ink on the ceramics and the printing on the electrodes partially overlapped.

Furthermore, if necessary, a calender treatment (pressing the surface against a metal plate or the like while applying pressure or heat to make the surface smooth) may be performed.

The method of the present invention can be applied not only to the multilayer ceramic capacitor described in the above embodiments but also to other multilayer ceramic electronic components such as multilayer ceramic substrates and multilayer varistors.

Effects of the Invention As described above, the present invention provides the following advantages: After applying a ceramic slurry to a support formed with an electrode part and a ceramic ink part so as to cover the electrode part and the ceramic ink part, The ceramic slurry is dried to form a green ceramic sheet with embedded electrodes on the support, and then the green ceramic sheet with embedded electrodes is heated onto another green ceramic sheet or another electrode without peeling off from the support. After crimping, by peeling off only the support and transferring the electrode-embedded ceramic raw sheet onto the other ceramic raw sheet or another electrode, and by drying the electrode,
Minimizes the negative effects of the solvent contained in the electrode ink,
Furthermore, since the raw ceramic sheet is handled together with the support, it will not be damaged during handling. Furthermore, by printing ceramic ink between the electrodes and then embedding the electrodes with ceramic slurry, we can reduce the occurrence of unevenness on the surface of the electrode-embedded ceramic raw sheet, and improve the yield of multilayer ceramic electronic components such as multilayer ceramic capacitors. can be manufactured.

[Brief explanation of the drawing]

Figures 1 (A), (B), and (C:) are diagrams for explaining the production of an electrode-embedded ceramic raw sheet in one embodiment of the present invention, and Figures 2 and 3 are diagrams for explaining the production of an electrode-embedded ceramic green sheet in an embodiment of the present invention. Figures 4 and 6 are diagrams for explaining how the raw ceramic sheets with embedded electrodes are laminated.
FIG. 6 is a diagram for explaining a state of transfer of an electrode-embedded ceramic raw sheet using a heat roller in another embodiment of the present invention; FIG.
The figure is a cross-sectional view of a part of a multilayer ceramic capacitor, Figure 8 is a cross-sectional view of a conventional multilayer ceramic capacitor when multi-layered, and Figure 9 is a diagram showing the center and peripheral parts with respect to the number of laminated layers. Diagram 10 explaining the difference in thickness of
FIG. 11 is a diagram illustrating the drying of the dielectric slurry shown in FIG. 11. River...7HL12...Base film,
13... Ink for ceramics, 14...
...Ceramics slurry 20...stand, 2
1.21a, 21b...Base film, 2
2...Ceramic raw laminate, 23,232L・
... Electrode, 24 , 242L ... Ceramic raw sheet, 25 ... Electrode embedded ceramic raw sheet, 26 , 262L ... Heater, 27 ...・Silence, 28...Transferred electrode, 29, 292L...Transferred ceramic raw sheet, 30...Transferred electrode-embedded ceramic raw sheet, 31... ...heat roller. Name of agent: Patent attorney Shigetaka Awano and one other person? 0
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Claims (2)

[Claims] (1) After applying a ceramic slurry to cover the electrode part and the ceramic ink part on a support formed by having a portion where the electrode part and the ceramic ink part do not overlap with each other, The ceramic slurry is dried to form a green ceramic sheet with embedded electrodes on the support, and then the green ceramic sheet with embedded electrodes is placed on another green ceramic sheet or another electrode without peeling off from the support. A method for manufacturing a laminated ceramic electronic component, which comprises peeling off only the support after thermocompression bonding, and transferring the electrode-embedded ceramic raw sheet onto the other ceramic raw sheet or another electrode. (2) The method for manufacturing a laminated ceramic electronic component according to claim 1, wherein the ceramic slurry is blended so that the thermoplastic resin content after drying is 10% by weight or more and 40% by weight or less.