JPH0236509A - Manufacture of laminated ceramic electronic component - Google Patents

Abstract

PURPOSE:To reduce the stepping generated by an internal electrode by a method wherein the electrode-buried ceramic raw sheet, which is formed by flattening the uneaveness generated on a electrode section by printing in ceramic ink, is thermo-press welded or transferred to the other ceramic raw sheet or the other electrode without having the above-mentioned ceramic raw sheet exfoliated from a supporting member. CONSTITUTION:First, electrodes 11 and 11 are printed on a base film 12. Then, the slurry 13 of a first ceramic is coated on the electrodes 11 and 11 and it is dried up. Subsequently, ceramic ink 14 is printed on the recessed parts generated between the electrodes 11 and 11, and said recessed parts generated between the electrodes 11 and 11 are filled up. An electrode-buried ceramic raw sheet 25 is manufactured through the above-mentioned procedures. When the obtained ceramic raw sheet 25 is heated up and fixed by pressure to the surface of a base film 21a, said ceramic raw sheet is transferred to the surface of a ceramic raw laminated body 22. As a result, an electrode-buried ceramic raw sheet 30, consisting of a transferred electrode 28 and a 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 article relates to the manufacturing method of multilayer ceramic electronic components such as 5-layer ceramic capacitors, which are widely used in electrical products such as 0-μm equipment, and also includes a wide range of other products such as multilayer ceramic substrates, multilayer varistors, multilayer piezoelectric elements, etc. It can also be used in manufacturing laminated ceramic electronic components.

Two Conventional Technologies In recent years, in the field of electronic components, as the density of single circuit components has increased, there has been a desire for further miniaturization and higher performance of multilayer ceramic capacitors and the like. Here, a multilayer ceramic capacitor will be explained as an example.

FIG. 7 is a cross-sectional view of a part of the multilayer ceramic capacitor. In FIG. 7, 1 is a ceramic dielectric layer, 2 is an internal metal, and 3 is an external electrode. The internal electrodes 2 are alternately connected to and read by two external electrodes 3.

Recently, there has been a remarkable trend toward chipping of electronic components, and miniaturization of such multilayer ceramic capacitors as described above is also desired. In this multilayer ceramic capacitor, a mere reduction in area directly leads to a reduction in electrical capacity. For this reason, it is necessary to make multilayer ceramic capacitors smaller and at the same time 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,
Multilayering of sleep inducer layers and internal electrodes is being considered.

FIG. 8 is a cross-sectional view of a multilayer ceramic capacitor when it is multi-layered. As shown in FIG. It can be seen that the thickness B of the peripheral portion (the product 1·i of the internal electrodes 2 is small) is small.

FIG. 9 is a diagram illustrating the difference in thickness between the center portion and the peripheral portion with respect to the number of laminated layers. The thickness of the raw ceramic sheet used here was 20 microns, and the thickness of the internal electrodes was 4 microns. From FIG. 9, it can be seen that when the number of laminated layers exceeds 10, the difference in thickness between the center and the periphery exceeds 20 microns, that is, the thickness of the raw ceramic sheet used.

Up until now, several approaches have been taken to address the problem.

First, as in Japanese Patent Application Laid-open No. 106244/1983, 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. 40-19975, it is possible to create an unfired ceramic with electrodes by applying dielectric paint, drying it, continuously applying dielectric slurry, and peeling it off from the support. There are ways to obtain thin films.

However, when the electrode-embedded ceramic green sheet produced 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, which is extremely difficult to do when, for example, 30 or more layers are formed.

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. 10th
In the figure, 4 is a base film, 5 is an electrode, 6 is an applicator, and 7 is a single dielectric slurry, which is set in the applicator 6. 8 is an embedded electrode. Further, the arrow indicates the direction in which the base film 4 moves.

In FIG. 10, the dielectric slurry 7 is applied to the surface of the base film 4 on which the electrodes 5 have been formed in advance by an applicator 6 ic set with the dielectric slurry 7. Here, the applicator 6 is preferably one that can form a coating pattern with a difference of about 5 to 20 microns. The applicator 6 may be moved while the base film 4 is still fixed.

FIG. 11 is a diagram for explaining a cross-sectional view of FIG. 10. In FIG. 11, a state in which a dielectric slurry 7 is applied by an applicator 6 onto the electrode 5 and an embedded electrode 8 is formed will be explained.

Figures 12 (B) and (C) are diagrams for explaining how the dielectric slurry 7 applied on the electrode 8 dries. ) (
It can be clearly seen that as the dielectric slurry layer C) dries, unevenness occurs due to the electrode 8.

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 green sheet and the electrode-embedded ceramic green sheet is used, the electrode-embedded ceramic sheet is peeled off onto a support. However, there was a limit to how thin the layer could be.

In addition, especially when multilayering dielectric layers and internal electrodes, there is a point where it is impossible to eliminate the level difference caused by the internal electrodes between the center and the periphery of the multilayer ceramic capacitor. Was.

The present invention solves the above-mentioned problems, and by embedding electrodes in a green ceramic sheet with reduced unevenness, the present invention can be used to manufacture multilayer ceramic capacitors with multilayered dielectric layers and internal electrodes. It reduces the level difference that occurs in the internal electrodes between the center and periphery of a multilayer ceramic capacitor, and can handle and transfer even thin ceramic raw sheets of about 20 microns or less while maintaining the strength of a thief. A method for manufacturing a multilayer ceramic electronic component is provided.

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 includes coating a ceramic slurry on a support on which an electrode portion is formed, and then applying the ceramic slurry to a support body on which an electrode portion is formed. Let it dry.

The unevenness caused by the electrode portion generated at this time is filled by printing ceramic ink, an electrode-embedded ceramic green sheet is made, and the first step is to remove the electrode-top-embedded ceramic green sheet from the support, without peeling it off. After thermocompression bonding onto another ceramic raw sheet or another electrode, only the support is peeled off, and the electrode-embedded ceramic raw sheet is transferred onto the other ceramic raw sheet or other electrode. It's something to prepare for.

Operation The present invention has the structure 5jEK described above, and when manufacturing a multi-layered multilayer ceramic capacitor, it is possible to prevent unevenness of the electrodes that occurs after applying ceramic slurry to the electrodes by applying ceramics to the recesses. By printing and filling the ink, it is possible to reduce the level difference that occurs in the electrodes.In addition, the ceramic raw sheet with embedded electrodes can be attached to other ceramic raw sheets without peeling from the support. Alternatively, after thermocompression bonding onto another electrode, only the support is peeled off, and the electric wire-embedded ceramic green sheet is 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.

FIGS. 1(M) to 1(D) are diagrams for explaining the production of a raw ceramic sheet with embedded beads in one practical example of the present invention. Figure 1 (in C, 11: i electrode, 12: discharged base film, 13: first ceramic slurry, 14: ceramic ink, 15d: second
It is a slurry of ceramics. First, Figure 1 (mu)
This will be explained using (C). First, as shown in FIG. Next, as shown in FIG. 1(B), a first ceramic slurry 13 is applied onto the electrode 11 and dried. Next, the first
As shown in Figure (C), ceramic ink 14 is printed on the concave portions formed between the electrodes 11 to fill the concave portions formed between the electrodes 11. If necessary, apply a second ceramic slurry 16 as shown in FIG. 1(D) to further improve the area.
It is possible to flatten the unevenness caused by 1.

A lamination method using the electrode-embedded ceramic raw sheet manufactured in this way will be explained below.

FIGS. 2 and 3 are diagrams for explaining electrons laminated with electrode-embedded ceramic raw sheets of the present invention. In Figures 2 and 3, 20 is a stand.

21 and 211 are base films, 22 are ceramic green laminates, 23 and 231 are electrodes, 24 (d are ceramic green sheets, and 25d are electrode-embedded ceramic green sheets manufactured as shown in FIG. 1).

It is composed of electricity@23& and ceramic green sheet 24 for discussion. 26 is a heater, 27 is a heating plate, 28 is a transferred electrode, 29 is a ceramic green sheet with embedded electrodes,
Reference numeral 30 denotes a transferred ceramic green sheet with embedded electrodes, which is composed of transferred electrodes and a transferred ceramic green sheet 29). Also, arrow'ri hot plate 27
Show the direction.

First, explanation will be given using FIG. 2. First, the heater 26 is added to the side of the base film 21 & on which the electric beads embedded ceramic green sheet 25 is not formed, and the swallow board 2
give up. On the other hand, the base film 21 and the ceramic raw laminate 2 are fixed on the base film 21a on the side where the electrode-embedded ceramic raw sheet 25 is formed.
Place 2. At this time, electrodes 23 are formed on the surface of the raw ceramic laminate 22 by an appropriate method such as transfer or printing. Here, the electric metal 23 does not necessarily need to be formed on the surface of the raw ceramic laminate 22. Next, this second
From the state shown in the figure, the electrode-embedded ceramic green sheet 25 formed on the surface of the ceramic green laminate 22 and the surface of the base film 211L is heated and bonded by heat and pressure using a heating layer 27.

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 raw ceramic sheet 26 embedded on the base film 211L is transferred to the surface of the raw ceramic laminate 22 by the hot platen 27, and the transferred electrode 28 and the transferred raw ceramic sheet 26 are A transferred electrode-embedded ceramic green sheet 3o composed of the ceramic green sheet 29 is formed.

Further, FIGS. 4 and 6 show modifications of the above-mentioned embodiment. 4 and 5, a ceramic raw sheet 24 is formed on the base film 21b on the surface of the ceramic raw laminate 22 on which the electrode 23 is formed.
A is heat-pressed and transferred to the ceramic green sheet) 2.
91L is formed, and then the electrode-embedded ceramic green sheet 25 is bonded under heat and pressure. Here, it is also possible to laminate multiple layers by repeating the steps shown in FIGS. 2 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 made using butyl as a solvent to obtain an appropriate viscosity for 50.0 parts by weight of palladium powder with a grain size of 0.3 microns, 6.0 parts by weight of ethyl cellulose as a resin, and 0.11 parts by weight of a dispersant. After adding carpitol, it was thoroughly dispersed using a three-roll mill, and then butyl carpitol was added again on the three-roll mill, and the mixture was diluted while being dispersed until the viscosity reached 100 poise.

Next, as a base film 212L for 7 [123a (and ceramic raw sheet 24), a film width of 200 mm, a film thickness of 76 microns, and a center core diameter of 3
Using a roll-shaped polyethylene terephthalate film (hereinafter referred to as -PET film) with a length of about 100 meters and a length of about 100 meters, the above-mentioned electrode ink was printed on it by a screen printing method using an emulsion of 11Q micron and a 40o mesonue stainless steel screen. I performed 11 stamps in succession at regular intervals. Here, the shape of the electrode is 3.15
A size of 1.0 mm 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 to evaporate the solvent in the electrode ink, and this was used as the electrode 23&.

Next, how to make dielectric book slurry and ceramic ink will be explained. First, polyvinyl butyral resin (BL-2 butyral resin manufactured by Sekisui Chemical Co., Ltd.) 6.
0 parts by weight, 0.6 parts by weight of diptyl phthalate, and 25.0 parts by weight of ethyl alcohol.

Toluene 36. OM quantity part Yoshinaru pottery, finger melting: In the middle of the night, barium titanate powder with a particle size of 1 micron 31. o parts by weight and stirred thoroughly. 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, and then subjected to pressure filtering using a single micron membrane filter to obtain a dielectric slurry. Further, the ceramic ink was manufactured in the same manner as the electrode ink.

Next, dielectric nullary is applied to the electrode and the base film 2 marked with ceramic ink using an applicator.
It was applied in series on 1a. Next, this was dried to form an electrode-embedded ceramic green sheet 25, and the film thickness was measured with a micrometer, and the film thickness of the ceramic green sheet 26 was 41 microns.

Next, apply ceramic ink to Kf as shown in Figure 1 (C).
A mark 1611 was made between the i-poles 11 with a reverse electrode pattern (negative-positive relationship), and the electrode-embedded ceramic raw sheet 25 was flattened by drying.

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 with no electrodes having a thickness of 200 microns was fixed together with the base film 21 on the stand 2o shown in FIG. 2. First, as shown in FIG. 4, a raw ceramic sheet 242L was transferred, and on top of this, the required number of laminated ceramic raw sheets 25 with electromechanical inlays were transferred as shown in FIGS. 2 and 3. Here, the transfer is performed at a temperature of 1
The heating plate 27 was used from the side of the base film 211L under conditions of 80° C. and a pressure of 15 kilograms per square centimeter to transfer the polarized embedded ceramic raw sheet 25, and then the base film 21 was peeled off. . At this time, with the electrodes (23, 23a) shifted by a certain pitch, the primary electrode-embedded ceramic raw sheet is placed on the hot platen 2.
The transfer was performed by heating from the base film 211 side using No. 7.

Thereafter, this process was repeated so that the electrodes were alternately shifted as shown in FIG. 7, so that there were 61 layers of electrodes. and,
Finally, in order to prevent warpage during firing and increase mechanical strength, a 200 micron thick ceramic raw sheet without electrodes was transferred.

The thus obtained laminate was cut into chips of 2.4 x 1.6 millimeters, and this was used as a laminate according to the method of the present invention.

For comparison, we will use conventional two-core ceramic raw sheets with electrode ink printed on which ceramic slurry was applied, and electrode-embedded ceramic raw sheets with unevenness remaining without ceramic ink printing. A sheet was produced, laminated by transfer in the same manner, and cut into chips to form 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 width meter).
Measured using The results are shown in Table 1 below.

[Table 1] As shown above, if the single-strip manufacturing method for multilayer ceramic electronic components according to the present invention is used, the difference in thickness between the center and peripheral parts of the finished laminate will be smaller than that of the conventional method. I can see that it has been greatly improved. This is because the generation of irregularities caused by the bottom and base is prevented in the ceramic raw sheet with embedded ink of the present invention. In addition, in the conventional method, there was a large difference in thickness between the center and the periphery of the laminate, and lamination failure (the electrode embedded sheet could not be transferred) occurred. Furthermore, when these laminates were fired at 1300 degrees Celsius, almost no delamination was observed in those produced by the method of the present invention compared to those produced by the conventional method.

Here, according to the present invention, it is preferable that the thermoplastic resin content of the first or second ceramic slurry in the first factor after drying is 10% by weight or more and 40% by weight or less. Obtained. This will be briefly explained below.

The ceramic green sheet portion of the polarized embedded ceramic green sheet used in the present invention has thermal transferability due to the polyvinyl butyral A-containing quasi contained therein. Also,
The less polyvinyl phthalate A fingers (hereinafter referred to as PVBJ fat) contained in the raw ceramic sheet, the worse the transferability due to heat; The larger the amount, the better the transferability.

Regarding the PVB resin contained in the raw ceramic sheet used here, transfer and raw materials were good when the amount was about 20 grams per 100 grams of ceramic powder. but,
Here, the PVB resin required for transfer depends on the particle size of the ceramic powder used as the slurry raw material, the degree of polymerization of the PVB resin (class 1, etc.), or the temperature at the time of transfer. The required amount of resin is thought to vary, and if the amount of resin is insufficient, it is necessary to increase the transfer temperature.

Next, Table 2 below shows the results of a practical test regarding the amount of resin contained in the raw ceramic sheet and the transferability of the raw ceramic sheet for the titanate powder having the particle size used in the test. Show here.

As mentioned above, the ceramic raw sheet is made of titanate/(lium powder), dibutyl phthalate as a plasticizer, and PVB resin, and the transferability when changing the weight percentage of the PVBI resin contained therein is I looked into it. Here,
The amount of dredged dibutyl phthalate added into the ceramic green sheet was fixed with 10 weight copies of PvB resin. Furthermore, the contrast ratio of the green ceramic sheet was actually tested by transferring the green ceramic sheet with embedded electrodes onto a green ceramic laminate with electrodes formed on the surface as shown in FIG. Transfer 1 was performed by pressing a hot plate heated to 180° C. from the base film side at a transfer pressure of 15 kilograms per square meter. Also, PVB
The amount of resin was expressed as the amount of balls in the raw ceramic sheet (%).

[Table 2] Next, using the green ceramic sheet shown in Table 2 above,
A multilayer ceramic capacitor was manufactured in the same manner as in the example shown in the table. Table 3 below shows the relationship between the PVB resin-1 contained in the raw ceramic sheet and the incidence of delamination at this time.

[Table 3] From Table 3, it can be seen that delamination is less likely to occur when the amount of PVB resin is between 10 and 40 weight. From the above, it can be seen that when the amount of PVB resin is in the range of 10 to 40 weight of the raw ceramic sheet, especially around 16 weight, the transferability is good and delamination is less likely to occur.

Here, other resins having transferability such as P'B resin include thermoplastic resins such as acrylic sugar beet, vinyl resin, cellulose derivative resin, and side resin.

In addition to thermoplastic resins, even if hardening resins and polymerization are used, the conditions for facilitating and polymerization should be adjusted appropriately.
By making it rubber-like, it can be transferred by giving the surface adhesiveness, and 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 5 parts by weight of resin per 100 parts by weight of titanium wave barium is added to the ceramic green sheet 241L. However, by alternately using the electrically embedding sheets of the present invention having excellent transferability, lamination can be performed.

Furthermore, in the lamination of electric-pressing sheets.

As shown in FIG. 6, a hot roller may be used to transfer the ceramic green sheet embedded with the electric and cassettes. FIG. 6 is a diagram for explaining the transfer of a green ceramic sheet with embedded beads using a heated roller. In FIG. 6, 31 is a heat roller whose temperature is set to a constant temperature by a heater 262L. And electrode-embedded ceramic raw sheet 25
When passing between the green ceramic laminate 22 and the heat roller 31, the electrode-embedded green ceramic sheet 26 is transferred to the surface of the ceramic green laminate 22, becoming a transferred electrode-embedded ceramic green sheet 3o. 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. Another paper,
Transfer is also possible to the surfaces of ceramic substrates, metal plates, etc. Also.

It is also possible to use other resins. Furthermore, in ceramic ink that prints on the recesses created between electrodes,
If you know the component ratio of the ceramic ink after drying (such as the ratio of resin to ceramics) and the component ratio of the ceramic slurry after drying, problems will be less likely to occur during firing. Furthermore, it is not necessary to print on all four layers between the ceramic ink electrodes, but only on a few layers or a portion of them if necessary. Also.

There was no particular problem even if the printing position of the ink on the ceramics and the printing position of the electrodes partially overlapped.

Furthermore, if necessary, a calender treatment (pressing against a smooth metal plate or the like while applying pressure or heat to make one 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 embodiment, 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 a method for applying a ceramic slurry onto a support on which an electric source is formed, and then drying the ceramic slurry, thereby removing the electrolyte caused by the electrode portion generated at this time. The unevenness of the electrodes is filled by printing ceramic ink to produce a raw ceramic sheet with embedded electrodes.The raw ceramic sheet with embedded electrodes is then coated with other raw ceramic sheets or other electrodes without peeling off from the support. After 4 times of pressure bonding, the support is peeled off, and the electrode-embedded ceramic green sheet is transferred onto the other ceramic green sheet or another electrode, thereby forming a ceramic green sheet. Because it is handled together with the support, it does not suffer any damage during handling, and by printing ceramic ink on the concavities that occur when ceramic slurry is applied to the electrode, it is possible to improve the unevenness of the surface of the ceramic green sheet embedded in the ceramic sheet. Multilayer ceramic electronic components such as seven-layer ceramic capacitors can be manufactured with high yield while reducing generation.

[Brief explanation of the drawing]

1.1 (M) to (D) are diagrams for explaining the production of an electrode-embedded ceramic raw sheet according to an embodiment of the present invention, and Figures 2 and 3 are diagrams for explaining the production of an electrode-embedded ceramic green sheet according to an embodiment of the present invention. Figures 4 and 5 are diagrams for explaining how the green ceramic sheets are laminated, Figures 4 and 5 are diagrams showing modifications of the embodiments in Figures 2 and 3, and Figure 6 is a diagram showing a modification of the embodiment shown in Figures 2 and 3. Fig. 7 is a cross-sectional view of a part of a multilayer ceramic capacitor, and Fig. 8 is a cross-sectional view of a part of a multilayer ceramic capacitor in a conventional example. FIG. 9 is a cross-sectional view of a dipping ceramic capacitor when laminated, and FIG. 9 is a diagram illustrating the difference in thickness between the center portion and the peripheral portion with respect to the number of laminated layers. FIG. 10 is a diagram for explaining an example of the method for manufacturing a raw ceramic sheet with embedded electrodes, and a diagram for explaining a step in which the slurry of the dielectric material is dried. 11...ti, 12...base film, 13...first ceramic slurry 14
...ceramics ink, 16...
Second Ceramics'7) Slurry, 2o...
・Stand, 21.211L, 21 bo・°°°Base film, 22...Ceramic raw laminate, 23,
231L... Electrode, 24, 24L... Ceramic raw sheet, 26... Electrode embedded ceramic raw sheet, 26.26 &... Heater, 2
7...Heating plate, 28...Transferred electrode, 29,291...Ceramic ivy raw sheet shown, 3o...Transferred electric box embedded ceramic ...heat roller.

Claims (2)

[Claims] (1) After applying a ceramic slurry onto the support on which the electrode portion is formed, drying the ceramic slurry, and printing ceramic ink to remove the unevenness caused by the electrode portion generated at this time. to create a green ceramic sheet with embedded electrodes, and then the green ceramic sheet with embedded electrodes is thermocompression bonded onto another green ceramic sheet or another electrode without peeling off from the support. 1. A method for producing a laminated ceramic electronic component, comprising peeling off only the body 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.