JPH0258316A - Manufacture of laminated ceramic electronic component - Google Patents

Abstract

PURPOSE:To scarcely short-circuit electrode due to drying, and to transfer on a thin electrode buried ceramic crude sheet by flattening the surface of the sheet while holding its mechanical strength by forming the crude sheet on a support, thermally press-bonding it on another ceramic crude sheet or another electrode, then removing the support, and transferring it. CONSTITUTION:When an electrode ink film 10 formed on a support 11 made of a polyester film or the like is coated with a ceramic slurry 12, the coating is conducted only on the surface of the support 11 except a part covered with the film 10, and then dried as a first crude sheet 12a. This ceramic crude sheet 14 is pressed in contact with a ceramic laminate 15 together with the support 11, and the support 11 is removed to transfer the sheet 14 on the surface of the laminate 15. Since the sheet is buried in a state that the ink is dried and no solvent exists, the sheet is not eroded and not swelled.

Description

[Detailed Description of the Invention] Industrial Field of Application The present invention relates to a method for manufacturing multilayer ceramic electronic components such as multilayer ceramic capacitors that are widely used in electrical products such as video tape recorders and LCD television office automation equipment. In addition, it can be widely used in manufacturing multilayer ceramic electronic components such as multilayer ceramic substrates, multilayer varistors, and multilayer piezoelectric elements.

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 laminated ceramic electronic components to be further miniaturized and have higher performance.

Here, a multilayer ceramic capacitor will be explained as an example of a multilayer ceramic electronic component.

FIG. 3 is a cross-sectional view of a part of the multilayer ceramic capacitor. In FIG. 3, 1 is a ceramic dielectric layer, 2 is an internal electrode, and 3 is an external electrode. The inner electrodes 2 are alternately connected to two outer 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,
Mere reduction in area directly leads to a reduction in electrical capacity. For this reason, multilayer ceramic capacitors must be made smaller and more sophisticated at the same time.

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.

First, thinning of the dielectric layer will be explained. It is extremely difficult to make this dielectric thin. First, a method for manufacturing a multilayer ceramic capacitor will be briefly explained. First, a method for manufacturing a ceramic green sheet will be described.

The raw ceramic sheet used to manufacture this multilayer ceramic capacitor is a vehicle made by dissolving metal oxide powder, which serves as a dielectric, and resin such as polyvinyl butyral, polyvinyl alcohol, or polyacryloid in a solvent such as xylene. After uniformly dispersing the slurry into a slurry, it is continuously formed into a film as a ceramic green sheet with a thickness of a dozen or more microns to several tens of microns using a gear casting method (solution casting) at high speed. The gearing method used here uses a metal or organic film such as polyethylene terephthalate film C (hereinafter referred to as PET film) as a support, and uses a doctor blade etc. to spread the slurry onto this support to form a uniform layer. The slurry is applied to a film thickness and the solvent in the slurry is evaporated by hot air drying or natural drying to form a green ceramic sheet.

When manufacturing multilayer ceramic capacitors,
Next, after cutting this ceramic raw sheet into a predetermined size, electrodes are printed on the ceramic raw sheet, and multiple ceramic raw sheets including this printed ceramic raw sheet are laminated, pressed, cut, and fired. It will be created later.

Here, in order to make the dielectric layer thinner, it is necessary to make the raw ceramic sheet thinner, but the thinner the raw ceramic sheet, the more likely pinholes etc. will occur in the raw ceramic sheet. . For this reason, the yield of multilayer ceramic capacitors decreases rapidly due to the thinning of the raw ceramic sheet. In addition, the vehicle for both electrode ink and green ceramic sheet is a resin dissolved in a solvent. For this reason, when electrode ink is printed on a green ceramic sheet, the solvent in the electrode ink dissolves the resin of the green ceramic sheet. For this reason, the electrode ink printed on the green ceramic sheet erodes the green ceramic sheet, causing swelling and making short circuits more likely to occur.

For this example, combinations with less erosion and swelling are being considered by changing the type and amount of resin in the raw ceramic sheet, but when the thickness of the raw ceramic sheet becomes thinner, for example, 30 microns or less, erosion and There are almost no combinations that do not cause swelling. In addition, the combination of raw ceramic sheets that are less likely to erode or swell may cause the ink to dry too quickly when printing with 7E electrode ink, resulting in poor workability during printing, or the electrode ink may dry during the drying process after printing. It is difficult to obtain a combination that can be put to practical use due to phenomena such as cracks occurring or cracks occurring when the pressed laminate is sintered.

For this purpose, in practice, dielectric layers and internal electrodes are multilayered. However, in the conventional lamination method, when multilayering occurs, local thickness unevenness or step differences occur due to differences in the number of laminated layers in the internal electrode. Due to the unevenness caused by this thickness unevenness, it is not possible to laminate layers with a uniform thickness in a multilayer ceramic capacitor sheet, resulting in problems such as delamination (separation between layers) and cracks.

FIG. 4 is a cross-sectional view of a multi-layer ceramic capacitor when it is multi-layered. As shown in Figure 4, it can be seen that the thickness B of the periphery (where the number of internal electrodes 2 is small) is smaller than that at the center (where there are many internal electrodes 2) of the multilayer ceramic capacitor. FIG. 6 is a diagram illustrating the difference in thickness between the center portion and the peripheral portion with respect to the number of laminated layers. Here, the thickness of the ceramic raw sheet used was 2Q microns, and the thickness of the internal electrodes was 4 microns. From FIG. 5, 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.

Conventionally, several approaches have been taken to address this problem. First, in JP-A No. 52-135050 and JP-A No. 52-133553, a new ceramic green sheet from which the internal electrodes have been removed is inserted into the step part, that is, the peripheral part, and after this is laminated, it is fired. A method has been proposed. However, according to this method, it is necessary to remove the green ceramic sheet with high precision, for example, into a size of 3.5 mm x 1.0 mm, on several hundred sides or more. In particular, a raw ceramic sheet alone cannot be mechanically handled due to its thinness and softness. Even if it were possible to handle it, it would be difficult to punch it accurately.

Similarly, there is a manufacturing method for multilayer ceramic capacitors, as disclosed in Japanese Patent Application Laid-open No. 61-102719, in which both raw ceramic sheets and electrode sheets are punched and laminated one after another, but this also has problems in mass production. . For example, punching multiple times at one time is disadvantageous compared to printing in terms of cost and accuracy. Furthermore, if the thickness of the electrode sheet is 5 microns or less, the physical strength of the electrode notebook will not be able to withstand punching or handling.

However, in JP-A No. 62-135051, internal electrode ink is first applied on a green ceramic sheet, dielectric ink is further applied to the remaining area coated with internal electrode ink, and this is used to remove the internal electrode ink. Methods have been proposed in which the materials are placed in different positions, stacked, pressed, and fired. However, in this case, the problem remains that the underlying laminate is attacked by the solvent contained in the newly printed dielectric ink.

For this reason, the thinner the raw ceramic sheet is, the more likely it is to cause short circuits and deteriorate withstand voltage characteristics.

Further, as a method that does not use a solvent in the electrode ink, there is an electrode forming method such as that disclosed in Japanese Patent Application Laid-Open No. 53-51458. There is also a method using an electroless plating method using an activated paste, as disclosed in JP-A-57-102166, but in order to form electrodes using the electroless plating technique, a raw ceramic sheet is immersed in a plating solution. As a result, a new problem arises.

In addition, it has been considered to partially punch out a raw ceramic sheet or process it into a concave shape, as disclosed in Japanese Patent Application Laid-Open No. 53-42353, but this is not practical.

Furthermore, Japanese Patent Application Laid-Open No. 56-94719 is similar, and attempts to form a green ceramic sheet on the stepped portions of a laminate, and is unlikely to be suitable for mass production.

In addition, several methods have been proposed to prevent the adverse effect of the solvent in the electrode ink on the green ceramic sheet.

For example, as in Japanese Patent Application Laid-Open No. 56-106244, there is a method in which only electrodes are first printed on a base film, and then a green ceramic sheet is formed thereon by a catching 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, since the electrode-embedded ceramic green sheet made by these methods is peeled from the base film, 1 when the film thickness becomes thinner, the mechanical strength is extremely reduced, so that it can no longer be handled by itself. . For this reason, it was not possible to make the layer thinner than 20 microns.

Furthermore, the following method was also considered. Japanese Unexamined Patent Publication 1986-63
For ease of handling, JP 413 proposes a method in which electrode ink is printed on the surface of the green ceramic sheet while it is adhered to the base film, and after lamination, the base film is peeled off. However, if we consider the erosion of the green ceramic sheet by the electrode ink in this method, we will find that the thinner the ceramic green sheet becomes, the more easily it will be attacked by the electrode ink. Furthermore, since the opposite side of the green ceramic sheet (the side on which the electrode ink is not printed) is covered with the base film, the solvent of the electrode ink that has soaked into the green ceramic sheet cannot evaporate from this opposite side. It becomes impossible to do so and remains inside the raw ceramic sheet. In other words, the electrode ink remains on the green ceramic sheet for a longer period of time than in the past, making the green ceramic sheet more likely to be attacked by the electrode ink.

Next, JP-A-63-31104 and JP-A-63-
32909, the electrode ink is not printed on the surface of the raw ceramic sheet, but is thermally transferred.
A method has been proposed to increase the yield of multilayer ceramic capacitors by forming them on green ceramic sheets while preventing the adverse effects of electrode ink solvents. However, in this method, both the ceramic green sheets and the electrodes are alternately laminated by thermal transfer. That is, thermal transfer is repeated 50 times for stacking internal electrodes and 60 times for stacking electrodes, a total of 10 times or more.

Furthermore, if there is only one layer of green ceramic sheet, there is a high possibility that pinholes will occur. Therefore, in order to increase the yield,
Continuous two-layer transfer of a green ceramic sheet is considered. However, in this case, thermal transfer will be repeated a total of at least 160 times or more.

This means that each transferred layer has a different thermal history. That is, the first thermally transferred layer is then 15
Thermal history is added nearly 0 times. On the other hand, the last stacked layers are only subjected to several subsequent thermal cycles. Generally, each time such a thermal history is applied, the green ceramic sheet is thermally deformed little by little. Furthermore, the layer that is thermally transferred first has a larger thermal history and is more deformed than the layer that is laminated last. As a result, the raw ceramic sheet may become deformed, its thickness may change, or the stacked positions of the electrodes may shift.

Defects are likely to occur when cutting after lamination.

Furthermore, in Japanese Patent Application Laid-open No. 63-51616, an electrode in a predetermined pattern is provided on one side of a film, and the film with the dried electrode is placed on a green ceramic sheet so that the electrodes overlap. A method for manufacturing a multilayer capacitor has been proposed, which is characterized by thermally transferring the ceramic raw material onto a sheet, laminating a plurality of raw ceramic sheets, and firing the ceramic raw sheets. However, with this method, the raw ceramic sheet is subject to thermal history, resulting in poor accuracy. Further, the electrodes are not transferred onto a dimensionally rigid base film, but are thermally transferred onto a heat-softening green ceramic sheet, and then onto a green ceramic sheet. At this time,
There is a high possibility that not only the raw ceramic sheet but also the base film will be thermally deformed during electrode transfer.
In this case, the lamination accuracy is further deteriorated. Therefore, in this method, it is essential to use a base film with excellent heat resistance, which increases manufacturing costs.

Furthermore, in Japanese Patent Application Laid-Open No. 63-61617, the electrodes are transferred by heating and pressing a film onto a green ceramic sheet using a pressing die equipped with protrusions that match the electrode pattern, and transferring a predetermined pattern of electrodes from the electrode layer to the ceramic sheet. It will be transferred to a raw sheet. However, in this case, when a protrusion is used, the thickness of the green ceramic sheet inevitably changes at that part. Furthermore, as many protrusions as the number of electrodes are required, the pressure at each protrusion inevitably varies. For this reason, the thickness or compressibility of the green ceramic sheet varies at each electrode position. Additionally, there is a pressure distribution at the protrusion where one electrode is transferred (generally called the marginal zone, which is the cause of uneven ink density in letterpress printing). Thickness changes.

Furthermore, both the ceramic raw sheet itself and the base film on which the ceramic raw sheet is formed are subject to partial thermal pressure before being laminated, so that they tend to undergo irregular deformation. Further, as in JP-A-63-51516, the electrodes are thermally transferred not onto a dimensionally solid base film but onto a heat-softening green ceramic sheet and then further thermally transferred. At this time, not only the raw ceramic sheet but also the base film are thermally deformed during the thermal transfer of the electrodes, resulting in a product of .1 deterioration in accuracy. Therefore, it is essential to use a base film with improved heat resistance, which increases manufacturing costs.

In addition, as a method for manufacturing multilayer ceramic capacitors by embedding electrodes in raw ceramic sheets,
There are Japanese Patent Publication No. 24226 and Japanese Patent Publication No. 56-37619. However, these manufacturing methods involve printing multiple layers of dielectrics and 'IIL electrodes alternately on one base film using a method such as gravure printing.
J. Therefore, there is a problem that the green ceramic sheet is immersed in the solvent contained in the -■ electrode.

Furthermore, Japanese Patent Publication No. 69-172711 proposes a method of manufacturing a multilayer ceramic capacitor by embedding electrodes formed on a base film in a raw ceramic sheet, laminating the base film together, and firing. However, in order to fire the entire base film, it is necessary to use a very thin base film with a thickness of about 1.5 to 14 microns. Furthermore, the number of base films to be fired increases in proportion to the number of laminated layers, which makes delamination more likely to occur. For this reason, the base film needs to be made thinner as the number of layers increases. Furthermore, base films made of resins that are easily fired have poor mechanical strength. Therefore, this lamination method has a problem that it cannot be used in an automatic lamination apparatus or the like.

In addition, as a transfer method that does not use a solvent, JP-A-63-5
As in Japanese Patent No. 3912, an electrode paste containing an ultraviolet curable resin, which will become an internal electrode, is formed on an ultraviolet-transparent carrier film, and the electrode paste is irradiated with ultraviolet rays through the carrier film of the 01 process. Curing the ultraviolet curable resin on the side of the electrode paste film that is in contact with the carrier film, and keeping the ultraviolet curable resin on the other side in an uncured or semi-cured state;
There is a method for forming internal electrodes of a ceramic laminate in which the electrode paste is transferred to and laminated onto a raw ceramic sheet. However, in this method, the electrode ink is cured only on the carrier film side, and the surface side of the electrode ink (the side that is not the carrier film) is uncured or semi-cured and has adhesive properties. The surface of such so-called half-dry iTi and polar ink is difficult to handle, as it is easy to collect dust and dirt even from the slightest thing. still,? l'l: After applying the polar ink, the carrier film cannot be wound up because the surface is half-dry. After transferring the electrode paste to the green ceramic sheet, the green ceramic sheet will be laminated without being held by a carrier film. For this reason, when the thickness of the green ceramic sheet becomes less than about 20 microns, the mechanical strength of the green ceramic sheet itself becomes insufficient and it becomes impossible to handle it. For this reason,
There is a limit to how thin a ceramic itE sheet can be made by this method.

Furthermore, if electrodes are simply embedded in a raw ceramic sheet, the thinner the ceramic raw sheet becomes, the more unevenness caused by the electrodes will remain on its surface. This will be explained using FIGS. 6(A), (B), and (C). FIGS. 6A, 6B, and 6C are diagrams for explaining how the electrode ink film formed on the support is embedded in the green ceramic sheet. In Figure 6, 4
5 is a support, 5 is an electrode ink, 6 is an electrode ink sample, and 7 is a green ceramic sheet made of dried ceramic slurry. Without separating, the electrode ink 6 is formed on the support 4 by a method such as printing as shown in FIG. 6(A). Next, as shown in FIG. 6(B), a ceramic slurry is applied onto the support 4 on which the electrode ink 1 and 6 formed by drying the electrode ink 6 are formed. Next, Figure 6 (C
), the ceramic slurry dries to become a green ceramic sheet 7, which embeds the electrode ink film 6, and causes unevenness on the surface of the ceramic green sheet 7 due to the embedded electrode ink film 6. here,
In order to prevent the occurrence of this unevenness, the inventors changed the component ratio of the ceramic slurry or changed the method of applying the ceramic slurry, but no significant improvement was achieved. Furthermore, it is thought that these irregularities are essentially generated when the volume of the ceramic slurry changes as it dries, and it is thought that the irregularities are more likely to occur as the film thickness of the green ceramic sheet becomes thinner.

Problems to be Solved by the Invention Therefore, in the structure of a multilayer ceramic capacitor as described above, in a method for manufacturing a multilayer ceramic capacitor in which electrodes are printed on a ceramic sheet, the raw ceramic sheet is eroded by the solvent contained in the electrode ink. The thinner the ceramic sheet, the easier it will be to shake. On the other hand, in the manufacturing method of a multilayer ceramic capacitor using the electrode-embedded ceramic raw sheet in which the electrode is embedded in the ceramic raw sheet, m
By peeling off the electrode-embedded ceramic sheet from the support, there was a limit to how thin the layer could be. Also,
If electrodes were simply embedded in a ceramic green sheet in order to prevent the adverse effects of the solvent, unevenness caused by the electrodes would occur on the surface of the ceramic green sheet. For this reason, especially when multilayering dielectric layers and internal electrodes, there is a problem in that it is impossible to eliminate the level difference caused by the internal electrodes between the center and the periphery of the multilayer ceramic capacitor. Ta.

In view of the above-mentioned problems, the present invention has been developed by embedding the electrodes in a ceramic green sheet, making it difficult to cause short circuits due to the dryness of the electrodes, and flattening the surface of the ceramic green sheet. Even when used to manufacture multilayer ceramic capacitors with multilayered layers and internal electrodes, it reduces the level difference caused by the internal electrodes between the upper middle part and the peripheral part of the multilayer ceramic capacitor, and reduces the height difference to about 20 microns or less. The present invention provides a method for manufacturing a laminated ceramic electronic component that can be handled and transferred while maintaining mechanical strength even in a thin raw ceramic sheet.

Means for Solving the Problems In order to solve this problem, the present invention applies a ceramic slurry to a support on which electrodes containing a fluororesin are formed and dries it, and then forms a ceramic slurry with electrodes embedded on the support. A sheet is made, and then the electrode-embedded ceramic raw sheet is thermocompressed onto another ceramic raw sheet or another electrode without peeling from the support, and then the support is removed and the electrode-embedded ceramic sheet is bonded to another ceramic raw sheet or another electrode. The present invention has a configuration in which a raw ceramic sheet is transferred onto the other raw ceramic sheet or another electrode.

Effect: With the above-described structure, the present invention embeds the electrode ink in the ceramic raw sheet in a state where the electrode ink is dried and the solvent is gone, so that the ceramic raw sheet is prevented from being eroded or swollen by the solvent contained in the electrode ink. . In addition, since the raw ceramic sheet with embedded electrodes can be handled while it is formed on the support until it is laminated, it is possible to handle the raw ceramic sheet (raw ceramic sheet with embedded electrodes) even if it becomes thin, and it can be supported until the lamination is completed. Since the body can hold the raw ceramic sheet, the lamination accuracy can be improved.

Furthermore, by embedding the electrodes in the ceramic raw sheet, it is possible to reduce the occurrence of unevenness caused by the electrodes on the surface of the ceramic raw sheet.

Particularly, in the present invention, by pre-containing a fluororesin in the electrode ink, it is intended to further prevent unevenness caused by the electrodes from occurring on the surface of the raw ceramic sheet. In other words, the surface chemical action of the fluororesin contained in the 'KW ink film makes it difficult for the electrode ink film to be wetted by the ceramic slurry. The ceramic slurry coated on the electrode ink film is repelled (or removed), thereby reducing the film thickness of the ceramic slurry on the electrode ink film (
Alternatively, by partially or completely removing the electrodes, the occurrence of unevenness on the surface of the ceramic sheet caused by the electrodes can be further prevented. In this way, unevenness can be prevented from occurring even if the film thickness is thinner than that of conventional electrode-embedded ceramic green sheets.

Example The present invention will be described below with reference to Examples.

First, a method for manufacturing a multilayer ceramic capacitor according to an embodiment of the present invention will be described with reference to the drawings.

Figures 1 (A), (E), (C), Φ) are diagrams showing an example of the method for manufacturing a raw ceramic sheet with embedded electrodes to explain the present invention, and Figures 2 (A), (B) )
FIG. 3 is a diagram for explaining a method of manufacturing a @layer ceramic capacitor in an embodiment of the present invention. In FIG. 1, numeral 10 is an upper electrode ink containing a fluororesin; numeral 11 is a support; numeral 12 is a first ceramic slurry; numeral 121L is a first green sheet; 13 is a second ceramic slurry 13 & is a second green sheet, which is made by drying the second ceramic slurry 13.

14 is a raw ceramic sheet with embedded electrodes.

First, as shown in Figure 1), the polyester film diagram (
Cases such as B) or (C) may occur, and the state shown in FIG. 1 @) is strictly speaking the state that has passed through the state shown in FIG. 1 (C). Even if the state shown in Fig. 1 (B) or the state shown in Fig. 1 (q) occurs, it is still possible to prevent the occurrence of unevenness due to the electrode. If the first ceramic slurry 12 is not applied on the membrane 10, the first ceramic slurry 12 is dried to form a first raw material 12a.
After that, a second ceramic slurry 13 is applied as shown in ) in FIG. can be made.

Here, the second ceramic slurry 13 can also be applied onto the electrode coating film 1o by changing the content and type of the first ceramic slurry 12 and its solvent. In the case of FIG. 1C, the second ceramic slurry 13 may be applied as necessary.

Next, using FIGS. 2A and 2B, an electrode ink coating 1o is formed on the support 11 in which the electrodes are embedded. This 'mixed polarity ink sample 10 transfers the electrode ink to the support 11.
Obtained by drying or curing the electrode ink after printing on it. However, as a printing method for the electrode ink, printing methods such as screen printing, offset lithographic printing TA11, offset letterpress printing, flexographic letterpress, thermal transfer, and inkjet printing can be used. Next, add the first
When the first ceramic slurry 12 is applied, each electrode ink is coated with the first ceramic slurry 12.
1 (B), the first ceramic slurry 12 is applied to the surface of the support 11 other than the part covered with the E electrode in-in 10, as shown in FIG. 1(B). After drying, it becomes the first raw material 7-) 12&. 1st
Figure (q) is for explaining the case where the first ceramic slurry 12 coated on the electrode ink film 1o is attached to the entire surface of the support 11 including the electrode ink film 1Q. Now, a method for manufacturing a multilayer ceramic capacitor using the first raw ceramic sheet 14 will be explained depending on the type and condition of the fluororesin ht and the ceramic slurry contained in the electrode ink film 10. In FIG. This is a green laminate, and green ceramic sheets are laminated in advance. 16 is a press device. First, as shown in FIG. The embedded ceramic raw sheet 14 is sandwiched.Next, the press device 1
6, the electrode-embedded ceramic green sheet 14 is pressed together with the support 11 against the ceramic green mPM body 15.

At this time, it may be pressed while applying heat. Next, the second
As shown in Figure (B), by peeling off the support 11,
The electrode-embedded ceramic green sheet 14 is transferred onto the surface of the ceramic green laminate 15. At this time, an electrode may be provided on the ceramic raw laminate 16 in advance and the electrode may be transferred thereon.

Next, it will be explained in more detail.

First, a polyester film with a thickness of 75 microns was used as the support of the present invention. Next, on this support, a fluororesin diversion (0,
After printing an electrode ink containing 5 layers (2 to 0.3 microns) using a screen printing method, heat treatment was performed to cure the fluororesin to form an electrode ink film. Here, the electrode ink was made of palladium powder with a particle size of 0.3 microns.
0 parts by weight of ethyl cellulose as a resin, and 0.1 parts of heavy oil as a dispersant, butyl calpitol was added as a solvent to obtain an appropriate viscosity, and the viscosity was adjusted using a Miki roll mill. I made it by dispersing it until it became 100 voices. Next, electrode ink was printed on the support by a screen printing method. Further, when the thickness of the dried electrode ink film after calendering was measured, it was 9 microns. Hereinafter, this will be referred to as the 1F pole of the present invention.

For comparison, as a conventional method, an electrode ink containing no fluororesin was similarly prepared, printed and calendered in the same manner, and used as a conventional electrode.

Next, a ceramic slurry was applied onto the electrode of the present invention and the conventional electrode. First, we will explain how to make ceramic slurry. This was added together with 31.0 parts by weight of barium titanate powder with a particle size of 1 micron to a resin solution containing polyvinyl butyral resin (Sekisui Chemical Co., Ltd. So, BL-2 Butyral Resin), plasticizer, and solvent, and stirred well. did. Next, put this in a polyethylene bottle,
Zirconia beads were added and mixed and dispersed until a suitable dispersion state was obtained. Next, after temporarily filtering this, it is filtered under pressure using a 10 micron membrane filter, and 't'r
A slurry of the first and second ceramics was prepared. At this time,
The amount of solvent added was changed between the first ceramic slurry and the second ceramic slurry.

Next, the slurry of these two types of ceramics was coated on the electrode of the present invention and the conventional electrode using a coating device using a barcoder. When the film thickness was measured with a meter, it was found that the film thickness of the single ceramic green sheet formed by drying the ceramic slurry was 18 microns.

Next, a method for manufacturing a laminated ceramic capacitor using this electrode-embedded ceramic green sheet will be described. First, as shown in FIG. 2, electrode-embedded ceramic green sheets were successively transferred and laminated onto a ceramic green laminate having a thickness of 200 microns on which no electrodes were formed. Furthermore, by transferring the next electrode-embedded raw ceramic sheet with a certain pitch shifted during stacking, the internal electrodes were alternately shifted.

Thereafter, this was repeated so that the internal electrodes were alternately shifted as shown in FIG. 3, so that the internal electrodes were heated to 10K.

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 cut into chips and then fired at 1000° C. for 1 hour.

Next, external electrodes were formed using a conventional method, and the effect of thinning the uneven layer due to the electrodes was investigated. The results are shown in Table 1 below. In Table 1, on the support is the thickness of the electrode itself after drying, after embedding is the unevenness after drying after coating the surface with ceramic slurry, and after lamination is the unevenness of the green laminate after laminating 10 layers. It is.

As shown in Table 1, it can be seen that by adding a fluororesin to the electrode ink, the occurrence of unevenness in the electrode-embedded ceramic raw sheet and the laminate is greatly improved compared to the conventional electrode. Furthermore, when a multilayer ceramic capacitor with a high lamination of 5oFJ or more was prototyped and evaluated, the production method of the present invention showed a low incidence of delamination (separation between layers) and the like.

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. In addition, this thermal transferability is due to polyvinyl butyral resin (hereinafter referred to as
The less the amount of PVB resin (called PVB resin), the worse the transferability.
Conversely, the more PVB resin is included, the better the transferability becomes. The PVB resin contained in the raw ceramic sheet used here was
Those containing about 20 grams had good transferability.

However, the amount of PVBI resin h'c required for transfer depends on the particle size of the ceramic powder used as the slurry raw material, the degree of polymerization and type of PVB resin, or the temperature at the time of transfer. The amount is changed and the amount is changed. If the amount of resin is insufficient, it is necessary to lower the transfer temperature.

Next, regarding the barium titanate powder with the particle size used in the experiment, the resin contained in the raw ceramic sheet, rit (
! : The results of an experiment regarding the transferability of this ceramic raw sheet are shown in Table 2 below. Here, as mentioned above, the ceramic raw sheet is made of barium titanate powder, dibutyl phthalate as a plasticizer, and PVB resin, and the transferability when the weight percentage of the PVB resin contained therein is changed. Examined. Here, the amount of diptyl phthalate added to the ceramic green sheet is 1 of the PVB resin.
It was fixed at 0% by weight. Regarding the transferability of the raw ceramic sheet, an experiment was conducted by transferring the raw ceramic sheet with embedded electrodes onto the raw ceramic laminate as shown in Fig. 2. The transfer was performed from the support side at a transfer pressure of 15 kilograms per square meter and at a temperature of 180'.
This was done by pressing a heated hot plate against C. Also, P
'/B The amount of resin was expressed in terms of weight in the raw ceramic sheet.

(Leaving space below) Table 2 Table 3 Next, Table 3 shows the results of investigating the relationship between the amount of PvB resin contained in the green ceramic sheet and the incidence of delamination using the green ceramic sheet in Table 2 above. Shown in the table. Note that the number of laminated layers was 6o.

(Margin below) From Table 3, it was found that delamination is less likely to occur when the amount of PVB resin is from 10% by weight to 40% by weight. From the above, it can be seen that the PVB resin-resinated lamic raw sheet with a thickness of 10% to 40%, especially around 16% by weight, has good transferability and less occurrence of delamination.

Here, as resins having transferability like PVB resins, there are other thermoplastic resins such as acrylic resins, vinyl resins, and cellulose derivative resins.

In addition to thermoplastic resins, curable resins and polymerizable resins can also be cured and polymerized under appropriate curing and polymerization conditions.For example, by making them rubber-like and giving them adhesiveness on the surface, it is possible to It can be used as a plastic resin.

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.

Furthermore, it goes without saying that the ceramic slurry of the present invention can be applied using a gravure coating machine or a reverse coating machine. Coating machines actually used for magnetic tape production (for film thicknesses of 1 to 4 microns)
Ceramic slurry was applied onto the electrode ink film using a coating speed of several meters per minute, but there were no problems. In this case, the uniformity of the film thickness of the ceramic slurry can be made as good as that of magnetic tape, and furthermore, it can be applied at high speed.

As for the fluororesin added to the electrode ink, F E
In addition to the 0.2 to 0.3 micron dispersion of P4tt resin ('fluorinated ethylene-67 propylene copolymer resin), fluororubber or the like may be used. It is also effective to mix and use materials with high releasability such as silicone resin and wax. Also, good results were obtained in terms of firing when the amount of fluororesin added was about 0.5 weight range to 3 o weight range. Here, if the amount of silicone resin added is 4o by weight, delamination will occur,
In addition, the above-mentioned repelling effect could not be obtained in the case of 0 and 1 weight class. In particular, in the present invention, depending on the properties of the ceramic slurry (viscosity, temperature, amount of solvent, type of solvent, etc.),
The required amount of fluororesin added to the electrode varies widely. In particular, the solvent for ceramic slurry is not only an organic solvent but also a substance with high surface tension such as water, and if necessary, alcohol etc. Can change gender. Further, it is also effective to perform primer treatment as a chemical example and corona discharge as a physical example to make the surface of the support more easily wetted by the ceramic slurry.

Furthermore, even if the electrode ink film containing fluororesin becomes wet due to ceramic slurry, it can be repelled stably by blowing air using an air doctor or by applying it vertically. or the film thickness can be reduced. Furthermore, the fluororesin may be added to the surface after printing the electrode ink, and in this case, it is effective to reduce the amount h1 of the fluororesin added.

Furthermore, 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 a method of coating a ceramic slurry on a support on which electrodes containing a fluororesin are formed, drying it, producing a raw ceramic sheet with electrodes embedded on the support, and then After the electrode-embedded ceramic raw sheet is thermocompressed onto another ceramic raw sheet or another electrode without peeling from the support, the support is removed and the electrode-embedded ceramic raw sheet is bonded to the functional material. By transferring onto a green ceramic sheet or other electrode, the negative effects of the solvent contained in the electrode ink can be prevented, and since the green ceramic sheet is handled together with a support, it will not be damaged during handling. Multilayer ceramic electronic components such as multilayer ceramic capacitors can be manufactured with high yield while embedding the electrodes and reducing surface chemical irregularities caused by internal electrodes.

[Brief Description of the Drawings] Figures 1 (A), (B), ((1) and (D) are diagrams showing, in order of process, an example of a method for manufacturing a raw ceramic sheet with embedded electrodes for explaining the present invention. , Figure 2 (A),
(B> is a diagram for explaining the manufacturing method of a multilayer ceramic capacitor in an embodiment of the present invention, FIG. 3 is a cross-sectional view of a part of a multilayer ceramic capacitor, and FIG. 4 is a multilayer ceramic capacitor in a conventional example. Figure 5 is a cross-sectional view of the laminated ceramic capacitor when the laminated ceramic capacitor is laminated. It is a diagram illustrating how the slurry electrode ink film of the π-S press is embedded in the ceramic green sheet. 10... Electrode ink film, 11... Support, 12. ...First ceramic slurry, 1
21L first raw sheet, 13... second ceramic slurry, 13a... second raw sheet,
14... Ceramic raw sheet with embedded electrode, 15
...Ceramic raw laminate, 16...Press device. Name of agent: Patent attorney Shigetaka Awano and 1 other person Electrode ink film No. 3 Ih-・-Raw sheet diagram of Army 2? Foil 4 Figure Number of laminated layers (・1) Figure

Claims (3)

[Claims] (1) On a support on which an electrode containing a fluororesin is formed,
A ceramic slurry is applied and dried to form a raw ceramic sheet with embedded electrodes on the support, and then the raw ceramic sheet with embedded electrodes is coated with another raw ceramic sheet or another electrode without peeling off the raw ceramic sheet with embedded electrodes from the support. 1. A method for manufacturing a laminated ceramic electronic component, characterized in that after thermocompression bonding, the support is removed, and the electrode-embedded ceramic raw sheet is transferred 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. (3) A method for manufacturing a multilayer ceramic electronic component, characterized in that the fluororesin is blended in the electrode in an amount of 0.6% by weight or more and 30% by weight or less.