JPH0745471A - Fabrication of transfer metal film supply and multilayer ceramic electronic component - Google Patents

Abstract

PURPOSE:To provide a method for fabricating a transfer metal film supply in which the delamination from a supporting film can be controlled highly accurately. CONSTITUTION:The method for fabricating a transfer metal film supply comprises a step of forming a first film of such metal as can be etched relatively easily on a supporting film 1, a step of forming a second film 3 of such metal as can not be etched easily on the first metal film 2 by a thin film forming method, and a step patterning a laminated metal film 4 by etching to obtain a transfer metal film 4A.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a transfer metal film supplier suitable for transferring a patterned metal film, and a method for manufacturing a laminated ceramic electronic component using the transfer metal film supplier. In particular, a method for manufacturing a transfer metal film supply body capable of easily controlling the releasability of the transfer metal film from the support film, and a multilayer ceramic electronic component using such a transfer metal film as an internal electrode. Regarding the method.

[0002]

2. Description of the Related Art In recent years, with the miniaturization of electronic equipment, high-density mounting of electronic components has been promoted, and accordingly, further miniaturization of electronic components such as multilayer capacitors is desired. There is.

A conventional method of manufacturing a monolithic ceramic electronic component will be described by taking a monolithic capacitor as an example. First, a ceramic green sheet is formed on a polyethylene terephthalate (hereinafter PET) film by using a sheet forming method such as a doctor blade method. Next, for example, a conductive paste containing a metal powder such as palladium, silver-palladium alloy, or nickel is applied to the above ceramic green sheet by screen printing or the like so as to have a predetermined pattern. Next, a plurality of ceramic green sheets on which the conductive paste is printed are laminated, and the ceramic green sheets are pressed against each other by pressing in the thickness direction to obtain a mother laminated body. Thereafter, the obtained mother laminated body is cut in the thickness direction to obtain a laminated body of each laminated capacitor unit. Further, the obtained individual laminated bodies are fired to sinter the ceramics and the above conductive paste to complete the internal electrodes, and the conductive paste is applied and baked on both end faces of the obtained sintered body. Thus, a multilayer capacitor is obtained.

In order to realize a high capacity in the multilayer capacitor, it is necessary to reduce the thickness of the dielectric ceramic layer between the internal electrodes and increase the number of internal electrodes. In this case, to obtain a smaller size and higher capacity,
It is essential to reduce the thickness of the dielectric ceramic layer between the internal electrodes. Therefore, a thinner ceramic green sheet may be used as the ceramic green sheet used in the above manufacturing method.

However, the conductive paste contains a solvent. This solvent may swell or dissolve the ceramic green sheet and cause problems such as a short circuit between internal electrodes and a decrease in withstand voltage. Therefore, in order to prevent the adverse effect of the solvent in the conductive paste, it is necessary to use a ceramic green sheet having a certain thickness, and there is a limit in thinning the ceramic green sheet.

As a solution to the above problems,
There has been proposed a method of forming an internal electrode of a monolithic ceramic electronic component by a metal film formed by a thin film forming method such as vapor deposition / sputtering or plating (for example, JP-A-60-83315 and JP-A-64-63). 42809). In these methods, since the internal electrodes are composed of a metal film formed by a thin film forming method, the internal electrodes do not contain a solvent. Therefore, a thinner ceramic green sheet can be used because it does not cause swelling or dissolution of the ceramic green sheet.

In the above-mentioned prior art method, specifically, a metal film is formed by a thin film forming method on a supporting film made of an organic synthetic resin or the like, patterned by etching, and then, on the patterned metal film. A ceramic green sheet is molded to obtain an internal electrode laminated ceramic green sheet supply body. After that, a step of stacking the above-mentioned internal electrode laminated ceramic green sheet supply body on another ceramic green sheet, pressurizing, and peeling off the supporting film is repeated to obtain a laminated body.

Alternatively, a metal film formed by a thin film forming method on a support film is etched and patterned to form an electrode pattern, and then the electrode pattern is laminated on a separately prepared ceramic green sheet to form a support film. By repeating the method of transferring the electrode pattern by peeling off, the mother unfired laminate is obtained.

[0009]

DISCLOSURE OF THE INVENTION Problems to be Solved by the Invention
In the method disclosed in JP-A-83315 or JP-A-64-42809, the electrode pattern formed by the thin film forming method is peeled off from the supporting film together with the ceramic green sheet, or only the electrode pattern is peeled off from the supporting film. Is transcribed. Therefore, the metal film formed by the thin film forming method needs to be easily and reasonably peeled from the supporting film.

However, it was actually very difficult to control the releasability of the above metal film from the support film. In particular, when a ceramic green sheet is laminated on a metal film and the metal film is peeled off and transferred from the supporting film together with the ceramic green sheet, if the metal film has poor releasability, the ceramic green sheet and As the metal green film separates or the ceramic green sheet becomes thinner, the ceramic green sheet often breaks during transfer. Conversely, depending on the metal used,
Although the adhesion to the supporting film becomes too low and peeling can be performed easily, there is a possibility that a positional deviation occurs on the supporting film during transfer, causing problems such as a short circuit between internal electrodes and a decrease in withstand voltage.

An object of the present invention is to solve the above-mentioned drawbacks of the prior art and to manufacture a transfer metal film supply body capable of controlling the transferability of a metal film formed by a thin film forming method with high accuracy, and a method for manufacturing the same. Another object of the present invention is to provide a method for manufacturing a monolithic ceramic electronic component using another transfer metal film supply body.

[0012]

According to a first aspect of the present invention, there is provided a step of forming a first metal film made of a metal which is relatively easily etched on a support film by a thin film forming method, and the first film. Forming a laminated metal film by forming a second metal film made of a metal that is relatively difficult to be etched on the metal film of 1. by a thin film forming method, and patterning the laminated metal film by etching to form a transfer metal. And a step of obtaining a film supply body.

In the invention described in claim 1, as the support film, a film made of an appropriate synthetic resin conventionally used for forming a transfer metal film, for example, polyethylene terephthalate, polypropylene or the like is used. However, as a supporting film, 100
It may be made of a synthetic resin other than this or a material other than the synthetic resin as long as it is a material which is hard to be deformed at a temperature of about ° C.

In the present invention, a first metal film made of a metal which is relatively easy to be etched is formed on the support film by the thin film forming method, and further, the first metal film is relatively etched on the first metal film by the thin film forming method. A second metal film made of a metal that is difficult to be formed is formed to form a laminated metal film. In this case, as the thin film forming method, a conventionally known thin film forming method such as vapor deposition / sputtering or plating can be used.

As the metal forming the first and second metal films, it is preferable to use an appropriate metal in a combination of a metal that is relatively easily etched and a metal that is relatively difficult to be etched as described above. it can. For example, if Cu is used as the first metal film, a metal that is more difficult to etch than Cu, for example, Ni is used as the metal that forms the second metal film. However, as long as the above relationships are maintained, various combinations of metal materials can be used to form the first and second metal films.

The thicknesses of the first and second metal films are appropriately determined depending on the intended use of the transfer metal film and are not particularly limited, but they are metal films formed by a thin film forming method. Usually, it is formed to a thickness of 3 μm or less. Also, preferably, as described in claim 2, the first
When the thickness of the metal film of ₁ is t ₁ and the thickness of the second metal film is t ₂ , t ₁ / t ₂ is in the range of 1/50 to 1/5. By selecting such a range, that is, by making the thickness of the second metal film thicker than that of the first metal film, the second metal film is formed as a metal for obtaining the desired characteristics. By using the relatively thin first metal film only for controlling the peeling property of the second metal film, it is possible to configure the optimum transfer metal according to the application.

According to the first aspect of the present invention, after the laminated metal film composed of the first and second metal films is formed, the laminated metal film is patterned by etching. This etching is performed by an etchant capable of etching the first and second metal films, such as an acid such as nitric acid or sulfuric acid or Fe.
An oxidizing solution such as a Cl ₃ aqueous solution can be used.
Since the first metal film is more easily etched than the second metal film, the etching progresses faster in the first metal film. That is, etching progresses from the side surface of the first metal film, and as a result, the area of the first metal film becomes smaller than that of the second metal film. Therefore, when the transfer metal film is peeled from the support film and transferred, the area of the first metal film in contact with the support film is reduced, so that the laminated metal film can be smoothly peeled from the support film. it can.

Therefore, by controlling the etching time, the area of the portion of the first metal film which is in contact with the support film can be controlled, so that the peelability of the laminated metal film from the support film can be highly accurately achieved. Can be controlled.

According to a third aspect of the present invention, the transfer metal film supplying body obtained by the first aspect of the invention is used,
A method for manufacturing a monolithic ceramic electronic component. That is, an unfired ceramic sheet is formed on the transfer metal film supply body, and a transfer metal film laminated ceramic sheet is formed on the support film. In this case, the unfired ceramic sheet is formed by forming the ceramic green sheet by a doctor blade method so as to cover the transfer metal film on the support film, or by covering the transfer metal film on the support film. An appropriate unfired ceramic sheet forming method such as a method of applying a ceramic paste and curing it can be adopted.

According to the third aspect of the present invention, the transfer metal film laminated ceramic sheet obtained as described above is laminated on another unfired ceramic sheet. The other unfired ceramic sheet may be the transfer metal film laminated ceramic sheet obtained as described above, or may be an unfired ceramic sheet such as a ceramic green sheet in which the transfer metal film is not laminated. It may be. In any case, a mother unfired laminate is obtained by repeating the step of laminating the transfer metal film laminated ceramic sheets.

According to the third aspect of the present invention, since the transfer metal film laminated ceramic sheet is constructed by using the transfer metal film supply body of the first aspect as described above, the metal film laminated ceramic sheet for transfer is formed on the support film. The releasability of the transfer metal film laminated ceramic sheet can be controlled with high accuracy as in the case of the first aspect of the invention. That is, by controlling the etching time, the releasability of the metal film from the support film can be controlled with high accuracy, so that the transfer metal film can be smoothly and stably released together with the unfired ceramic sheet. .

The steps after obtaining the above-mentioned mother laminated body can be carried out according to a conventionally known method for producing a laminated ceramic electronic component. That is, the mother laminated body is cut in the thickness direction to obtain an unfired raw chip of each monolithic ceramic electronic component unit, the unfired raw chip is fired, and a predetermined external electrode is provided to the obtained sintered body. By doing so, a monolithic ceramic electronic component can be obtained.

Incidentally, also in the invention described in claim 3,
As described in claim 4, it is desirable that the thicknesses of the first and second metal films are such that t ₁ / t ₂ is in the range of ₁ to 50 to 1/5. That is, the second metal film is made of a metal suitable for use as an internal electrode, and the first metal film for controlling the peeling property is more etched than the metal of the second metal film. When using easy metals,
By setting the thickness ratio of the second metal film in the above range,
A monolithic ceramic electronic component having desired characteristics can be easily obtained.

[0024]

In the method of manufacturing the metal film supply body for transfer of the present invention, the first and second layers formed by the thin film forming method are used.
Since the easiness of etching the metal film of the above is related as described above, when the laminated metal film is patterned by etching, it is possible to adjust the etching time of the first metal film to the support film. The contact area can be controlled with high accuracy. Therefore, the releasability of the transfer metal film from the support film can be controlled with high accuracy.

Further, in the invention described in claim 2,
The ratio of the thicknesses t ₁ and t ₂ of the second metal film is selected within the above specific range, and the film thickness of the second metal film is made considerably larger than the film thickness of the first metal film. Therefore, by forming a metal film made of a metal material for exhibiting desired characteristics as the second metal film, and selecting the material for the first metal film in consideration of only the above etching property, It is possible to provide a transfer metal film capable of exhibiting the above characteristics.

According to the invention of claim 3, an unfired ceramic sheet is formed on the transfer metal film supply body of the invention of claim 1, whereby a transfer metal film laminated ceramic sheet is formed on the support film. Is configured. Therefore,
Also in this metal film laminated ceramic sheet for transfer, since the contact area of the first metal film with the support film is controlled with high accuracy by controlling the etching time, it is possible to stack the thin ceramic sheets. Also, the metal film laminated ceramic sheet can be peeled off from the supporting film without causing breakage of the ceramic sheet.

Similarly, in the invention described in claim 4, as in the invention described in claim 2, the thicknesses of the first and second metal films are selected in the above-mentioned specific relationship. Therefore,
By using a metal material suitable for drawing out the desired characteristics as the second metal film and selecting the metal material as the first metal film only in consideration of the above-mentioned etching property, the metal film alone is separated from the support film. It is possible to form a monolithic ceramic electronic component by using an internal electrode made of a metal film that cannot be smoothly processed.

The method for manufacturing a monolithic ceramic electronic component according to the present invention is not limited to a monolithic capacitor, but is generally a method for manufacturing a monolithic ceramic electronic component such as a monolithic inductor, a ceramic multi-layer substrate, or a monolithic piezoelectric component. Can be used.

[0029]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, the present invention will be clarified by describing embodiments with reference to the drawings. The following description of the embodiments is an example applied to a method of manufacturing a multilayer capacitor as a multilayer ceramic electronic component.

Example 1 As shown in FIG. 1, a support film 1 made of polyethylene terephthalate (hereinafter PET) was prepared. Next, Cu was vapor-deposited on the support film 1 to a thickness of 0.1 μm to form the first metal film 2. Further, the first metal film 2
Ni was vapor-deposited thereon to a thickness of 2 μm to form the second metal film 3.

Next, a photoresist is applied on the laminated metal film 4 composed of the first metal film 2 and the second metal film 3 formed as described above, and is etched by a known photolithographic method. The laminated metal film 4 was patterned by removing the remaining photoresist. FIG. 2 shows an internal electrode 4A made of a laminated metal film patterned in this way.

In the above etching, an aqueous ferric chloride solution was used as an etching solution. As a result of the above etching, the width of the first metal film 2 that is more easily etched than the second metal film 3 becomes narrower than that of the second metal film 3 as shown in an enlarged view in FIGS. 2 and 3. Was there. this is,
This is because the first metal film 2 was etched from the side by the action of the etching solution.

Next, from the side where the internal electrodes 4A formed by etching as described above are formed, on the supporting film 1, from the ceramic powder containing barium titanate as a main component, the organic binder and the organic solvent. The resulting ceramic slurry 5 was applied (see FIG. 4) to prepare a transfer metal film laminated ceramic sheet 6. In addition, 7 shows an unfired ceramic green sheet. The thickness of this ceramic green sheet 7 is 10 μm.

Next, a method for manufacturing a laminated ceramic capacitor using the transfer laminated ceramic sheet 6 obtained as described above will be explained. As shown in FIG. 5, first, the ceramic green sheet laminated body 12, which is supported on the supporting film 11 and has no electrodes, is placed on the laminating stage 10. The transfer metal film laminated ceramic sheet 6 obtained as described above was transferred onto the ceramic green sheet laminated body 12. That is, the transfer metal film laminated ceramic sheet 6 shown in FIG. 4 is superposed on the ceramic laminated body 12, pressed at a temperature of 80 ° C., and then the support film 1 is peeled off,
The transfer metal film laminated ceramic sheet 6 was transferred.

Further, the transfer of the transfer metal film multilayer ceramic sheet was continued so as to form a multilayer capacitor. In this case, two types of transfer metal film laminated ceramic sheets having different electrode positions were alternately laminated so that the internal electrodes constitute a laminated capacitor. In the above transfer,
The internal electrodes could be transferred without difficulty and without causing breakage on the ceramic green sheet.

Finally, the thickness 10 without electrodes is formed.
A 0 μm ceramic green sheet laminate was transferred, and the obtained laminate was pressed in the thickness direction. Thereafter, the mother laminated body thus obtained is cut in the thickness direction in order to cut it into individual laminated capacitor units, and 2 × 1.25 mm ×
A large number of raw chips of 1.25 mm were obtained. The obtained individual laminated body raw chips were fired in a reducing atmosphere to obtain a sintered body. A conductive paste serving as an external electrode was applied to predetermined regions on both end faces of the obtained sintered body, and the external electrode was formed by baking to obtain a multilayer capacitor.

FIG. 6 is a sectional view showing the multilayer capacitor obtained as described above. In FIG. 6, the multilayer capacitor 21 has internal electrodes 23 to 23 formed of the transfer metal film in the sintered body 22 obtained as described above.
Has 26. Further, external electrodes 27 and 28 are formed on both end surfaces of the sintered body 22.

Next, a plurality of types of transfer metal film supply bodies having different thicknesses of the first metal film and the second metal film were prepared, and the transferability thereof was evaluated. That is, when manufacturing the multilayer capacitor as described above using each transfer metal film supply body, it was confirmed by various transfer pressures whether or not the internal electrodes 4A were smoothly separated from the support film. The results are shown in Table 1.

[0039]

[Table 1]

As shown in Table 1, when the thickness ratio t ₁ / t _{2 of} the first and second metal films is 1/50, it is 20.
Transfer was possible at a transfer pressure of kgf / cm ² , but a part of the metal film for transfer remained on the support film side before the pressure bonding, and continuous transfer could not be performed.
When the ratio t ₁ / t ₂ is 1/5, 500k
Although transfer could be performed at a transfer pressure of gf / cm ² , it could not be peeled from the supporting film at a part of the laminated metal film portion, and continuous transfer could not be performed. On the other hand, when the ratio was 1/35 to 1/10, the laminated metal film could be satisfactorily transferred under the transfer pressure shown in Table 1.

Therefore, as is clear from the results shown in Table 1, by setting the ratio t ₁ / t ₂ within the range of 1/50 to 1/5, the internal electrode, which is a laminated metal film, can be selected if the transfer pressure is selected. 4A
It can be seen that can be transferred smoothly.

Example 2 The supporting film 1 used in Example 1 was prepared. On the support film 1, Ag is sputtered to a thickness of 0.1 μm to form a first metal film 2, and then Pd is sputtered thereon to a thickness of 1 μm to form a second metal film 3. Was formed. In the same manner as in Example 1 except that the laminated metal film 4 shown in FIG. 1 was formed in this way and an iron nitrate aqueous solution was used as the etching solution,
A metal film supply body for transfer was produced. A multilayer capacitor was manufactured in the same manner as in Example 1 using the obtained transfer metal film.

In Example 2, the first and second metal films 2 and 3 were formed so as to have the above-mentioned thickness.
When manufacturing a multilayer capacitor, the transfer metal film multilayer ceramic sheet has a ceramic green sheet thickness of 10 μm.
Despite being relatively thin as m, the ceramic green sheet could be peeled off smoothly from the support film without causing breakage.

[Brief description of drawings]

FIG. 1 is a partially cutaway cross-sectional view showing first and second metal films formed on a support film in an example.

FIG. 2 is a partial cutaway sectional view showing a transfer metal film obtained by etching a laminated metal film.

FIG. 3 is an enlarged cross-sectional view showing a main part of the transfer metal film supply body shown in FIG.

FIG. 4 is a partially cutaway cross-sectional view showing a process of forming a ceramic green sheet on a transfer metal film supply body.

FIG. 5 is a partial cutaway sectional view for explaining a process for manufacturing a multilayer capacitor.

FIG. 6 is a sectional view showing a multilayer capacitor.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Support film 2 ... 1st metal film 3 ... 2nd metal film 4 ... Laminated metal film 4A ... Transfer metal film 5 ... Ceramic slurry 6 ... Ceramic green sheet 7 ... Transfer metal film Laminated ceramic sheet

Claims (4)

[Claims] 1. A step of forming a first metal film made of a metal which is relatively easy to be etched on a support film by a thin film forming method, and a metal which is relatively hard to be etched on the first metal film. A transfer metal, which comprises a step of forming a second metal film made of, by a thin film forming method, to form a stacked metal film; and a step of patterning the stacked metal film by etching to obtain a transfer metal film supply body. Method for manufacturing membrane supply body. 2. When the thickness of the first metal film is t ₁ and the thickness of the second metal film is t ₂ , t ₁ / t ₂ is 1/5.
The method for producing a transfer metal film supply body according to claim 1, which is in a range of 0 to 1/5. 3. A step of forming a first metal film made of a metal which is relatively easily etched on the support film by a thin film forming method, and a metal which is relatively hard to be etched on the first metal film. Forming a second metal film by a thin film forming method to form a laminated metal film; and patterning the laminated metal film by etching to form an electrode pattern to obtain a transfer metal film supply body, A step of forming an unfired ceramic sheet on the transfer metal film supply body and forming a transfer metal film laminated ceramic sheet on a supporting film; and a step of forming the transfer metal film laminated ceramic sheet on another unfired ceramic Stacking on a sheet and peeling the supporting film to stack the metal film multilayer ceramic sheet for transfer, and repeating the stacking step. And a step of obtaining more laminate, the method of production of a multilayer ceramic electronic component. 4. When the thickness of the first metal film is t ₁ and the thickness of the second metal film is t ₂ , t ₁ / t ₂ is 1/5.
The method for manufacturing a monolithic ceramic electronic component according to claim 3, which is in the range of 0 to 1/5.