JP3316947B2 - Multilayer metal film support for electronic components, multilayer metal film laminated ceramic green sheet support and laminate - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a multilayer metal film support for an electronic component, which can supply, for example, a metal film used as an electrode in an electronic component by transfer.
In particular, the present invention relates to a multilayer metal film support for electronic components provided with a structure capable of controlling the peeling force of the multilayer metal film from the support with high accuracy.

[0002]

2. Description of the Related Art Conventionally, in a sintered body used for a ceramic laminated electronic component, an internal electrode pattern is formed by printing a metal paste on a ceramic green sheet, and then the ceramic green sheet on which the internal electrode is printed is formed. A method of firing the laminated body obtained by laminating, or a method of forming a ceramic green sheet on a lamination stage and obtaining a laminated body by repeating pattern printing of a conductive paste, and a method of firing the obtained laminated body Had been obtained.

In recent years, in ceramic laminated electronic parts,
Thinning and miniaturization are in progress. Accordingly, in the method of forming an internal electrode using a metal paste, the thickness of the metal paste at the time of application is larger than the thickness of the internal electrode after firing, that is, the dimensional change of the internal electrode before and after firing can be ignored. It is becoming difficult to obtain high-quality laminated electronic components. In addition, at the stage of obtaining the laminate before firing, the thickness of the portion where the internal electrode is formed and the portion where the internal electrode is not formed tend to vary, and the internal electrode is likely to be displaced.

Therefore, in order to reduce the dimensional change of the internal electrode before and after firing, particularly the change in thickness, a method of forming the internal electrode by a metal film formed by a thin film forming method instead of a metal paste to obtain a laminate. Has been proposed (JP-A-64-42809). In this method, a metal film formed by a thin-film forming method with a small thickness is used for an internal electrode before firing, which is formed by printing a metal paste. Therefore, it is possible to suppress a variation in thickness and a displacement of the internal electrodes in the laminate obtained before firing.

On the other hand, in order to reduce the size of the ceramic laminated electronic component, a laminate in which the thickness of the ceramic layer between the internal electrodes is reduced is required. Therefore, in recent years, instead of the conventional ceramic green sheet of about 20 μm,
A very thin ceramic green sheet having a thickness of not more than μm is used. Such a very thin ceramic green sheet has very low mechanical strength. Therefore, when the ceramic green sheet is formed on a support made of, for example, a synthetic resin film and then peeled from the support, or on a metal film (internal electrode) formed on the support, the above-described thin film is formed. When a molded ceramic green sheet (metal film laminated ceramic green sheet) is peeled from the support, the peeling force needs to be extremely small. In addition, a method of alternately transferring a ceramic green sheet supported by a support and a metal film supported by another support by a transfer method when obtaining a laminate, and laminating the same, has also been proposed. (JP-A-62-32909). Also in this method, since only the metal film needs to be peeled from the support, it is required to reduce the peeling force of the metal film from the support.

Therefore, conventionally, a release agent such as silicon has been applied on a support to form a release agent layer, and a metal film or a ceramic green sheet has been formed on the release agent layer. The above-mentioned peeling force means a force required to peel a metal film or a metal film-laminated ceramic green sheet laminated on the support directly or via a release agent layer from the support. Shall be.

[0007]

SUMMARY OF THE INVENTION In a multilayer capacitor,
There is a demand for further miniaturization and thinning, and thus the thickness of the ceramic layer between the internal electrodes has been further reduced to 5 μm or less at present. Also, other ceramic multilayer electronic components such as multilayer piezoelectric components are required to have a thinner ceramic layer between internal electrodes.

However, when an attempt is made to obtain a laminate having a very thin ceramic layer between the internal electrodes as described above, for example, the thickness of the ceramic layer between the internal electrodes is reduced to 5 μm.
When it is necessary to set the thickness of the ceramic green sheet or the ceramic green sheet on which the metal film for forming the internal electrode is formed,
Must be: For this reason, the peeling force of the ceramic green sheet or the metal film-laminated ceramic green sheet from the support must be smaller than in the past.

However, the smaller the peeling force is, the better. That is, in the step of forming the metal film and the step of forming the ceramic green sheet, the metal film and the ceramic green sheet are reliably formed or formed on the support, or the metal film is formed on the support. When a ceramic green sheet is subsequently formed thereon, it is necessary that the lower metal film is securely held on the support.

That is, although the peeling force of the metal film or the ceramic green sheet to the support is required to be reduced as the thickness of the ceramic green sheet is reduced, it is controlled with high precision so as to have an appropriate peeling force. There must be. However, as before,
With the method in which the release agent layer is simply provided on the support surface, the peeling force of the metal film or the ceramic green sheet on the support cannot be controlled with high accuracy.

An object of the present invention is to provide a multi-layer metal film support for an electronic component and a multi-layer metal having a structure capable of controlling the peeling force of a metal film or a metal film-laminated ceramic green sheet formed on the support with high precision. It is an object of the present invention to provide a film laminated ceramic green sheet support.

[0012]

According to the first aspect of the present invention, a support, a thin film formed on the support by a thin film forming method, and an opening area ratio of a pinhole is 30 to 5 mm.
An electron, comprising: a first metal film in which a plurality of pinholes are formed so as to be 0%; and a second metal film formed by plating on the first metal film layer. It is a multilayer metal film support for components.

According to a second aspect of the present invention, there is provided a multi-layer ceramic green sheet having a multi-layered ceramic green sheet laminated on a support so as to cover the multi-layer metal film. 2. A multilayer ceramic green sheet support comprising a ceramic green sheet laminated directly or indirectly on the second metal film.

Further, the invention according to claim 3 is a laminate obtained by laminating a ceramic green sheet on which an internal electrode is formed and a ceramic green sheet on which an internal electrode is not formed, A ceramic green sheet on which the internal electrodes are formed is a laminate formed by transferring the ceramic green sheet from the multilayer metal film-laminated ceramic green sheet support according to claim 2.

[0015] In the first aspect of the present invention, the pinhole means a through hole formed in the first metal film, and the plurality of pinholes are formed in the first metal film. However, the plane shape of this pinhole is not particularly limited, and it can be formed to have various plane shapes such as a circle, an ellipse, and other irregular shapes, and a plurality of pinholes have the same shape. No need to have.

Further, the size of the pinhole is not particularly limited, but is usually about 0.5 to 3 μm. In the first aspect, the plurality of pinholes are formed in the first metal film, and the second metal film is formed on the first metal film by a plating method. Therefore,
In the portion where the pinhole is formed, the first
Is not attached to the support. Further, since the second metal film is formed by plating, it should not adhere to the exposed portion of the support in the pinhole. However, since the pinhole is relatively small and adheres to the side surface of the portion of the first metal film facing the pinhole, the pinhole is formed as a result. Therefore, in the pinhole portion, the second metal film adheres to the surface of the support.

Therefore, since the bonding force between the multilayer metal film and the support is different between the pinhole portion and the other portions, the support of the multilayer metal film is adjusted by adjusting the opening area ratio of the pinhole. The peeling force from the can be adjusted.

The open area ratio of the pinhole A, to indicate the sum of all the areas of the plurality of pinholes, the ratio of the area of the main surface of the first metal film.

The first metal film is preferably formed by a thin film forming method such as vapor deposition, sputtering or ion plating, whereby an electrode having high dimensional stability can be formed. Further, the second metal film layer is formed on the first metal film by the plating method as described above. The plating method may be any one of electroplating and electroless plating. Alternatively, one or more metal film layers may be similarly formed on the second metal film layer by a plating method.

The support is made of a suitable material other than a metal. For example, a synthetic resin film such as polyethylene terephthalate or polypropylene is used.

The materials forming the first and second metal films include various metals used as electrode materials in electronic parts, for example, Ag, Pd, Cu, Ni, Pt.
Alternatively, an alloy thereof is used.

[0022]

According to the first aspect of the present invention, a plurality of pinholes are formed in the first metal film layer so as to have the specific pinhole opening area ratio.
A second metal film is formed on the metal film by a plating method. Therefore, in the portion where a plurality of pinholes are formed, the second support is only relatively weakly joined to the support, so that the pinhole opening area ratio is adjusted within the specific range. By doing so, the peeling force of the multilayer metal film on the support can be controlled with high precision.

According to the second aspect of the present invention, since the ceramic green sheet is laminated directly or indirectly on the second metal film, the peeling force of the metal film laminated ceramic green sheet from the support is increased. Can be controlled with high precision in the same manner as in the first aspect of the present invention.

Therefore, using the invention of claim 2,
The multi-layer metal film-laminated ceramic green sheet can be easily transferred and laminated from the support by the transfer method, so that a small-sized internal electrode formed of the multi-layer metal film is formed as in the invention according to claim 3. A ceramic laminate can be obtained stably. Furthermore, firing this laminate,
By using the obtained sintered body, a ceramic multilayer electronic component such as a multilayer capacitor can be obtained. Therefore, according to the third aspect of the present invention, the thickness of the ceramic green sheet can be further reduced as compared with the conventional method, so that a smaller and thinner ceramic laminated electronic component can be provided.

[0025]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, the present invention will be clarified by describing non-limiting embodiments of the present invention.

EXPERIMENTAL EXAMPLE 1 (Example 1) First, a support made of a polyethylene terephthalate film which does not deform at a temperature of about 100 ° C. was prepared, and one surface of the support was coated with a silicone resin and subjected to a mold release treatment. Was.

Next, as shown in FIG. 1, a vapor deposition film made of silver having a pinhole opening area ratio of 30%, a pinhole diameter of 1 μm, and a thickness of 0.1 μm is formed on the support 1 to form a first metal film. And 2. The formation of the plurality of pinholes A is performed by depositing silver on the entire upper surface of the support 1, coating the photoresist on the silver deposition film, exposing and developing, and forming openings in the photoresist at necessary pinhole portions. Formed and nitric acid second
The silver deposition film was etched with an aqueous iron solution, and then the resist was removed to form the film.

Next, as shown in FIG. 2, a second metal film 3 made of palladium was formed by electroplating on the first metal film 2 on which the pinholes A were formed as described above. The current density at the time of electroplating is 1 A / dm.
^The plating bath was an ammine complex plating bath, and plating was performed using the first metal film 2 made of a silver vapor-deposited film as a cathode and a platinum plate as an anode. As above, thickness 0.5μ
m of the second metal film 3 was formed, and a multilayer metal film support of Example 1 shown in FIG. 2 was obtained.

As is clear from FIG. 2, the diameter of the pinhole A is as small as 1 μm, and the second metal film 3 is formed by plating.
Are also in close contact with the side surface of the first metal film 2 facing the pinhole A, and as a result, have penetrated into the pinhole A. Example 2 Example 1 except that the second metal film was formed by plating silver by electroplating.
In the same manner as in the above, a multilayer metal film support of Example 2 was obtained. The conditions for plating the second metal film were such that the current density was 1 A / dm ² , the plating bath was a cyan bath, the first metal film was a cathode, and a silver plate was an anode. The thickness of the second metal film formed as described above by plating silver was 0.5 μm. (Example 3) A multilayer metal film support of Example 3 was obtained in the same manner as in Example 2 except that the pinhole opening area ratio of the first metal film of Example 2 was changed to 50%. . (Embodiment 4) As shown in FIG. 3, a first metal film 2 having a pinhole A having a pinhole opening area ratio of 30% and a pinhole diameter of 1 μm is formed on a support 1 in the same manner as in Embodiment 1. Formed. Next, the second metal film 3 having a thickness of 0.5 μm is formed by plating silver on the first metal film 2 in the same manner as in the second embodiment, and further, palladium is electroplated thereon. As a result, a third metal film 4 having a thickness of 0.25 μm was formed. Thus, a multilayer metal film support of Example 4 was obtained. (Comparative Example 1) A first metal film was formed by vapor-depositing silver on the entire surface of a support in the same manner as in Example 1 except that no pinhole was formed, and then the first metal film was formed. Palladium was electroplated on the membrane in the same manner as in Example 1,
A second metal film was formed, and a multilayer metal film support of Comparative Example 1 was obtained.

In order to evaluate the transferability of each of the multilayer metal film supports of Examples 1 to 4 and Comparative Example 1, the multilayer metal film was transferred to each of paper and plastic substrates.

First, with respect to each of the multilayer metal film supports of Examples 1 to 4 and Comparative Example 1, an adhesive was coated on the surface of the multilayer metal film, and then the substrate made of paper and plastic was hot-stamped. The multilayer metal film was transferred. The hot stamping treatment is 100 kg / c
A pressure of m ² was applied for 10 seconds, and hot stamping was performed at each of 50 ° C., 60 ° C., 70 ° C., and 80 ° C.

The results are shown in Table 1.

[0033]

[Table 1]

The meanings of the evaluation symbols in Table 1 are as follows. …: Transfer was successfully performed. X: Not transferred.

As described above, in Examples 1 to 4, it is found that the transferability of the multilayer metal thin film can be controlled by controlling the pinhole opening area ratio of the first metal film. In addition,
In Examples 1 to 4, a metal film formed by depositing silver was used as the first metal film. Alternatively, when copper, nickel, gold, or the like was used, a pinhole was formed in the same manner as described above. It was confirmed that the transferability of the metal thin film could be controlled by controlling the opening area ratio.

Experimental Example 2 (Example 5) A pin-hole-free copper vapor-deposited film having a thickness of 0.1 μm was formed on a support made of a polyethylene terephthalate film by vapor deposition. The conditions for the vapor deposition were the same as in the case of the silver vapor deposition film of Example 1 in Experimental Example 1. Next, a pinhole opening area ratio of 30% was applied to the copper vapor-deposited film by using the photolithography technique as in the first embodiment.
A plurality of pinholes were formed so as to have a pinhole diameter of 1 μm, and a first metal film was formed. Further, as shown in FIG. 4, nickel was electroplated as a second metal film 13 on the first metal film 12 to form a nickel film having a thickness of 1 μm. This electroplating has a current density of 1 A / dm.
² , using a sulfamic acid bath as the plating bath,
The metal film 12 was used as a cathode and a nickel plate was used as an anode. Comparative Example 2 A multilayer metal film support of Comparative Example 2 was obtained in the same manner as in Example 5, except that no pinhole was formed in the first metal film formed first in Example 5.

The following experiment was performed to evaluate the transferability of the multilayer metal film supports of Example 5 and Comparative Example 2 obtained as described above. A non-reducing dielectric ceramic slurry containing barium titanate as a main component was coated on the surface of the multilayer metal film and dried to form a ceramic green sheet 14 shown in FIG. In Comparative Example 2, a ceramic green sheet was similarly formed on the second metal film.

Next, the ceramic green sheet laminated with the multilayer metal film was peeled from the support 1, and the peeling force was evaluated. In Comparative Example 2, the multilayer metal film did not peel at all from the support 1 even though the ceramic green sheet was peeled from the multilayer metal film. In contrast, Example 5
Then, with the peeling of the ceramic green sheet 14,
The multilayer metal film was also smoothly separated from the support 11.

Experimental Example 3 After the second metal film 13 was formed in Example 5, the multilayer metal film was processed by photolithography so as to have the shape of the internal electrode of the multilayer capacitor. That is, the photoresist according to the shape of the internal electrode is patterned, the multilayer metal film is etched with an aqueous ferric chloride solution, and then the photoresist is removed to form a metal pattern for the internal electrode using the multilayer metal film. did. Next, after the above-described patterning, a ceramic green sheet was formed on the surface of the support 1 on which the multilayer metal film was formed, using a ceramic slurry containing a non-reducing dielectric ceramic as a main component by a doctor blade method. Thereafter, thermocompression bonding is performed from the ceramic green sheet side onto the lamination stage, and then the support is peeled off. Subsequently, a new multilayer metal film laminated ceramic green sheet support is thermocompression bonded from the ceramic green sheet side, and the support is pressed. By repeating the step of peeling, a laminate was obtained. In this case, the multilayer metal film did not remain on the support side when the support was peeled off after each thermocompression bonding. That is, it was smoothly separated from the support together with the ceramic green sheet, and was transferred to the laminate.

The laminated body obtained as described above is cut in the thickness direction so as to form a single laminated capacitor, fired, and external electrodes are formed on both end surfaces of the obtained sintered body. A multilayer capacitor was manufactured.

In the obtained multilayer capacitor, the thickness of the internal electrodes is smaller than that of a conventional multilayer capacitor in which a metal paste is formed by screen printing, and the thickness of the internal electrodes is more uniform in the direction in which the ceramic green sheets extend. there were. Further, since there were no defects such as pores in the internal electrodes, no deterioration in electrical characteristics such as a decrease in capacitance was observed.

Experimental Example 4 (Example 6) First, as shown in FIG. 5, a support 21 made of the same material as the support 1 used in Example 1 was prepared. Next, copper was deposited on the support 21 to form a 0.1 μm-thick copper deposited film having no pinhole. The conditions for this vapor deposition were the same as in the case of forming the silver vapor deposition film in Experimental Example 1.

An evaporated film made of copper was used in Example 1 of Experimental Example 1.
Similarly to the above, a plurality of pinholes having a pinhole opening area ratio of 30% and a pinhole diameter of 1 μm were formed by using the photolithography technique, and the first metal film 22 was formed. next,
Nickel was plated on the first metal film 22 by electroless plating to form a second metal film 23. The electroless plating is performed at a temperature of 50 ° C. using a zinc hypophosphite reduction bath,
A 1 μm thick nickel plating film was obtained. (Example 7) The multilayer metal film of Example 7 was formed in the same manner as in Example 6, except that the second metal film 23 was formed by plating nickel to a thickness of 1 µm by electroplating. A support was obtained. The electroplating conditions were the same as in Example 1 of Experimental Example 2. Comparative Example 3 A multilayer metal film support of Comparative Example 3 was obtained in the same manner as in Example 6, except that no pinhole was formed in the first metal film.

The transferability of each of the multilayer metal film supports of Examples 6, 7 and Comparative Example 3 obtained as described above was evaluated. The evaluation method was the same as in Experimental Example 1. That is, a transfer test was performed by hot stamping. The results are shown in Table 2 below.

[0045]

[Table 2]

The meanings of the evaluation symbols in Table 2 are as follows. …: Transfer was successfully performed. X: Not transferred.

In the sixth embodiment, the second metal film 23 is formed at the pinhole portion of the first metal film 22 made of a copper vapor deposition film.
Is directly bonded to the support 21, and the peeling force of the multilayer metal film becomes a bonding force between the second metal film and the support 21. In a portion where the pinhole does not exist in the copper vapor deposition film, the peeling force of the metal film becomes a bonding force between the copper vapor deposition film and the support 21. Therefore, the total peeling force is the sum of the peeling force at the pinhole portion and the peeling force at the portion without the pinhole. Therefore, the peeling force can be adjusted by forming the pinhole to have a certain opening area ratio as described above by the difference in the peeling force between the portion where the pinhole exists and the portion where the pinhole does not exist. .

In each of the embodiments described above, the formation of the pinhole in the first metal film uses a photoresist,
Performed by using photolithography technology, for example, partially activating the support surface, forming a portion that can be electrolessly plated on the support surface and a portion that cannot be electrolessly plated, thereby making the electroless plating impossible The first metal film may be formed by an electroless plating method so that a pinhole is formed in an appropriate portion, or a mask is placed on the surface of the support, and the portion covered with the mask becomes a pinhole. As described above, a pinhole may be formed by evaporating metal.

[Brief description of the drawings]

FIG. 1 is an exploded perspective view illustrating a structure of a first metal film and a support in an embodiment.

FIG. 2 is a partially cutaway sectional view showing the structure of the multilayer metal film support of Example 1.

FIG. 3 is a partially cutaway sectional view showing a multilayer metal film support of Example 4.

FIG. 4 is a partially cutaway sectional view showing a multilayer metal film-laminated ceramic green sheet support of Example 5.

FIG. 5 is a partially cutaway sectional view showing a multilayer metal film support of Example 6.

[Explanation of symbols]

 1,21 ... Support 2,12,22 ... First metal film 3,13,23 ... Second metal film 14 ... Ceramic green sheet A ... Pinhole

Continuation of front page (58) Field surveyed (Int.Cl. ⁷ , DB name) H01G 4/00-4/42

Claims (3)

(57) [Claims] 1. A support and, first of the on the support is formed by a thin film forming method, and a plurality of pin holes so that the opening area ratio of the pinhole is 30 to 50% is formed And a second metal film formed by plating on the first metal film. A multilayer metal film support for electronic components, comprising: 2. A multilayer ceramic green sheet support further comprising a ceramic green sheet directly or indirectly laminated on the second metal film. 3. A laminated body obtained by laminating a ceramic green sheet on which an internal electrode is formed and a ceramic green sheet on which an internal electrode is not formed, wherein the ceramic green sheet has the internal electrode formed thereon. A laminate, wherein the sheet is formed by transferring the multilayer metal film-laminated ceramic green sheet from the multilayer metal film-laminated ceramic green sheet support according to claim 2.