JPH05132758A - Manufacture of metallic thin film excellent in transferrability - Google Patents

Abstract

PURPOSE:To manufacture a metallic thin film excellent in transferrability by forming a metallic thin film on a film in a state in which oxygen partial pressure or steam partial pressure is specified. CONSTITUTION:In a state in which oxygen partial pressure or steam partial pressure is controlled to 2X10<-4> to 2X10<-3>Torr, a metallic thin film 2 (such as Ni, Cu and Ag) is formed on a film 1 (such as polyethylene phthalate) by vapor deposition. At this time, as for the vapor deposition, any of resistance heating vapor deposition, induction heating vapor deposition and electron beam vapor deposition may be executed. In this way, the metallic thin film 2 excellent in transferrability can be obtd.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for producing a metal thin film having excellent transferability. The metal thin film obtained by the present invention can be formed into a circuit on a substrate, an electrode of an electronic component, or a metal foil for display by transferring.

[0002]

2. Description of the Related Art Conventionally, a technique of transferring a metal thin film formed on a film onto an object, such as a metal thin film for hot stamping, has been used. When the metal thin film is formed on the film for the purpose of transfer, it is naturally necessary to form the metal thin film which is easily peeled off.

As described above, in order to facilitate the peeling of the metal thin film on the film, an underlayer which is destroyed by a method such as heating is usually formed on the film,
On this, a metal thin film is formed by a method such as vapor deposition or sputtering. After forming the metal film, the film is heated with the metal film to destroy the underlying layer between the film and the metal film, thereby peeling the metal film from the film for transfer. The underlayer may be destroyed by radiation as well as being destroyed by heating as described above.

[0004]

As described above, according to the method capable of transferring the metal thin film formed on the underlayer, which is scheduled to be destroyed, is formed on the film. In addition to the metal thin film, a part of the destroyed underlayer is transferred onto the object. For example,
When the metal thin film is used for decoration or the like, there is almost no problem as long as the underlayer is transparent and the transferred amount of the underlayer is very small.

However, as described in Japanese Patent Application Laid-Open No. 1-42809, the transfer technique as described above is applied to the formation of electrodes of electronic parts, more specifically the internal electrodes of laminated ceramic capacitors. In case of 0.1
This method is unsuitable because impurities of less than 5% may cause a problem.

The film may be subjected to a surface treatment so that the sheet formed on the film can be easily peeled off. However, currently established techniques are only surface treatment techniques that are effective only for resin-based sheets, and there is no effective surface treatment technique when peeling a metal thin film formed by a method such as vapor deposition or sputtering.

Therefore, an object of the present invention is to provide a method for producing a metal thin film having excellent transferability without relying on the underlayer which is scheduled to be destroyed, that is, a metal thin film having excellent transferability on the film. Is to provide a way to form.

[0008]

The method for producing a metal thin film having excellent transferability according to the present invention is a vapor deposition method in which oxygen partial pressure or water vapor partial pressure is adjusted to 2 × 10 ⁻⁴ to 2 × 10 ⁻³ Torr. Is characterized in that a metal thin film is formed on the film.

The above-mentioned vapor deposition may be performed by any of the resistance heating vapor deposition method, the induction heating vapor deposition method, and the electron beam vapor deposition method. A method of accelerating vaporized atoms such as sputtering is excluded.

The metal thin film obtained by the present invention is, for example, a thin film of nickel, copper, silver or the like. The film used for forming the metal thin film is, for example, a resin film such as polyethylene terephthalate.

Objects to which the metal thin film obtained by the present invention is transferred include ceramic green sheets, ceramics, resins and metals. In the transfer, the metal thin film is kept in contact with an object and hot stamping is performed, for example, at a pressure of 10 to 500 kg / c.
m < ² >, temperature 60-95 degreeC is implemented in the range.

[0012]

According to the present invention, when water is present at the interface between the metal thin film and the film, the adhesive force between the two becomes small, and when the resin is adhered onto the metal, if the metal surface is oxidized, It is based on the finding that the adhesive strength of is reduced.

Conventionally, for example, in the field of the semiconductor industry, when a metal thin film is formed on a substrate by vapor deposition or sputtering, the substrate is exposed to plasma in order to enhance the adhesive force between the substrate and the metal thin film. The removal of adhering gas molecules on the substrate surface is performed. On the other hand, in the present invention, since a predetermined gas is introduced into the vapor deposition apparatus, the number of attached gas molecules on the substrate surface is increased, and as a result, the adhesive force between the substrate and the metal thin film is weakened. Presumed.

It is also considered that since the metal is evaporated in an atmosphere having a high oxygen partial pressure or water vapor partial pressure, the properties of the metal thin film are changed and the adhesive force between the metal thin film and the film is reduced. ..

[0015]

As described above, according to the present invention, when the metal thin film is formed on the film by vapor deposition, the oxygen partial pressure or the water vapor partial pressure in the vapor deposition apparatus is 2 × 10 ⁻⁴ to 2 × 10.
By setting the pressure to be ^-3 Torr, a metal thin film having excellent transferability can be obtained.

The metal thin film obtained according to the present invention does not have a ground layer between the conventional metal thin film for hot stamping and the film, which is scheduled to be broken, so that even a trace amount of impurities such as electronic parts poses a problem. Even for applications that become
It can be used without problems.

Further, since the metal thin film on the film can be easily patterned by, for example, a photoetching method, the metal thin film obtained by the present invention can be used as an electrode for electronic parts, an internal electrode of a multilayer substrate, or an external conductor. ,
It can be advantageously used as a conductor on a circuit board, a metal foil for display, and the like.

[0018]

EXAMPLE The following experiment was conducted according to the present invention. Experimental Example 1 As shown in FIG. 1, first, a film 1 was prepared. As the film 1, a film made of polyethylene terephthalate which does not change at a temperature of about 100 ° C. was used, and such a film 1 was silicone-coated in order to further enhance the transferability of the metal thin film to be formed later.

Next, a Cu vapor deposition film 2 was formed on the film 1 as shown in FIG. To form the Cu vapor deposition film 2, a resistance heating vapor deposition method with a heating current of 500 A (Comparative Example 1-
1), an induction heating vapor deposition method with an output of 10 kW (Comparative Example 1-2).
And an electron beam evaporation method with an output of 10 kW (Comparative Example 1-
Three methods of 3) were used. The atmosphere during vapor deposition was not particularly controlled, and the atmosphere was kept evacuated to 5 × 10 ⁻⁴ Torr. The components of the residual gas are nitrogen, oxygen, and water, and the respective pressures are 2 × 10 ⁻⁴ ,
It was 0.5 × 10 ⁻⁴ and 2.5 × 10 ⁻⁴ Torr. The thickness of the obtained Cu vapor deposition film 2 was 0.3 μm.

On the other hand, during vapor deposition, once at a pressure of 5 × 10 ⁻⁵ from the atmosphere.
After evacuation to Torr, oxygen gas was introduced into the vapor deposition apparatus, and the degree of vacuum was adjusted to 5 × 10 ⁻⁴ Torr, in the same manner as in the comparative example, the Cu vapor deposition film 2 was formed on the film 1.
Formed. A heating current of 5 is applied to the formation of the Cu vapor deposition film 2.
00A resistance heating evaporation method (Example 1-1), output 10k
Induction heating evaporation method of W (Example 1-2) and output 10 k
The electron beam evaporation method of W (Example 1-3) was used. The components of the residual gas were nitrogen, oxygen, and water, and the respective pressures were 0.2 × 10 ⁻⁴ , 4.5 × 10 ⁻⁴ , and 0.3 × 10 ⁻⁴ Torr. The thickness of the obtained Cu vapor deposition film 2 was 0.3 μm.

In order to evaluate these Comparative Examples 1-1, 2, 3 and Examples 1-1, 2, 3, the following experiment was conducted.

Two 2 cm square plates were prepared, each of these comparative examples and examples was sandwiched between two plates, and each of the comparative examples and examples and the plate were bonded at their respective contact surfaces with an adhesive. Fixed by. In this state, the plate was pulled outward to examine the force required for peeling the Cu vapor deposition film 2 from the film 1, and the results shown in Table 1 were obtained. In Table 1, the unit of the number showing the peeling force is "g"
Is.

[0023]

[Table 1]

As described above, the peelability of the Cu vapor deposition film 2 was improved by introducing oxygen gas during vapor deposition. Experimental Example 2 Instead of the oxygen gas used when carrying out Examples 1-1, 2 and 3 in Experimental Example 1, water vapor was used and introduced into the vapor deposition apparatus. That is, during vapor deposition, once 5
After evacuation to × 10 ^-5 Torr, water vapor was introduced into the vapor deposition apparatus and Cu was formed on the film 1 in an atmosphere in which the degree of vacuum was adjusted to 5 × 10 ^-4 Torr, as shown in FIG.
The vapor deposition film 2 was formed. To form the Cu vapor deposition film 2, a resistance heating vapor deposition method with a heating current of 500 A (Example 2-1), an induction heating vapor deposition method with an output of 10 kW (Example 2-2) and an electron beam vapor deposition method with an output of 10 kW (implementation). Example 2-3) was used. The components of the residual gas are nitrogen, oxygen, and water,
Each pressure is 0.2 × 10 ^-4 , 0.05 × 1
It was 0 ⁻⁴ , and 4.3 × 10 ⁻⁴ Torr. The thickness of the obtained Cu vapor deposition film 2 was 0.3 μm.

Experimental example 2-1 thus obtained
2 and 3 were evaluated in the same manner as in Experimental Example 1, and the results shown in Table 2 below were obtained.

[0026]

[Table 2]

As described above, the peelability of the Cu vapor deposition film 2 was also improved by introducing water vapor during vapor deposition.

As described above, according to the present invention, as a metal thin film, Cu
Although the case of obtaining a vapor-deposited film has been described, the type of metal thin film to be vapor-deposited is arbitrary.

The film for forming the metal thin film was coated with silicone in the above-mentioned experimental example to improve transferability, but such surface treatment is not essential in the present invention. .. If a material that originally has a low adhesion to a metal is used as a material for forming the film itself, it is not necessary to perform a surface treatment to improve transferability.

[Brief description of drawings]

FIG. 1 is a cross-sectional view showing a Cu vapor deposition film 2 formed on a film 1 according to an experimental example carried out according to the present invention.

[Explanation of symbols]

 1 film 2 Cu vapor deposition film (metal thin film)

Claims (1)

[Claims] 1. A partial pressure of oxygen or water vapor is set to 2 × 10 ^−4.
A method for producing a metal thin film having excellent transferability, which comprises forming a metal thin film on a film by vapor deposition in a state of being adjusted to 2 × 10 ⁻³ Torr.