JP2003033994A - Metallized film and metal foil - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a metallized film and a metal foil which are suitable for production of extremely thin metal foil capable of producing a fine pattern to be utilized in a build-up multilayer wiring board or a PDP electromagnetic shielding member or the like. SOLUTION: The film with metal foil to be easily peeled from a film is produced by forming a release layer on the film to serve as a base material, depositing metal on the release layer by vapor-deposition or the like, and growing the vapor-deposition metal into a metal film by the electrolytic plating method.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a metallized film suitable for use in the production of ultra-thin metal foils for fine patterns used in build-up multilayer wiring boards, PDP electromagnetic wave shielding materials, etc. The present invention relates to a metal foil to be peeled off.

[0002]

2. Description of the Related Art Generally, as a method for producing a metal foil, a method called a rolling method for heating a metal plate and molding it through a narrow roll gap to obtain a metal foil, and Patent Document 2001.
There is known a method of electroplating, which is proposed in Japanese Patent No. 81592, in which a metal drum is plated with metal and the plating is removed to obtain a metal foil.

However, when producing an ultra-thin metal foil, it is usually difficult to produce a metal foil having a thickness of 18 μm or less by the rolling method because the thickness accuracy becomes strict and the mechanical strength becomes weak. It is common to be done.

On the other hand, a metal foil used for a build-up multilayer wiring board, a PDP electromagnetic wave shield material, etc. is usually subjected to an extremely fine processing of several tens to several μm called fine pattern processing. The thickness of the foil is required to be 10 μm or less.

However, for example, a copper foil generally used for wiring of a multilayer wiring board has a thickness of 1 by the electrolytic method.
Although it is possible to produce ultra-thin foils of 0 μm or less, the lower limit of the thickness that can be produced as a single copper foil is 9 μm because the mechanical strength of the copper foil itself decreases, and 3 μm is the lower limit even with a carrier. The situation.

Further, in the case of a copper foil having a thickness of 3 μm, it is common to use a copper foil having a thickness of 35 μm as a carrier.
After the m-thick foil is peeled off, the copper foil of 35 μm as a carrier material is discarded, so more copper material is used than necessary, and it becomes inevitably expensive.

[0007]

Therefore, in view of the above problems, the object of the present invention is preferably a multilayer wiring board or a PDP.
It is an object of the present invention to provide a metallized film for fine pattern processing, which is used as an electromagnetic wave shielding material, for obtaining an ultrathin copper foil having a thickness of less than 3 μm.

Another object of the present invention is to provide a metal foil obtained by peeling a metal layer from the metallized film, particularly preferably an ultrathin metal foil for fine patterns.

[0009]

The metallized film of the present invention for solving the above-mentioned problems has a thickness of 0.1 mm or less on a release layer of a base film having a release layer on one side or both sides. Three
Adhesion between 1 μm and 3 μm is 1 g / cm to 100 g / cm
Is a metallized film provided with the metal layer.

Further, in the metallized film of the present invention,
The release layer of the substrate film preferably contains any one of urea resin, silicone resin, cellulose resin, acrylic resin or wax, and the metal layer further comprises AL, gold,
It is preferable that the conductive material contains silver, copper, nickel, or chromium alone or an alloy, and has electrical conductivity.

In the metallized film of the present invention, a vapor-deposited metal film is provided by vapor deposition on a release layer of a base film having a release layer, and the metal film is grown by a plating method to form a metal layer. It can be manufactured.

Further, the metal layer constituting the metallized film can be easily peeled off from the metallized film, and it is possible to use only the metal foil.

[0013]

BEST MODE FOR CARRYING OUT THE INVENTION The metallized film of the present invention comprises a release layer of a base film having a release layer on one side or both sides,
Peel strength of 1 g / cm to 100 with a thickness of 0.3 μm to 8 μm
A metal layer of g / cm is provided.

The metallized film of the present invention will be described in detail below with reference to the drawings.

FIG. 1 is a schematic side view for explaining a conventional electrolytic foil production process generally called an electrolysis method. In FIG. 1, an electrode roll called an electrolysis drum (1) is used as a cathode, and the electrolysis drum (1) is immersed in an electrolysis solution (2) in which a metal to be plated is dissolved.
The electrolytic solution container (3) containing is used as an anode. By passing an electric current through the electrolytic solution between the electrolytic drum (1) and the electrolytic solution container (3), a metal film is deposited on the electrolytic drum (1). The metal foil deposited on the electrolytic drum (1) is peeled off from the electrolytic drum (1), washed with a washing layer (4) and then wound on the drum. Also,
In the case of copper foil or the like, if necessary, rust prevention treatment may be applied after washing with water to prevent oxidation.

In FIG. 1, the body surface of the electrolytic drum (1) must be made of a conductive metal. Further, since the surface of the finished metal foil in contact with the body surface has substantially the same roughness as the body surface, the body surface of the electrolytic drum (1) is generally mirror-finished. Furthermore, if the end surface of the electrolytic drum (1) is a non-conductive material and has not been insulated, a breakage may occur when the metal deposited on the body surface of the electrolytic drum (1) is peeled off.

Although the electrolytic plating method is used here as the plating method for depositing the metal on the body surface of the electrolytic drum (1), it is also possible to use the electroless plating method.

In the conventional method, for example, when a copper foil having a thickness of less than 9 μm is produced, the absolute strength of the copper foil is removed when the copper foil is peeled off from the body surface of the electrolytic drum (1). 2a, the copper foil is torn, so as shown in Figure 2a,
A copper foil (5) for carrier prepared in advance is held in the electrolytic drum (1) and deposited on the copper foil for carrier.
It is washed with water and wound up as it is, and after being processed by the end user as desired, it is peeled off from the carrier copper foil. Figure 2
2A is a schematic side view for explaining a conventional electrolytic foil production apparatus using a carrier foil, and FIG. 2B is a cross-sectional view showing the configuration of an electrolytic foil produced using the production apparatus of FIG. 2A. is there.

FIG. 4 is a cross-sectional view illustrating the structure of the metallized film of the present invention. In FIG. 4, a release film (7) is previously provided on a plastic film (6) which is a base material by a coating treatment or the like to form a base film, and metal is vapor-deposited on the release layer (7) to form a base film. After the surface is covered with a vapor-deposited metal film (8), a metal coating (9) is grown by a plating method to obtain a metallized film having a metal layer (10) with a thickness of 0.3 μm to 8 μm.

The plastic film (1) constituting the base material film used in the present invention is not particularly limited, but it is particularly low in cost and has good acid resistance and alkali resistance. A plastic film made of a polyolefin film such as a polypropylene film is suitable.
The thickness of the plastic film (1) varies depending on the material, but is preferably 5 to 100 μm. Particularly, for a polyester film or the like, 12 to 75 μm is suitable.

In the present invention, the release layer (2) is formed on one side or both sides of the base film. As the release layer (2), a silicon-based release layer or a fluorine-based release layer is usually used. However, the material is not particularly limited, and a metal can be vapor-deposited on the release layer. Good. In the present invention, as the release layer (2), a coating agent containing any one of urea resin, silicone resin, cellulose resin, acrylic resin or wax can be applied, and the thickness of the metal foil (metal layer) or It is also possible to use properly depending on the material. The release layer (2) can be preferably formed by coating on the plastic film (1). The thickness of the release layer (2) is preferably 0.
It is about 0.1 to 3 μm.

In the present invention, a metal layer is formed on the release layer (7). In the present invention, the metal layer can be formed by growing a metal film (8) formed by vapor deposition by a plating method or the like.

The material of the metal layer is not particularly limited as long as it is a metal that can be vapor-deposited and is usually used as an electrode. For example, aluminum, zinc, gold,
A single metal or alloy metal such as silver, copper, nickel and chromium is preferable.

In the present invention, the thickness of the metal layer (8) is
0.3 μm to 8 for fine patterning
It is important to be in the μm range. In particular, from the viewpoint of improving the pattern accuracy in recent years, it is preferably 0.3 to 4 μm.

In the metallized film of the present invention, the adhesion of the metal layer formed on the release layer (7) is
It is important to be 1 g / cm to 100 g / cm.
When the adhesive strength is 1 g / cm or less, the metal foil on the film is easily peeled off when patterned, and it is difficult to handle, and when it is 100 g / cm or more, the absolute strength of the ultrathin metal foil is insufficient. When the metal foil is peeled off, the metal foil breaks.

The metal film in the present invention is formed by depositing a metal layer of 500 to 3000 angstroms on the film by a general vacuum deposition method such as a high frequency heating method, a resistance heating method, an EB heating method, a sputtering method, or an ion plating method. It can be grown to the required thickness by the electrolytic plating method.

In the present invention, the metal layer is not limited to a single layer, and a plurality of metals may be stacked for the purpose of anticorrosion, etc.
As the anticorrosion layer, it is possible to provide an inorganic film such as Au, Cr or SiO _x, or an organic film such as polysiloxane, silazane or a fluorine compound.

The metal layer can be peeled off from the metallized film of the present invention to obtain a metal foil. The metal foil can be preferably used for manufacturing a build-up multilayer wiring board, a PDP electromagnetic wave shield material, or an ultrathin metal foil for fine patterns used for electrodes of small electronic components.

[0029]

Example 1 A biaxially stretched polyethylene terephthalate film having a thickness of 50 μm was coated with a melanin resin to a thickness of 0.1 μm by a gravure coating method to form a base film having a release layer. Created. Copper was vacuum-deposited on the melanin resin-coated surface of this substrate film by an induction heating method to a thickness of 1000 Å, and the surface of the film was used as a conductor, and then copper was deposited by electrolytic plating. The current density of electrolytic plating is 10 A / cm ²
The three kinds of metallized films having a plating thickness of 0.3 μm, 1 μm, and 3 μm were prepared by changing the plating time, and the finish of plating, peelability, adhesion, and workability were evaluated. .

As for the finished state of the plating, the appearance of the finished plated film of the metallized film was visually checked for the color of the plated layer, the rising, and the like. The finished state was good at any thickness, and no floating of the plating layer was observed. ◯ is indicated as good, and x is indicated as bad (Table 1).

Regarding the releasability, the portion of the metallized film cut out at a right angle and 5 mm from the corner was bent in a triangular shape, and it was confirmed whether or not the metal foil (copper foil) was broken. Any plating thickness of 0.3 μm, 1 μm, 3 μm,
Although the metal layer, which was the copper foil, was broken, it could be easily peeled off. ⊚ is indicated as excellent, ◯ is indicated as good, and × is indicated as bad (Table 1).

For adhesion, a metallized film of 10
The metal foil and the base material, which are cut out into a width of mm, are adhered to a pressure-sensitive adhesive film (Nichiban Cellotape (registered trademark) No. 405) as shown in FIG. The adhesion of the film was measured by peeling 180 ° with Tensilon (TG-500N, Minebea Co., Ltd.). FIG. 3 is a schematic side view showing a situation of measuring the adhesive force between the base film and the metal foil in the present invention,
Further, FIG. 5 is a perspective view showing a state in which the metal foil is peeled off from the metallized film of the present invention. The measurement results are shown in Table 1.

For the evaluation of the processing characteristics, the copper foil peeled from the base film was etched into a circular shape of φ10 μm by the photolithography method, and the reproducibility of the copper foil perforation processing with respect to the mask size was evaluated. The resist used for evaluation is FPPR-
30 (manufactured by Fuji Yakuhin Co., Ltd./trade name) was applied by a bar coating method so that the resist thickness after drying was 1 μm. After applying the resist, it is dried at 80 ° C. for 2 minutes, covered with a φ10 μm circular mask, subjected to UV exposure for 10 seconds from the top of the mask, and then developed at room temperature K of 1%.
It was washed with an OH aqueous solution for 45 seconds and washed with water. After that, the etching is performed for 10 seconds in a ferric chloride solution having a concentration of 0.5 ° Be for 10 seconds.
Immersion for 20 seconds. Plating thickness is 0.3μ
It was possible to perforate φ10 to 12 μm in the copper foil by etching for 5 seconds for m, 10 seconds for 1 μm, and 20 seconds for 3 μm. ◯ is indicated as good, and x is indicated as bad (Table 1).

Comparative Example 1 In the same manner as in Example 1, a metallized film having a plating thickness of 5 μm was prepared by changing the plating time and evaluated in the same manner as in Example 1. In the finished state, the color of the plating layer was good, but the phenomenon in which the copper foil deposited in the plating bath floated was observed. Moreover, the peelability is such that the copper foil can be peeled without breaking, and the adhesion is also slightly strong as shown in Table 1, but the holes in the etching process do not open in 5 seconds and become as small as φ7 μm in 10 seconds. , Φ16μm is too large in 20 seconds,
It was estimated that the processing conditions were extremely narrow and difficult to process.
The results are shown in Table 1.

(Comparative Example 2) A metallized film was prepared by forming a base film in the same manner as in Example 1 and subjecting the base film to vacuum deposition of copper to a thickness of 1000 angstroms by an induction heating method (without plating treatment). ) And the same evaluation as in Example 1 was performed. The finished state such as color and floating is good because it is only vapor deposition, but the metal layer is broken together with the base film when confirming the peelability because the copper layer is extremely thin. However, the copper foil was too thin to break during the measurement, and the measurement could not be performed. In confirming the processing characteristics, it was possible to drill a hole of φ12 μm in the copper foil by etching for 5 seconds. The results are shown in Table 1.

Comparative Example 3 A copper foil having a thickness of 35 μm was coated with silicone oil as a release agent, baked at 250 ° C., washed with alcohol, and then electrolytically plated to deposit copper to a thickness of 2 μm. Then, a copper foil with a carrier copper foil was prepared. The finished state is good with no appearance color or floating, but since the carrier material is copper foil, the copper foil of the carrier material and the metal layer were broken together with the base film, and adhesion was also confirmed. Also in the measurement of, since the metal layer to be the copper foil was thin, the foil broke during the measurement and the measurement could not be performed. In confirming the processing characteristics, it was possible to drill a hole of φ11 μm in the copper foil by etching for 5 seconds. The results are shown in Table 1.

[0037]

[Table 1]

[0038]

As described above, in the metallized film of the present invention, a plastic film having a release layer is used as a base film to form a metal layer on the release layer by vapor deposition, and the metal layer is plated by a plating method. Because of the growth, a thin metal layer (metal foil) can be easily and accurately provided on the base film.

Further, the adhesive force between the vapor-deposited metal film and the release layer can be adjusted by the vapor deposition method and the material of the vapor-deposited metal film and the release layer. Conventionally, the metal layer is peeled off from the base film. It becomes possible to obtain an ultra-thin metal foil that does not exist in the above, and it is possible to significantly improve the fine processing precision of the metal foil.

[Brief description of drawings]

FIG. 1 is a schematic side view for explaining a conventional electrolytic foil production process.

FIG. 2a is a schematic side view for explaining an electrolytic foil production apparatus using a conventional carrier foil. Figure 2b
[Fig. 2] is a cross-sectional view showing a configuration of an electrolytic foil produced by using the production apparatus of Fig. 2a.

FIG. 3 is a schematic side view showing a situation in which the adhesive force between the base film and the metal foil in the present invention is measured.

FIG. 4 is a cross-sectional view illustrating the configuration of the metallized film of the present invention.

FIG. 5 is a perspective view showing a state in which the metal foil is peeled off from the metallized film of the present invention.

[Explanation of symbols]

(1) Electrolytic drum (2) Electrolyte (3) Electrolyte container (4) Washing tank (5) Copper foil for carrier (6) Plastic film (7) Release layer (8) Evaporated metal film (9) Metal coating

Front page continuation (51) Int.Cl. ⁷ Identification code FI theme code (reference) H05K 9/00 H05K 9/00 W (72) Inventor Takashi Suzuki 1 Toyo Metallic Co., Ltd., 33 Nagabushi, Mishima City, Shizuoka Prefecture F term in Mishima plant (reference) 4F100 AB01D AB01E AB17 AB33D AB33E AJ04B AJ04C AJ11B AJ11C AK25B AK25C AK36B AK36C AK42 AK52B AK52C AT00A BA03 BA05 BA06J06JKJJ06J11KJK06KJKJE14KJE06KJKJE14KJE14KJE14KJE14KJE14KJE14KJE14KJEJ25JB14JJE14KJE14KJEJ25EBA25DBA25EBA25DBA25EBA25E AA10 AA11 AB01 BA12 BB27 BC02 DA09 EA12 4K029 AA11 AA25 BA08 BC03 CA01 GA05 JA10 KA03 5E321 BB23 BB44 BB60 CC16 GG05 5E346 CC32 CC37 CC38 CC39 DD12 HH26

Claims (5)

[Claims] 1. A metal film having a thickness of 0.3 μm to 8 μm and an adhesive force of 1 g / cm to 100 g / cm is provided on the release layer of a substrate film having a release layer on one side or both sides. Become a metallized film. 2. The metallized film according to claim 1, wherein the release layer of the base film contains any one of urea resin, silicone resin, cellulose resin, acrylic resin and wax. 3. The metallized film according to claim 1, wherein the metal layer contains AL, gold, silver, copper, nickel or chromium alone or an alloy and has conductivity. 4. A metal foil obtained by peeling a metal layer from the metallized film according to claim 1. 5. A metallized film, comprising: forming a vapor-deposited metal film by vapor deposition on a release layer of a substrate film having a release layer, and growing the metal film by a plating method to form the metal layer. Manufacturing method.