JP2003059749A - Metal film transfer film for electronic component - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a plastic film where a metal film for forming an electrode composing electronic components by transfer is formed, especially a metal film transfer film for electronic components having improved transfer properties. SOLUTION: In the metal film transfer film for electronic components having a mold release layer, the mold release layer and a metal layer are formed on a plastic film in this order, the release strength between the plastic film and the metal film is 0.1-30 g/10 mm wide, and the release strength after heat treatment for 30 minutes at 160 deg.C is 0.1-30 g/10 mm wide.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a material for electronic parts, and more particularly, when forming an electrically conductive metal film on an electronic part, a metal thin film transfer used by transferring from a plastic film having a metal film formed thereon. It's about film.

[0002]

2. Description of the Related Art Conventionally, as a method of forming electrodes of electronic parts, for example, in the production of semiconductor circuits, etc., after a metal film is formed directly on a substrate by plating or vapor deposition,
A method of performing patterning by photolithography or the like is known.

In a monolithic ceramic capacitor, a green sheet is first prepared by a doctor blade method using a slurry composed of a dielectric powder such as barium titanate, an organic binder, a plasticizer and an organic solvent, and then. An internal electrode is formed on the green sheet by screen printing using an electrode paste containing a noble metal such as palladium, nickel or platinum as a main component. Next, the green sheets on which the internal electrodes are formed are arranged so that the internal electrode layers are alternately opposed to each other with the ceramic dielectric layer interposed therebetween, and are sequentially laminated, and the lamination is repeated up to a desired number of layers to form a ceramic laminated body. . Next, the ceramic laminate is adhered onto a metal plate provided with an adhesive film, and this is compression-molded in order to improve the adhesion between the layers of the ceramic laminate. Further, the ceramic laminated body thus formed is cut into chips having a desired size and fired at 1200 to 1400 ° C. The external electrodes are formed by applying silver or silver-palladium to the internal electrodes appearing at both ends of the thus obtained sintered body so that these internal electrodes are electrically connected and baking them. And manufactures monolithic ceramic capacitors.

In recent years, in particular, in the case of monolithic ceramic capacitors, the demand for light, thin, short and compact mobile devices typified by mobile phones and personal digital assistants has been increasing, and further miniaturization has been achieved. -A large capacity is becoming an issue. Conventionally, in the manufacturing process of a monolithic ceramic capacitor, as a means for realizing a small size and a large capacity, there is known a method of reducing the thickness of each laminated ceramic dielectric sheet and increasing the number of laminated layers.

[0005]

However, when the ceramic dielectric sheet is thinned, since the green sheet is thin, the internal electrode paste penetrates into and penetrates the fine pores existing on the sheet, resulting in poor insulation. Problems such as occurrence may occur.

The inventors of the present invention, for example, in a laminated ceramic capacitor, prepare a plastic film on which a metal film is formed instead of the conventional printing method using a paste for the internal electrodes, and use this metal film as a dielectric sheet. It has been found that the method of forming the internal electrode by the method of transferring onto the surface can solve the above-mentioned problems (Japanese Patent Application No. 2001-63634).
No.), the releasability between the plastic film and the metal film was not always sufficient.

[0007] Therefore, as a result of diligent studies on the subject, the present inventors found that if the peeling strength of the release layer after heat treatment under specific conditions is within a specific range, the releasability, that is, the transferability is improved. The present invention has been completed and the inventors have found that the value is significantly improved.

An object of the present invention is to provide a plastic film having a metal film formed by transferring electrodes constituting an electronic component, and in particular, a metal film transfer film for an electronic component having excellent transferability. To provide.

[0009]

The metal film transfer film for electronic parts of the present invention has a structure in which a release layer and a metal film are formed in this order on a plastic film. Peel strength with metal film is 0.1
~ 30g / 10mm width and 3 at 160 ° C
Peel strength after heat treatment for 0 minutes is 0.1 to 30 g / 10
A metal film transfer film for electronic parts, having a release layer having a width of mm.

[0010]

BEST MODE FOR CARRYING OUT THE INVENTION The metal film transfer film for electronic parts of the present invention will be specifically described below.

The metal film transfer film for electronic parts of the present invention can be obtained by forming a release layer on a plastic film and then forming a metal film.

The plastic film used here is a film made of an organic polymer material. Specific examples of the organic polymer material include polyethylene terephthalate, polyethylene naphthalate, amorphous polyolefin, polyarylate, polyethylene, Polypropylene, polyamide, polyimide, polymethylpentene, polyvinyl chloride, polystyrene, polymethylmethacrylate, polycarbonate, polyetheretherketone,
Polysulfone, polyether sulfone, fluororesin, polyetherimide, polyphenylene sulfide, polyurethane, cyclic olefin resin and the like can be mentioned, but polyethylene terephthalate is preferably used in terms of economy and strength.

The plastic film used in the present invention may be used in the form of a sheet or a roll, but a roll-shaped plastic film is preferable because vapor deposition can be continuously performed.

The thickness of the plastic film is preferably in the range of 8 to 250 μm, more preferably 12 to 188 μm. When the thickness is less than 8 μm, the film is deformed by the radiant heat generated from the evaporation source during metal vapor deposition, which is not preferable. As a method for measuring the thickness of the plastic film, a method using a measuring device such as a micrometer, a method of calculating from the mass of the film sample collected using its specific gravity, and the like can be used.

In the metal film transfer film for electronic parts of the present invention, the peel strength between the plastic film and the metal film is important.

As an index of the peel strength between the plastic film and the metal film, an adhesive tape was attached to the metal film side, the adhesive tape and the plastic film were slit into a constant width of 10 mm, and then a tensile tester was used to measure 1000 mm / min. The peel strength when peeling the both into a T shape at a speed can be used.

The metal film transfer film for electronic parts of the present invention has a peel strength between the plastic film and the metal film of 0.
The width is 1 to 30 g / 10 mm and the peel strength after heat treatment at 160 ° C. for 30 minutes is 0.1 to 30 g / 1.
It is necessary to have a release layer with a width of 0 mm.

The peel strength between the plastic film and the metal film is preferably 0.1 to 20 g / 10 mm width,
And the peel strength after heat treatment at 160 ° C. for 30 minutes is 0.1 to 20 g / 10 mm width, more preferably 0.1 to 10 g / 10 mm width, and 160 ° C.
Peel strength after heat treatment for 30 minutes at 0.1-1
The width is 0 g / 10 mm. Peel strength is 0.1g / 10m
When the width is less than m, the vapor-deposited metal film is likely to be easily peeled off due to external force, friction, etc.
On the other hand, if the width exceeds 30 g / 10 mm, it is not preferable because it is not transferred or the metal film is cracked when transferred. Regarding the multilayer ceramic capacitor, the release layer after the metal film is transferred to the ceramic dielectric sheet is
It may remain on the film side or may remain on the metal film side.

In the present invention, the release layer may be a single layer, but two or more layers having different compositions may be used in combination.

Silicone resin, melamine resin, epoxy resin or fluororesin can be mentioned as the main component constituting the release layer in the metal film transfer film for electronic parts of the present invention. In the present invention, at least these resins are used. It is preferable to use one kind.

In the present invention, the release layer can be provided by applying a coating liquid containing the constituents to a plastic film, heating and drying it, and optionally curing it by irradiation with ultraviolet rays. As a coating method of the coating liquid, a known coating method can be applied, and examples thereof include a roll coater method. An organic solvent or an aqueous coating liquid can be used as the coating liquid, but an organic solvent is preferably used because it dissolves an organic compound. The thickness of the release layer is usually preferably 0.01 μm to 5 μm, more preferably 0.05 to 3 μm. When the thickness of the release layer is less than 0.01 μm, sufficient effect cannot be obtained due to coating omission, and when the thickness exceeds 5 μm, sufficient improvement of the release effect cannot be expected, and the economy is low. It is not preferable because it is disadvantageous. As a method of measuring the thickness of the release layer,
It can be measured by using a transmission electron microscope, a scanning electron microscope, a micrometer, or the like.

The metal species constituting the metal film of the metal film transfer film for electronic parts according to the present invention differ depending on the electronic parts used, and examples thereof include nickel, palladium, platinum, gold and silver. When used as an electrode, nickel alone is preferable,
For the purpose of improving the film characteristics obtained by nickel, other metals may be added within a range that does not significantly impair the properties of nickel such as electric characteristics and corrosion resistance. Examples of other metals include chromium, copper, tin, aluminum and palladium. The upper limit of the mixing ratio of these other metals is preferably 20% by weight.

As the method for forming the metal film in the present invention, sputtering, vapor deposition or the like can be used, and among them, the metal film obtained by vapor deposition is preferable. In addition, examples of the vapor deposition method include induction heating, resistance heating, sputtering, electron beam (EB), and ion plating, but electron beam vapor deposition is particularly preferable in terms of productivity and vapor deposition film quality. is there.

The thickness of the metal film in the present invention is preferably in the range of 500 to 20,000 angstroms,
The range is more preferably 500 to 10000 angstroms, and further preferably 500 to 5000 angstroms. If the thickness is less than 500 angstrom, it is not preferable because it is easily broken in the transfer process and sufficient electric characteristics cannot be obtained, while the thickness is 20,000.
If it exceeds angstroms, the film thickness becomes thicker, which is not preferable because the advantage of thinning cannot be obtained and the metal film is apt to crack. The thickness of the metal film is
It can be measured using a transmission electron microscope, a scanning electron microscope or the like.

The metal film transfer film for electronic parts according to the present invention is used by further transferring the metal film formed on the plastic film having the release layer formed thereon as described above onto the electronic part.

For example, as a method of transferring the metal film onto the dielectric sheet of the monolithic ceramic capacitor, the metal film transfer film and the ceramic green sheet are superposed and then pressure-bonded by using a pressure roller or a press. rear,
The method of peeling a plastic film can be mentioned. In this case, it is also possible to heat at a temperature not higher than the glass transition temperature or melting point of the plastic film. Further, the dielectric sheet having the patterned metal film internal electrodes can be processed into a multilayer ceramic capacitor by a conventional process.

The dielectric sheet is usually obtained by forming a slurry of a dielectric powder containing barium titanate or the like as a main component, an organic binder, a plasticizer and an organic solvent into a film by a doctor blade method or the like, and subsequently drying it. It is obtained by cutting the sheet into a predetermined size and then firing. The dielectric sheet has a thickness of 0.5 to 3
It is 0 μm, preferably 0.5 to 15 μm.
If it is less than 0.5 μm, defects such as pinholes generated in the dielectric sheet gradually increase, while if it exceeds 30 μm, those satisfying the miniaturization and large capacity of the laminated ceramic capacitor in which the dielectric sheets according to the present invention are laminated are satisfied. I can't get it.

The internal electrode pattern in the laminated ceramic capacitor can be formed by combining an electrode pattern having a predetermined shape and size with a lithography method using a resist.

The metal film transfer film for electronic parts of the present invention is suitable as a method for forming thin film electrodes of electronic parts by transfer, and examples thereof include internal electrodes of semiconductor circuits and laminated ceramic capacitors. In particular, it is suitable as a method for forming an internal electrode of a monolithic ceramic capacitor.

[0030]

EXAMPLES The metal film transfer film for electronic parts of the present invention will be described in detail with reference to examples.

Example 1 A melamine resin-based release agent was applied onto a polyethylene terephthalate film having a thickness of 25 μm to obtain a plastic film with a release layer. A pressure-sensitive adhesive tape (made of polyethylene terephthalate film) was attached to this surface by applying a load with a rubber roller, aged at room temperature for 24 hours, and the peeling force was measured by a tensile tester. As a result, it was 3 g / 10 mm width. . Next, this plastic film with a release layer was left in a hot air oven at 160 ° C. for 30 minutes, then cooled to room temperature, and an adhesive tape (made of polyethylene terephthalate film) was applied to this surface by applying a load with a rubber roller. After being combined and aged at room temperature for 24 hours, the peeling force was measured by a tensile tester. As a result, the peeling force did not change at a width of 3 g / 10 mm.

Next, a film thickness of about 3000 is formed on the release layer of the plastic film with the release layer by electron beam evaporation.
A metal film transfer film was formed by depositing angstrom metal nickel. An adhesive tape (made of polyethylene terephthalate film) was attached to the metal nickel film surface by applying a load with a rubber roller, aged at room temperature for 24 hours, and then the peeling force was measured by a tensile tester. The peeling force was 1 g / 10 mm width.

Separately, the composition of the dielectric material is BaTi.
A mixed powder of an oxide containing O ₃ as a main component and BaZrO ₃ as an additive was dispersed in dibutyl phthalate together with a polyvinyl butyral resin binder to obtain a ceramic slurry. This ceramic slurry,
By a doctor blade method, a silicone resin release agent is applied to one side of a carrier film made of polyethylene terephthalate having a thickness of 38 μm, dried at 120 ° C., and cut into a size of 100 mm × 100 mm,
A ceramic green sheet having a thickness of 2 μm was prepared.
On the ceramic green sheet, the metal nickel film of the metal film transfer film that was already prepared was transferred by hot pressing. Next, the ceramic green sheets on which the internal electrodes are formed are stacked by alternately shifting them with a certain size, pressed and pressed, and then cut, and the green chip of the multilayer ceramic capacitor in which the internal electrode parts are alternately exposed from both end faces. And Next, this green chip was forcedly vibrated in sawdust to chamfer the ridgeline portion of the prism. Then, the above various external electrode pastes were applied by a dipping method to both end surfaces of the chamfered green chip where the internal electrode portions were alternately exposed. 1 at 120 ° C after coating
It was dried for 5 minutes. The coating film thickness after drying was formed to be about 35 μm. This is heat-treated in the air for 30 hours at a maximum temperature of 370 ° C. for 3 hours, and then, in a reducing atmosphere with respect to nickel, specifically, at 1/100 of the equilibrium oxygen partial pressure of nickel at 600 ° C. or higher. In an atmosphere in which the oxygen concentration was controlled for 18 hours and at a maximum temperature of 1300 ° C. for 3 hours, heat treatment and firing were performed to obtain a sintered body, and a multilayer ceramic capacitor was obtained.

The 100 monolithic ceramic capacitors obtained as described above were measured and inspected for capacitance. Regarding the electrical characteristics, those having an abnormal capacitance value of 30% or less of the normal value were considered to be defective. As a result, the defect rate is 0
%Met.

(Example 2) A film with a release agent was obtained in the same manner as in Example 1 except that a silicone resin was used as the release agent. Peel force with adhesive tape is 4g / 1
The width was 0 mm, and the peeling force after heat treatment at 160 ° C. for 30 minutes was 8 g / 10 mm width. A metal nickel film was formed on the release layer of the release layer-attached film in the same manner as in Example 1, and the peeling force was measured. As a result, the width was 1.5 g / 10 mm.

Next, this metal film transfer film was transferred to a ceramic green sheet in the same manner as in the example to obtain a laminated ceramic green sheet. As a result of measuring and inspecting the capacitance of 100 laminated ceramic capacitors, the defective rate was 7%.

Comparative Example 1 A film with a release agent was obtained in the same manner as in Example 1 except that a urethane acrylic resin was used as the release agent. Peeling force with adhesive tape is 4
Although the width was g / 10 mm, the peeling force after heat treatment at 160 ° C. for 30 minutes was 55 g / 10 mm width. A film of metallic nickel was formed on the release layer of the film with the release layer in the same manner as in the example, and the peeling force was measured. As a result, 120 g / 1
It was 0 mm wide.

Next, this metal film transfer film was transferred to a ceramic green sheet in the same manner as in the example to obtain a laminated ceramic green sheet. As a result of measuring and inspecting the electrostatic capacitance of 100 laminated ceramic capacitors, the defective rate was 80%.

Comparative Example 2 A film with a release agent was obtained in the same manner as in Example 1 except that a urethane acrylic resin was used as the release agent. The peeling force by the adhesive tape is 5
The width was g / 10 mm and the peel force after heat treatment at 160 ° C. for 30 minutes was 95 g / 10 mm. A film of metallic nickel was formed on the release layer of the film with the release layer in the same manner as in the example, and the peeling force was measured. The result was 200 g / 10 m.
The width was at least m.

Next, this metal film transfer film was transferred to a ceramic green sheet in the same manner as in the example, but the metal nickel film was difficult to peel off, many cracks occurred on the film, and internal electrodes could not be formed.

[0041]

As is apparent from the above description, according to the present invention, a metal film transfer film for electronic parts, which is excellent in the releasing property of the metal film, that is, the transfer property, can be obtained.

   ─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor Masaru Suzuki             Toyo Metalai, 33 Nagabushi, Mishima City, Shizuoka Prefecture             Jing Co., Ltd. Mishima Factory (72) Inventor Toro Kobayashi             Toyo Metalai, 33 Nagabushi, Mishima City, Shizuoka Prefecture             Jing Co., Ltd. Mishima Factory F-term (reference) 4F100 AB01C AB16C AK01A AK17B                       AK36B AK52B AK53B AL05B                       AR00B BA03 BA07 BA10A                       BA10C EC04 EH66C GB41                       JG01 JJ03B JK06 JK06B                       JL14B JM02C YY00B YY00C                 4K029 AA11 AA25 BA02 BA12 BC00                       BD00 BD02 CA01 GA05                 5E001 AB03 AH09 AJ01

Claims (6)

[Claims] 1. A structure having a release layer and a metal film formed in this order on a plastic film, and the peel strength between the plastic film and the metal film is 0.1 to 3.
The width is 0 g / 10 mm and the peel strength after heat treatment at 160 ° C. for 30 minutes is 0.1 to 30 g / 10 mm.
A metal film transfer film for electronic parts, having a release layer having a width. 2. The metal film transfer film for electronic parts according to claim 1, wherein the release layer is made of at least one of silicone resin, melamine resin, epoxy resin and fluororesin. 3. The metal film transfer film for electronic parts according to claim 1, wherein the metal film is formed by vapor deposition. 4. The metal film transfer film for an electronic component according to claim 1, wherein the electronic component is a monolithic ceramic capacitor. 5. The metal film transfer film for electronic parts according to claim 4, wherein the metal film is a metal whose main component is nickel. 6. A monolithic ceramic capacitor formed by transferring the metal film of the metal film transfer film for electronic parts according to claim 1 onto a ceramic green sheet to form internal electrodes.