JPS63128616A - Manufacture of metallized film - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial Application Field) The present invention relates to a metal plated film, and more specifically,
The present invention relates to a metal plated film, which is particularly suitable for applications such as metal fixed resistors or sensors, in which a metal layer made of nickel and/or chromium is formed by plating.

(Prior art) Plastic films (typically polyethylene terephthalate films or polyimide films) are widely used as electrical insulating materials due to their excellent mechanical, electrical, and thermal properties. There are few examples of it being used as a body or metal coating fixed sensor. For applications such as resistors or sensors that use metal thin films as resistance elements, ceramic substrates such as alumina are used with high melting point metals such as nickel, chromium, and titanium formed on the surface by vapor deposition or sputtering. There is.

However, there are no examples of plastic films with various metal thin films formed on them being used as resistors or sensors, and even if they were used, there would be concerns about the adhesion between the film and metal film, cracking during processing and molding, and disconnection. Yes, but it was not usable.

On the other hand, it is known that layers made of simple metals such as a copper layer, a nickel layer, and a chromium layer are provided on a plastic film using a vacuum evaporation and Yasbuttering method, but a film having a thickness of 0.5μ or more is not known. Not yet.

(Problems to be Solved by the Invention) For plastic films laminated with aluminum paste, copper foil, chromium-based metal tubes, and nickel-based metal foils, thick foils of 15μ or more are used due to restrictions in handling metal foils. Therefore, it was difficult to form a metal layer thinner than this by bonding. Therefore, there were problems such as not being able to freely set a desired electrical resistance value and poor adhesion of the bonded portion.

On the other hand, thin metal layers of copper, nickel, chromium, etc. are formed on plastic films by vacuum evaporation and Yasbuttering, and because the thin metal layers are thin, they cannot be applied to circuits other than small current circuits. Furthermore, there are many problems such as poor moisture resistance and adhesion.

As disclosed in Japanese Patent Publication No. 61-16620, even if a relatively thick copper layer is formed by vapor deposition, the adhesion is poor and the application is limited to applications other than small current circuits.

Furthermore, it has been known that a thin copper layer is formed on a plastic film by vacuum evaporation or sputtering, and then the thickness of the copper layer is increased by electrolytic treatment. Even if the copper layer is eluted or peeled off, the adhesion is poor, and so far no product that can be used for practical purposes has been produced.

(Means for Solving the Problems) The present invention aims to solve the problems of these conventional techniques, and is particularly directed to a metal plated film suitable for applications such as fixed metal resistors or sensors using a film as a substrate. The purpose is to provide the following.

In order to achieve the above object, the present invention has the following configuration. That is, after providing a resin layer on at least one side of the plastic film, a 100 to 3000 copper layer is deposited on the resin layer, and a 0.5 to 35μ nickel-based and/or chromium-based layer is further deposited on the copper layer. In a method for producing a metal plated film in which a metal layer consisting of is formed by an electroplating method, heat treatment is performed in one of the steps after providing the resin layer,
This is a method for producing a metal plated film, characterized in that the heat shrinkage rate when heated at 150'C for 30 minutes under substantially no tension is 0.5% or less.

Examples of the base plastic film used in the present invention include polyethylene terephthalate, polyethylene-2,
6-naphthalate, polyethylene-α, β-bis(2-
chlorphenoxyethane-4,4'-dicarboxylate), polyphenylene sulfide, polyetheretherketone, aromatic polyamide, polyarylate, polyimide, polyamideimide, polyetherimide, polyoxadiazole, and these Examples include halogen group or methyl group substituted products. Also,
It may contain these copolymers or other organic polymers. Additives known to these plastics,
For example, a lubricant, a plasticizer, etc. may be added.

Among the above plastics, particularly preferably used is a film obtained by biaxially stretching orienting an unstretched film obtained by melt-extruding a polymer containing 85 mol% or more of repeating units of the following formula to improve mechanical properties. .

(However, X represents H, CH3, F, CI group.) Also,
A film made of a polymer containing 50 mol % or more of the repeating unit of the following formula and produced by a wet or dry process, or a film obtained by biaxially stretching and/or heat treating the film is also preferably used.

(Here, X is H, CH3, F, CI group, m, n are O~
Indicates an integer of 3. ) The plastic film as the base material used in the present invention may be used as is, but it may also be subjected to commonly known surface treatments such as corona discharge treatment and other chemical and physical surface treatments to further improve adhesion. good.

A resin layer is then provided on at least one side of the plastic film. The material for this resin layer is selected from thermosetting resins and polyimide resins because it needs to have good adhesion to both the plastic film and the metal layer and to withstand post-processing such as etching. The thermosetting resin is preferably a saturated polyester resin with good adhesiveness and an epoxy and/or melamine resin added thereto. Also suitable are polyester polyols or acrylic polyols to which isocyanate is added, modified acrylic resins to which a curing agent is added, and epoxy resins to which a curing agent is added. Further, examples of the polyimide resin include polyimide, polyamideimide, addition polymerization type polyimide, and the like.

For information on types of plastic films and types of resin layers, please refer to the Adhesive Handbook or Special Issue of Industrial Materials (
vol, 33. No. 13.1985>.

Even when a thin copper layer is provided by vapor deposition or sputtering, these resin layers have good adhesion between the coating film and the thin copper layer, and will not peel off or elute during subsequent metal plating, etching, or soldering.

In order to maintain sufficient adhesion between the copper thin layer, metal layer, resin layer, and film layers even in the treatment performed after the copper thin layer and metal layer are applied, it is necessary to apply the resin layer and/or the copper thin layer. Heat treatment is performed after installation and/or after metal plating so that the heat shrinkage rate when heated at 150° C. for 30 minutes with virtually no tension is 0.5% or less. Heat treatment is usually dry heat at ioo~300'C, 2 seconds~10
If the heat shrinkage is carried out under the conditions of 10 minutes to 48 hours and/or 40 to 100° C., the heat shrinkage rate can be within the above range.

Further, it is preferable to carry out this heat treatment in any step after the formation of the thin copper layer in order to prevent deterioration of the thin copper layer due to humidity or oxidation.

150'C under virtually no tension before etching
A film whose thermal shrinkage rate when heated for 30 minutes is kept at 0.5% or less, preferably 0.3% or less, has a thermal deformation difference between the metal layer provided after electroplating and the support film base material. Since the number of the thin lines formed by etching is small, there is no problem of the thin wires formed by etching being lifted from the base material or being cut. Further, the copper thin layer is not partially eluted during the electroplating process.

The thickness of the thin copper layer provided by vapor deposition or sputtering is 100-3002, preferably 300-1200.
number of people, more preferably 400 to 1000 people. If the film thickness is less than 100 mm, the film is likely to be eluted during the electroplating process, and if it is thicker than 3000 mm, the film is likely to peel off after the electroplating process.

In the present invention, the vapor deposition of the copper layer and the metal plating can be performed on either one side or both sides.

A film with a thin copper layer formed under virtually no tension at 150°C
If the thermal shrinkage rate is 0.5% or less when heated at °C for 30 minutes, it is possible to form a nickel-based and/or chromium-based metal plating layer by electroplating. In addition to Ni, nickel-based materials include Ni-Fe, Ni-
Zn, Ni-Co, N1-Co-)1 ()i: various metals).

Alloys such as N1-P (Pniline compound), N1-B, Ni-Ni-Ni, Ni-W, and Ni-Cr are also preferably used.

The electroplating process consists of degreasing and acid activation treatment, striking, and plating steps to improve adhesion.

If the metal electroplating process is performed immediately after depositing the copper layer, the degreasing and acid activation treatments and strikes may be omitted. The current density feeding the copper thin layer is preferably 0.2 to I
OA/dm2, more preferably 0.5-2A/dm2
It is. Further, the electroplating can be performed by either electrolytic plating or electroless plating. The thickness of the formed plating is 0.1-15μ, preferably 0.5-13μ, more preferably 1.5-10μ. If it is less than 0.1μ, the reliability of the plating film cannot be said to be sufficient. If it is more than 15 μm, it takes time to form a film, which is poor in economical efficiency, and it is also unfavorable in terms of quality, as etching tends to occur at the edges of the circuit pattern during etching, and there is a risk of wire breakage due to bending. Although it varies depending on the resistance value required by the target resistor or sensor, it is particularly preferably about 1.5 to 10 μm from the viewpoint of workability and quality.

In the present invention, a highly conductive metal plating layer such as copper, silver, or gold may be further formed on the nickel-based and/or chromium-based plating layer.

(Example) The present invention will be further explained below with reference to Examples.

Examples 1 to 8 The coating materials shown in Table 1 were applied to a polyimide film "Kapton" (registered trademark) having a thickness of 50 .mu.m to a thickness of 0.5 .mu.m, and heat-treated at 150.degree. C. for 1 minute. Then 5X
Copper was vacuum-deposited using IO-'RORR, with the film thickness selected from a range of 200 to 2,000. Further 180℃.

Heat treatment was performed for 1 minute. Thereafter, nickel plating was performed under the conditions shown in Table 2, with a thickness selected within the range of 4 to 10 microns. The adhesion between the copper layer and the base material after nickel plating, etching property (etching rate), dimensional stability, and dimensional change rate were measured, and the results are summarized in Table 3. It was found that the stability of the nickel layer was superior to that of Comparative Examples 1 to 6, which will be described later.

Comparative Examples 1 to 6 Polyimide films with a thickness of 50μ were coated with an anchor coating in the same manner as in the examples, and those without an anchor coating were subjected to plating processing with or without heat treatment (these results are shown in Table 1). 1 as a comparative example).

Next, plating was carried out under the conditions shown in Table 2 while changing the plating time. As shown in Table 3, the metal thin film layer peeled off or eluted during the plating process, making it impossible to perform the desired electroplating process.

(Margin below) Table 1 Polyimide resin (effects of the invention) According to the present invention, a nickel-based and chromium-based metal layer of 0.5 to 1
It can be formed to a thickness of 5 μm, and can produce metal plated substrates with excellent adhesion that do not peel off even after processes such as pattern formation, etching, wiring, and assembly, as well as even after severe environmental tests. Furthermore, it is possible to form a thin metal layer that cannot be obtained with conventional laminates such as chrome foil and Niracle foil, and it can be applied to higher-density circuit patterns. The substrate of the present invention is useful as a high-quality and inexpensive resistor or sensor, and can also be used for fine pattern wiring boards such as ICs and LSIs, printed wiring boards, and laminated boards.

[Brief explanation of the drawing]

FIG. 1 is a schematic cross-sectional view of a nickel-plated film in which a resin layer, a copper vapor deposition layer, and a nickel plating layer are provided on one side according to the present invention, and FIG. FIG. 2 is a schematic cross-sectional view of a nickel-plated film in which layers are provided on both sides. In the figure, 1: Niblast film 2: Resin layer 3: Copper deposited layer 4: Nickel plating layer 5: Metal layer

Claims (7)

[Claims] (1) After providing a resin layer on at least one side of the plastic film, a 100-3000 Å copper layer is vapor-deposited on the resin layer, and a 0.5-35 μ nickel-based and/or chromium-based copper layer is further deposited on the copper layer. In a method for manufacturing a metal plated film in which a metal layer consisting of is formed by electroplating, heat treatment is performed in one of the steps after the resin layer is provided, and when heated at 150 ° C. for 30 minutes under substantially no tension. A method for producing a metal plated film characterized by having a heat shrinkage rate of 0.5% or less. (2) The plastic film is polyester, polyphenylene sulfide, polyether ether ketone,
2. The method for producing a metal plated film according to claim 1, wherein the film is made of a material selected from aromatic polyamide, polyimide, polyoxadiazole, and halogen group- or methyl group-substituted products thereof. (3) The method for producing a metal plated film according to claim 1, wherein the resin layer is made of a saturated polyester resin, an epoxy resin, and/or a melamine resin. (4) The method for producing a metal plated film according to claim 1, wherein the resin layer is made of a reaction product of polyester polyol and/or acrylic polyol and isocyanate. (5) The method for producing a metal plated film according to claim 1, wherein the resin layer is made of a modified polyacrylic resin and a curing agent. (6) The method for producing a metal plated film according to claim 1, wherein the resin layer is made of an epoxy resin and a curing agent. (7) The method for producing a metal plated film according to claim 1, wherein the resin layer is made of one selected from polyimide, polyamideimide, and addition polymerized polyimide.