JPH0523005B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to a method for manufacturing a tape electric wire, and more particularly to a method for manufacturing a flexible tape-like or sheet-like electric wire in which a metal is firmly deposited on a base plastic film. Conventionally, this type of tape electric wire, that is, a tape-shaped or sheet-shaped electric circuit, was obtained by (a) pasting a thin copper foil on a tape and forming an electric circuit by etching, or (b) forming a flat metal conductor. They were obtained by arranging them and pasting them on sheets, etc. However, the thickness of the conductor used in this case is 18 μm or more, and there is a limit in handling when a conductor thinner than that is attached to a film or sheet for etching. Recently, in the field of electronics, there has been a demand for extremely thin tape- or sheet-shaped electrical circuits. In order to meet this demand, the inventors conducted extensive research and established the method of the present invention. That is, in the method of the present invention, (a) there is no need to attach metal to a plastic film one by one using the usual method, and (b) an extremely thin tape electric wire can be easily obtained. (2) To provide a method for manufacturing tape electric wire that has excellent adhesion between the base material and metal through special pretreatment, and that (2) enables continuous production and eliminates so-called handling problems. That is. The method for producing a tape electric wire according to the present invention involves degassing a plastic film by heating under a pressure of 10 ^-1 Torr or less, then micro-etching the film surface using a bombardment, and then evaporating the film. The method is characterized in that a metal is deposited on the surface of the film to a thickness of 300 Å to 50,000 Å using physical vapor deposition means with a particle energy of 1 eV or more, and then a conductor portion is formed by etching. The plastic serving as the substrate in the present invention may be a thermoplastic or thermosetting resin such as polyester, polyamide, polyimide, polyamideimide, polycarbonate, fluororesin, polyolefin, etc., but especially fluororesin. is preferred. The thickness of the base film is from 2 to 100 .mu.m, and usually about 5 to 50 .mu.m. The physical vapor deposition means in the present invention refers to coating methods using various metal vapors that do not involve chemical changes, such as ordinary vacuum vapor deposition, sputtering, and ion plating, and usually at a vacuum level of 10 ^-3 Torr or less. The metal is coated on the base film by ionizing the metal in the atomic or molecular state by some means, or by blowing the metal in the atomic state. The energy of the evaporated particles differs depending on the method, but if it is 1 eV or more, the sputtering method, ion plating method, etc. are equivalent methods. This is why, in these vapor deposition methods, in the present invention, it is desirable that the particles have large energy in order to deposit the metal onto the plastic film with strong adhesion. However, in addition, cleaning of the substrate is extremely important. In order to adhere metal to a substrate with good adhesion prior to physical vapor deposition, first heat the substrate film under a vacuum pressure of 10 ^-1 Torr or less to remove moisture, gas, monomers, etc. in the substrate film. Degassed. The heating temperature of the base film at this time is desirably 60° C. or higher, and it is desirable to raise the temperature to a degree that does not affect the base film as much as possible. Moreover, the heating time is preferably 15 seconds to 5 minutes. Next, a micro-etching process is performed on the film surface by bombardment, but as with the thermal degassing process, the base film is exposed to helium, argon, neon, nitrogen, and oxygen under a vacuum pressure of less than 10 ^-1 Torr.
Treatment is performed using one or more of RF plasma, DC glow discharge, etc. When the base film is placed in plasma, the surface of the base film is bombarded with electrons and ions and micro-etched. As a result, when metal is deposited on the surface of this substrate,
It can exhibit high adhesion. The bombardment time is about 10 seconds to 6 minutes, and even if the treatment is carried out for a short period of time, the adhesion becomes extremely high.
In particular, it is optimal as a means for increasing the adhesion to fluororesins such as fluorinated ethylene-propylene copolymer (FEP). Therefore, in the present invention, prior to physical vapor deposition, the base film is heated and degassed in vacuum, and then the surface of the base film is treated with bombardment to remove the energy of the evaporated particles.
Metal is deposited on the surface of a substrate to a thickness of 300 Å to 50,000 Å using physical vapor deposition means of 1 eV or higher. Furthermore, a conductor part is formed by etching,
A so-called tape electric wire in the form of a tape or sheet is obtained. The thickness of the metal layer by said physical vapor deposition means is 300 Å to 50000 Å, but 300 Å to 50000 Å.
The reason why the thickness should be more than 50,000 Å is due to the electrical characteristics of the conductor, and if it exceeds 50,000 Å, distortion may occur and flexibility may deteriorate. Usually the metal layer thickness is 500Å~
It is 20000Å. The above-mentioned etching in the present invention means removing the thin metal layer conductor sputtered on the surface of the film substrate, leaving it in the necessary areas.
Etching is carried out by the usual photoresist etching method, but since the thickness of the conductor is 300 Å to 50,000 Å, the etching time is short and a fine pattern can be formed. Next, the present invention will be further explained with reference to Examples. Example Base plastic film (thickness
25μ) in a 10 ^-3 Torr vacuum chamber, (A) heating with a sheathed heater (100℃, 2 minutes), (B) DC glow discharge (2 minutes),
(C) was coated continuously to a thickness of 2500 Å by sputtering copper after processing (A) and (B) separately. Comparative Example The same plastic film as in the above example was used.
Copper was continuously coated to a thickness of 2500 Å by sputtering in a vacuum chamber at 10 ^-3 Torr without any pretreatment. The copper adhesion of the copper-deposited films obtained in Examples and Comparative Examples was measured by the adhesion measurement method shown in FIG. 1. The results are shown in Table 1. The adhesion force was measured by attaching a cylindrical rod to the surface of the conductor layer 3 of each sample 1 consisting of a plastic film 2 as a base and a metal conductor layer 3 adhered thereon via an adhesive layer 4 made of epoxycemedine. 5 and pull this cylindrical rod 5 to obtain the tensile force (Kgf/
mm ² ).

[Table] As is clear from the above examples, by heating and bombarding in vacuum to adhere metal, a tape electric wire having extremely high adhesion between the base film and the deposited metal can be obtained.

[Brief explanation of the drawing]

FIG. 1 is a schematic explanatory diagram showing a method for measuring the adhesion force between a vapor-deposited metal and a plastic film, which is carried out according to the method of the present invention. DESCRIPTION OF SYMBOLS 1...Sample, 2...Plastic film, 3...Metal conductor layer, 4...Adhesive layer, 5...
...Cylindrical rod.

Claims (1)

[Claims] The plastic film is degassed by heating under a pressure of 1 10 ^-1 Torr or less, and then the film surface is micro-etched using a bombardment. A method for manufacturing a tape electric wire, which comprises depositing metal on the surface of a film to a thickness of 300 Å to 50,000 Å, and then forming a conductor portion by etching.