JPS63275194A - Formation of metallic pattern - Google Patents

Abstract

PURPOSE:To improve a metallic pattern in quality and formation efficiency by a method wherein a conductive film is provided on a substrate surface and an electroplating or an electroless plating are performed thereon, and thereafter a mask pattern is formed and subjected to etching. CONSTITUTION:For example, a conductive film 2 is formed on a substrate 1 of polyethylene terephthalate 25-75mum in thickness directly or through the intermediary of a parting layer. Next, a metallic film 3 of copper or nickel or the like is formed on a laminated body consisting of the substrate 1 and conductive film 2 provided on it through an electroplating or an electroless plating. A mask pattern 4 is formed on the plated metallic film 3 by means of a mask material, and etching is performed along the mask pattern 4 by using an adequate etching agent. In this process, an adquate etching agent should be chose according to the kind of metal composing a metallic film and a conductive film. By these processes, a metallic pattern can be obtained efficiently which is excellent in productivity and quality.

Description

[Detailed description of the invention] (Technical field) The present invention relates to a metal pattern forming method.

More specifically, the present invention relates to a method of forming a metal pattern that enables highly efficient and high-quality production of metal patterns useful as printed wiring boards, decorative plates, nameplates 1, etc.

(Background Art) Conventionally, flexible printed boards have been used in the manufacture of printed wiring boards in order to downsize and lower the cost of devices. In addition, recently, flexible pudding I
A deep-on-board method, in which IC chips are mounted directly on the board, is also being adopted.

In this case, high precision and high definition are required, with a pattern width of about three pins, and strong pattern adhesion strength is required to prevent peeling during bonding and other processes.

Manufacturing methods for such flexible prints include (a) a method in which a base film and silver foil are laminated, and then a pattern is formed using screen printing or a water-soluble dry film and etched; (b) a method in which a pattern is formed on the base film and then etched; An additive method in which a resist or ink pattern is formed by means such as dry film or screen printing, then copper is deposited by electroless plating or electrolytic plating, and then a conductor pattern is formed by removing the mask pattern, or (1) A method is known in which a copper thin film is formed on a base film in a vapor phase using a cluster ion beam or the like, and a conductor pattern is formed by a subtractive method.

However, many problems still remain with these manufacturing methods. First of all, in (a) the lamination method, the silver foil cannot be made thinner, and high definition is difficult to achieve because thick silver foil is etched.Moreover, when using various metal conductors, the masking material is removed by the etching agent. dissolves, making it difficult to use a variety of metal films.

The following (a) additive method requires surface treatment and etching using a mixed solution of high concentration chromic acid and sulfuric acid in order to perform electrolytic or electroless plating on the surface of a plastic film.

These treatment agents induce pollution, and the manufacturing process and equipment required to counteract it become complicated, resulting in high costs.

Furthermore, in the case of gas phase method and subtractive method,
Conventional methods have a slow film formation rate and require long operations to obtain the desired film thickness, resulting in poor productivity and high costs.

At present, it is unclear whether decorative plates or nameplates can be manufactured using the same method, and whether the above-mentioned problems still remain. Furthermore, when forming the metal film by vapor deposition, the adhesion of the metal film is poor and it is not easy to increase the film thickness.

For this reason, it has been desired to realize an improved metal pattern printed board and its manufacturing method that overcomes the drawbacks of conventional lamination methods, additive methods, and even vapor phase methods.

(Objective of the Invention) The present invention has been made in view of the above-mentioned circumstances, and provides a new metal pattern forming method that is highly productive and capable of efficiently manufacturing high-quality metal patterns. The purpose is to

More specifically, it is an object of the present invention to provide a flexible printed wiring board having a high-definition, multilayer metal pattern, as well as a decorative play plate 1 to a nameplate, and a method for manufacturing the same.

(Disclosure of the Invention) In order to achieve the above object, the metal pattern forming method of the present invention includes forming a conductive film on the surface of a substrate, performing electrolytic plating or electroless plating, and then forming a mask pattern and performing etching. It is characterized by doing.

Further, as a related method, the present invention provides a method in which a conductive film is provided on the surface of a substrate, a mask pattern is formed, etching is performed, and the conductive film pattern obtained by removing the mask is subjected to electrolytic or electroless plating. It is also a feature.

The method of the present invention eliminates the need to treat plastic surfaces with chromic acid/sulfuric acid, which was indispensable in conventional plating processes, by providing a conductive base film as a pre-process of electroless plating or electrolytic plating. It has the great advantage of being non-polluting, and the shape and film thickness of the metal pattern can be easily controlled.

The method of the present invention will be explained in more detail with reference to the attached drawings. FIG. 1 shows the method of the invention.

As shown in Figure 1, (a) For example, PET with a thickness of about 25 to 75 μm (
A conductive film (2) is formed on the surface of a substrate (1) of polyethylene terephthalate (1-) directly or via a release layer.

The substrate (1) is not limited to PET, and any film or plate of relatively heat-resistant plastic such as polyester, nylon, polyamide, polyimide, polysulfone, etc. can be used. It may also be a laminate.

Further, as the mold release layer, a thermosetting resin or a UV curing resin can be used. When used as a printed circuit, the material and thickness of the release layer are appropriately selected so that soldering during component mounting may have sufficient conductivity.

A protective film can also be formed by using a transparent inorganic compound such as S When obtaining a conductor pattern such as a circuit, it is preferable to use an extremely thin layer of 50 to 100 A.

The conductive film (2) can be formed by a vapor phase process such as vacuum evaporation or plasma ion beam deposition. In some cases, wet plating may be used. In addition, the board (
The conductive film (2) may be formed after forming an extremely thin film of a metal such as gold (80) which has weak adhesion to the film (1).

This conductive film (2) may be any metal such as copper (Cu), aluminum (81), silver (8g), nickel (Ni), titanium (Ti), zinc (Zn), etc. is used. Inorganic materials such as indium oxide, tin oxide, and ITO may also be used. Since ITO is a transparent thin film, it is useful for either decorative play +-1 or print 1- circuits with interference colors. It is also possible to use ITO that is not colored by electrophoresis.

The thickness of this conductive film (2) is preferably 0.5 to 1 μm.
That's about it.

(b) Next, the laminate in which the conductive film (2) is disposed on the substrate (1) is coated with copper (Cu) by electrolytic or electroless plating.
), a metal film (3) of nickel (old), etc. is formed. The thickness of the plating layer is not particularly limited, and in the case of a printed circuit conductor, it can be as thick as, for example, about 1 to 30 μm.

(C) On this plated metal Wi (3), a mask pattern (4) is then formed using a masking material.

As this masking material, water-soluble starch, polyvinyl alcohol, other water-soluble colored inks, water-soluble dry films, or oil-based resins such as acrylic, epoxy, and amide resins may be used.

These masking materials are formed into a mask pattern (4) by a screen printing method, a photolithography method using a dry film, or the like.

(d) Next, when etching is performed using an appropriate etching agent along the mask pattern (4), the etching agent is appropriately selected depending on the metal forming the metal film and the type of conductive film.

The plated metal film and the conductive film may be etched simultaneously or separately, or the conductive film may be left as is without being etched. Table 1 illustrates the relationship between the types of plated metal films and conductive films and etching agents.

This etching results in the desired metal pattern (5).

The metal pattern printed board can be used as it is as a printed circuit board, or alternatively, as shown in Figure 2, it can be attached to a substrate (6) such as a plastic board or a laminate board using an adhesive. Then, the substrate (1) can be peeled off and used.

Furthermore, as shown in FIG. 3, another substrate (7) can be attached to the surface of the metal pattern to be used as a decorative plate or a name plate. Adhesive Table-1 may also be used.

Instead of the above method, etching may be performed along a mask pattern to form a conductive film pattern before electroplating or electroless plating.

Examples of the above method will now be described.

Of course, the invention is not limited to the following examples.

Example An ITO thin film of 0.6 μm was formed on the surface of the PET film by plasma ion beam deposition. IT is carried out while moving at a speed of 18 m/min using a pressure gradient type ion brating device that uses rolls, rolls, and rolls.
An O thin film was formed. Next, a thin copper film having a thickness of 20 μm was formed by electroless plating.

A pattern was formed using a water-soluble ink as a mask, and copper was etched using a copper VII acid and iron chloride solution. Subsequently, the ITO base film was etched using caustic soda.

I T″0/P E 'l'' with copper multilayer pattern
Lay out the base film laminate.

After forming through holes on this, use it as a printed circuit and mount electrical components.

(Effects of the Invention) This invention makes it possible to form high-quality metal patterns with good productivity.

The metal pattern printed board according to the present invention is useful not only as a printed circuit but also as a decorative pattern.

[Brief explanation of the drawing]

FIGS. 1(a), (b), (c), and (d) are process diagrams showing the method of the present invention. FIGS. 2 and 3 are sectional views each showing an example of use of the metal pattern printed board of the present invention. DESCRIPTION OF SYMBOLS 1... Substrate, 2... Conductive film, 3... Plated metal film, 4... Mask pattern, 5... Metal pattern,
6.7...Substrate. Representative patent attorney Toshio Nishizawa = 12- Figure 1 Figure 2 Figure 3

Claims (2)

[Claims] (1) A method for forming a metal pattern, which comprises providing a conductive film on the surface of a substrate, performing electrolytic or electroless plating, and then forming a mask pattern and performing etching. (2) A method for forming a metal pattern, which comprises providing a conductive film on the surface of a substrate, forming a mask pattern, etching it, removing the mask, and performing electrolytic or electroless plating on the conductive film pattern obtained.