JPS63274522A - Formation of mold pattern - Google Patents

Abstract

PURPOSE:To prepare a printed circuit board having a high quality metal pattern imparted thereto with good productivity, by transferring a preformed specific metal pattern to the surface of a molded body simultaneously with the molding of a mold. CONSTITUTION:A conductive film 3 is provided to the surface of a board 1 through a release layer 2 and a mask pattern 4 is formed on the conductive film 3 to perform etching and a conductive pattern 5 is obtained. next, a metal pattern 6 composed of copper or nickel is arranged on the conductive pattern 5 by electroplating. The obtained laminate of conductive pattern 5/metal pattern 6 is transferred to a molded body simultaneously with injection molding and, after molding, the board 1 is released. By this method, the transfer/formation of the metal pattern 6 and the molding of a mold can be simultaneously realized.

Description

DETAILED DESCRIPTION OF THE INVENTION (Technical Field) The present invention relates to a mold pattern forming method. More specifically, the present invention relates to a method of transferring and forming a metal pattern by integral molding simultaneously with the molding of a mold structure such as a device housing.

(Background Art) Currently, attempts are being made to form a conductive pattern on the back surface of the II casing and mount components thereon in order to make the device smaller and lower in price.

However, many problems still remain in the attempts made so far, and there are many drawbacks as a practical technology. In other words, additive methods have traditionally been used to form conductor patterns on equipment casings, in which resist or ink patterns are formed on injection-molded mold plates using dry film or screen printing, and then electroless Copper (Cu) is deposited by plating or electrolytic plating,
Next, the above-mentioned mask pattern is removed to form a conductor pattern.

However, this conventional additive method requires surface treatment of the plastic, which is etched using a mixture of high-concentration chromic acid and WE acid.

This highly concentrated chromic acid is a chemical that causes pollution, and its use requires special pollution prevention measures, which also causes an increase in the cost of the product. Furthermore, in the case of this additive method, the manufacturing process is complicated, quality control and cost reduction are difficult, and moreover, it is difficult to form a metal conductor pattern in the case of a molded body with a complicated shape.

For this reason, it has been strongly desired to realize a method for manufacturing a metal pattern printed structure that can efficiently form a conductor pattern on a device housing of an arbitrary shape.

(Object of the Invention) The present invention has been made in view of the above-mentioned circumstances, and is an object of the present invention to efficiently form a mold structure having a metal conductor pattern for a mold structure of an arbitrary shape. The purpose of the present invention is to provide a method for forming metal patterns that can be used to form metal patterns.

More specifically, the present invention aims to provide a method for manufacturing a printed circuit flN body by integral molding.

(Disclosure of the Invention) The mold pattern forming method of the present invention includes providing a conductive film on the surface of a substrate, forming a mask pattern, performing etching, removing the mask, and then molding a metal pattern obtained by electrolytic or electroless plating. It is characterized by being simultaneously transferred onto the surface of the molded body.

This method uses chromic acid/1. It is characterized by eliminating the need for acid treatment and being non-polluting. Further, a major feature of this method is that the transfer/formation of the metal pattern and the formation of the mold can be performed simultaneously.

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

As shown in Figure 1, (a) For example, PET with a thickness of about 25 to 75 μm (
Film substrate (1) such as polyethylene terephthalate)
A conductive film (3) is formed directly or via a release layer (2) on the surface of the mold.

The substrate (1) is not limited to PET, but may include films, sheets, etc. of relatively heat-resistant plastics such as polyester, nylon, polyamide, polyimide, etc.
Any material such as a plate can be used. In addition, thermosetting resin or υV curing resin can be used as the release layer (2).When soldering when mounting 6 components, the material and film of the release layer (2) may be adjusted to have sufficient conductivity. Select the thickness appropriately.

A protective layer can also be formed by using a transparent inorganic compound such as 5102 or TlO2. In this case as well, for example, when obtaining a decorative pattern, the film thickness is preferably increased, whereas when obtaining a conductive pattern such as a printed circuit, it is preferable to use an extremely thin layer of 50 to 100 A.

The conductive FIR (3) 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 the method of the invention, it is necessary to separate the metal pattern and the base film after integral molding, so gold (A), which has weak adhesion to the substrate (1), is used.
After forming a metal fi thin film such as u), a conductive base film (3) may be formed.

As this conductive film (3), any metal such as copper (Cu), aluminum (AI), silver (^g), nickel (Ni), titanium (Ti), zinc (2n), etc. can be used. . It may be an inorganic material such as indium oxide, tin oxide, or ITO.ITO forms a transparent thin film and is therefore useful for both decorative purposes and printed circuits. ITO colored by electrophoresis can also be used.

The thickness of this conductive film (3) is preferably 0.5 to 1 μm.
That's about it.

(b) On this conductive film (3), a mask pattern (4) is then formed using a masking material. Examples of this soot material include water-soluble starch, polyvinyl alcohol, other water-soluble colored inks, water-soluble dry films, oil-based thermosetting materials, and UV-curable acrylic, epoxy, and amide-based materials. Resin may also 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.

(C) Etching the conductive film along the mask pattern (4) using an appropriate etching agent.

In this case, the etching agent is appropriately selected depending on the type of conductive film.

For example, when the conductive film (3) is aluminum, caustic soda is used. Caustic soda can also be used in the case of ITO. Table 1 shows an example of the relationship between the conductive film to be etched and the etching agent.

By removing the mask (4), the conductive pattern (
5) is obtained.

(d) Next, a metal pattern (6) of copper (Cu), nickel (Ni), etc. is provided on this pattern (5) by electrolytic heat or electrolytic plating.

This thickness is not particularly limited, and for example, when used as a conductor for a printed wiring board, it can be about 10 to 30 μm.

Table 1 The metal pattern (6) of this conductor forming layer is then attached to a mold (7) and injection molded as shown in FIG. 7) is supplied from the supply passage (8).

This process also includes drilling holes in printed circuits, etc.
For example, this can be easily done by forming the hole (9) using a mold.

Injection molding conditions can be within the usual range. For example, regarding temperature, ABS resin (approximately 250
℃), polyimide (about 400℃), polyester (about 3℃), polyimide (about 400℃), polyester (about 3℃)
00°C).

In this injection molding, in order to increase the degree of adhesion between the mold and the metal pattern, a room temperature curing or UV curing adhesive layer such as methacrylic acid ester, epoxy, melamine, polyurethane, etc. is provided on the metal pattern. Both are valid.

In this example, since a film is used as the substrate, it can also be carried out continuously. Manufactured by roll-to-roll. In this case, by providing two sets of films with metal patterns formed thereon, metal pattern printed layers can be formed on both the front and back sides of the mold.

After molding, the substrate may be subjected to Ml.

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 2 μm was formed on the surface of a PET film by plasma ion beam deposition. An ITO thin film was formed using a roll-to-roll pressure gradient ion blating device while moving at a speed of 15 m/min.

Next, a pattern is formed using water-soluble ink as a mask,
Etched using caustic soda.

After etching, the mask is removed and copper (Cu) is coated with Fi1g by electroless plating. was patterned to a film thickness of 20 μm.

The obtained PET base film having the ITO/copper multilayer pattern was used as a laminate, and this pattern was transferred simultaneously with polyamide injection molding.

The base film was peeled off to obtain a mold structure with a metal pattern formed on the surface. This was used as a printed circuit and electrical components were mounted on it.

(Effects of the Invention) According to the present invention, it is possible to provide a high-quality metal pattern with good productivity to a mold structure having an arbitrary shape at the same time as the mold structure is molded.

The metal pattern printed structure 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. FIG. 2 is a sectional view showing an example of molding according to the present invention. DESCRIPTION OF SYMBOLS 1... Substrate, 2... Release layer, 3... Conductive film, 4
...Mask pattern, 5...Conductive pattern, 6
... Metal pattern, 7... Mold, 8... Supply passage, 9... Hole. Agent Patent Attorney Toshio Nishizawa No. 1
figure

Claims (1)

[Claims] (1) A conductive film is provided on the surface of the substrate, a mask pattern is formed, etching is performed, and after the mask is removed, the metal pattern obtained by electrolytic or electroless plating is transferred onto the surface of the molded body at the same time as molding. A mold pattern forming method.