JPH0473685B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Field to which the invention pertains] The present invention relates to a molded product having a conductive pattern in which a circuit pattern such as electrical wiring is molded together with the molded product, and a method for molding the same.

[Prior art to the invention]

Conventional methods for forming circuits on the surface of resin molded products include providing concave lines on the molded product and applying partial electrolytic plating there, or inserting a film with a circuit pattern formed on it into a mold. There is a method of transferring a circuit pattern from a film to a molded product at the same time as molding.

In addition, as a method of forming a conductive film on the surface of a resin molded product, a powdered resin composition containing a high concentration of conductive fine powder is applied into a mold by electrostatic coating, and then the resin molded product is molded. Method (Unexamined Japanese Patent Publication No. 1983-
111335).

[Problem that the invention is trying to solve]

However, the method of providing concave lines on the molded product cannot be applied to three-dimensional shapes, and furthermore, the process becomes complicated because the molded product is subjected to a plating process as a secondary process. Furthermore, the method using a film has limitations in its ability to handle deeply drawn shapes and three-dimensional shapes due to problems such as the film being torn or the wiring being cut. In the method disclosed in JP-A No. 61-111355, the ratio of conductive fine powder contained in the powdered resin composition is large, and the resin component is small, resulting in insufficient strength of the film, and the pressure of injection resin may cause the film to shift or crack. This resulted in the drawback that it lacked reliability as a conductive film.

[Problem to be solved by the invention]

The present invention solves the weak points in the strength of the circuit pattern portion produced by the circuit pattern forming method using plating or the circuit pattern transfer method described above, and further provides a molded product having a circuit pattern that is sufficiently satisfactory for current conduction as a circuit pattern. do.

Furthermore, the present invention provides a circuit pattern that allows electrical components such as integrated circuits to be mounted on molded products made of resin materials, such as the main body of an electronic desktop calculator (hereinafter referred to as a calculator), the main body of a camera, a cover, etc. We propose a molded article and a method for manufacturing the molded article.

[Means for achieving the aforementioned tasks]

In order to achieve the above-mentioned object, the present invention provides a mold for molding a molded article, for example, the body or cover of a device on which electric parts such as the aforementioned calculator or camera are mounted. When molding a molded product using the mold, the conductor pattern is molded through the following steps.

First, the cavity surface of the mold is masked using a mask, and a circuit pattern composition containing a conductive material is applied to the exposed surface of the cavity surface.

Next, in order to protect the circuit pattern portion of the conductive material, a pattern holding composition is applied over the conductor pattern.

When the mask is then removed, the circuit pattern portion adheres to the mold surface, and the pattern holding composition is formed to cover the circuit pattern portion.

Following removal of the mask, a molding resin material is injected into the cavity of the mold to mold the main body and cover of the device.

According to the present invention, a molded product having a conductive pattern is formed through the above steps.

[Description of embodiments of the invention]

Examples will be described in detail below with reference to the figures.

FIGS. 1A and 1B show a perspective view and a cross-sectional view of a molded product according to the present invention, which is a case/cover for an electric appliance such as the aforementioned calculator. The case 1 has a plane part 1A and side views 1B, 1B, and is entirely made of plastic resin polycarbonate by injection molding. Case 1
A plane part 1A and conductor patterns 1c, 1c, .
A conductor pattern holding resin portion 1D is arranged so as to surround c, 1c, .

Next, the manufacturing method will be described in detail with reference to FIG. 2 and subsequent figures.

In Fig. 2, 2A is the movable mold plate of the mold, 2B
indicates the fixed side template of the mold, and each template 2A, 2B
A molding cavity is formed on the mating surfaces.

The movable mold plate 2A is opened and closed by a drive means (not shown) to open and close the mold.

A molten resin injection cylinder (not shown) is connected to the stationary template 2B, and the resin from the injection cylinder is injected into the cavity through the sprue 2b.

Next, the process will be explained step by step.

() Conductive pattern attachment process.

First, the movable template 2A is opened, and a mask 4 made of insulating rubber that covers the area other than the part that will become the conductive pattern is fixed to the cavity surface of the movable template 2A. Exposed surface 4a (non-mask part) of the mask 4
is formed into a shape in which a conductive pattern is formed. After fixing the mask, a composition for forming a conductive pattern is applied, and this application is carried out as follows.

In the adhesion operation, a powder composition containing a conductive material is kneaded and put into a coating gun indicated by reference numeral 6 in FIG. 3, and then sprayed onto the first mask 4 in the manner of spray painting. The conductive pattern portions 1c, 1c...
The powder composition is prepared by heating and melting metal powder such as nickel as a conductive material and thermoplastic resin such as acrylic resin, kneading, cooling, and pulverizing into powder.

In this example, the conductive material is nickel powder type 255 manufactured by Inc.
90% and Mitsui Toatsu Chemical Co., Ltd. as a thermoplastic resin.
A powder composition containing 10% by weight of Aromatex AP-1648, an acrylic resin, and having an average particle size of 10 μm was placed in the coating gun 6 and used.

The coating gun 6 is configured to be movable toward the center of the molds 2A and 2B so that the spray port faces the cavity surface to which the first mask 4 is attached after the mold is opened, or the mold is opened manually. The mask is inserted into a mold, and the powder composition is sprayed onto the exposed cavity surface of the mask.

The movable side template 2A is made of metal material and connected to ground. The powder composition in the coating gun is sprayed at a spraying pressure of 1 to 2 kg/cm ² . Since the mold 2A is grounded, set it to 0 volts, and set the spray port of the electrostatic coating gun 6 to a voltage of approximately -70Kv relative to the mold 2A, so that the ejected powder will be approximately -70Kv relative to the mold.
to be charged. When the powder is sprayed onto the cavity surface under these conditions, the powder composition adheres to the cavity exposed surface and the mask as shown in Figure 3, and the powder composition is electrostatically charged to the mold due to negative charge. Conductive pattern parts 1c, 1c while maintaining the adsorbed state
...is formed.

() Step of attaching resin for holding the conductive pattern After applying the conductive pattern portion, the resin part 1D for holding the pattern is formed using the paint gun 6. As the material for the resin part 1D, Mitsui Toatsu Chemical Co., Ltd. Aromatex AP made of acrylic resin manufactured by Co., Ltd.
-1648 with an average particle size of 10 μm is placed in the gun.

The coating conditions are the same as above, and the powder is 1000kg/
Spray at a pressure of cm ² from above the mask as shown in Figure 4. By this spraying, the powder further coats the protective resin on the tops of the conductor patterns 1c, 1c, . . . which were formed by the previous spraying.

() Molding process After spraying the pattern holding resin parts 1D, 1D..., the mask is removed, the mold is closed, and the case body is molded.

Molding is carried out by injecting polycarbonate resin at 300℃ from an injection cylinder (not shown) at a pressure of 1000Kg/ ^cm2 .
This is done by injecting into the mold cavity as shown in the figure.

After injection molding, the mold undergoes a cooling process, the mold is opened, and the molded product 1 is taken out.

The molded product 1 is molded as shown in FIGS. 1A and 1B, and has conductor pattern parts 1c and 1c on its inner surface.
... are exposed, and between the conductor pattern parts 1c, 1c... and the molded product body, the conductor pattern parts 1c, 1c... are exposed.
The pattern holding resin part 1D is positioned so as to surround the...

〔Effect of the invention〕

According to the present invention, after molding the conductive pattern, when molding the molded product main body portion 1 with a molding resin material, the conductive patterns 1C, 1C... are protected by the pattern holding part 1D and are injected. It was possible to prevent the molding resin material from coming into direct contact with the conductor pattern, and it was possible to prevent the conductor pattern from peeling off or shifting due to injection pressure.

[Brief explanation of drawings]

FIG. 1A is a perspective view of a molded product according to the present invention;
Figure B is a sectional view taken along the line A-A in Figure 1, Figure 2 is a diagram showing the state in which the mold opening and the first mask are fixed, Figure 3 is an explanatory diagram of the process of spraying the conductor pattern section 1D, and Figure 4 is the first FIG. 5 shows a state in which the mask is removed and a second mask is applied, and FIG. 5 shows a state in which holding resin is sprayed. 2A, 2B... Mold, 4, 6... First and second masks, 4, 7... First and second masks.

Claims (1)

[Scope of Claims] 1. A molded article formed by molding a resin material for molding, comprising a conductive pattern made of a first resin material containing a conductive material and exposed on the surface of the molded article; A pattern holder having a holding resin material between the conductive pattern and the conductive pattern, for preventing injection of the molding resin material, particularly direct contact between the molding resin material and the conductive pattern. A resin molded product consisting of parts. 2. In a method for molding a resin molded product having a conductive pattern, () a masking step of applying a mask to the mold cavity surface excluding the conductive pattern portion, and () applying a resin composition containing a conductive material to the non-masked portion of the mask. () a second coating step of applying a conductive pattern holding resin material onto the conductive pattern portion;
and () a step of injecting a molded article molding resin into a mold cavity after the second application step and molding the resin molded article.