JPH0331093Y2 - - Google Patents

Description

[Detailed description of the invention] [Field to which the invention pertains] The invention relates to electrical equipment such as video equipment such as magnetic recording cameras and silver halide cameras, electronic office equipment such as copying machines and computers, or communication equipment.・It has an electronic circuit, and the circuit is configured on a hard electric circuit wiring board (hereinafter referred to as a hard board) or a flexible electric circuit wiring board (hereinafter referred to as an FCB), and the circuit is The present invention relates to electrical packaging for incorporating into the electrical equipment.

[Prior art]

In a camera for a video tape recorder or a camera for silver halide, a photometric circuit, an exposure value calculation circuit, for driving the aperture, shutter, and lens of the camera's exposure control aperture mechanism, shutter mechanism, or lens mechanism;
Each circuit such as an autofocus circuit is required, and the transistors, resistors, capacitors, coils, ICs, LSIs (integrated circuits), etc. that make up each circuit are soldered onto the circuit pattern provided on the hard board or FCB. and fix it to form each circuit.

[Problems with conventional technology]

In the electrical packaging inside the camera mentioned above, as electric circuits become more complex due to the trend toward further electrical control of cameras and the sophistication of camera functions, the number of circuit boards inside the equipment increases to form circuits, and the equipment becomes more compact. There is an increasing need for electrical packaging to be arranged in a precise manner in order to make it easier to integrate and assemble equipment, as well as to improve the workability of replacing parts and units during breakdowns and repairs.

Due to its flexibility, FCBs can be placed in narrow spaces; however, soldering and fixing the aforementioned circuit components onto FCBs requires a certain amount of space; B
The circuit portion B3 that connects the exposure calculation circuit block B2 to the exposure calculation circuit block B2 is formed of an FCB, and the wiring of the FCB within the camera complicates the implementation.

The above-mentioned problem is not limited to cameras, but applies to electrical equipment in general.

[Issues of this invention]

This invention aims to solve the electrical mounting problems in the conventional electrical equipment mentioned above.
The proposed problem is to reduce the number of circuit boards such as circuit boards and make the mounting form simple and uncluttered.
A further object of the present invention is to wire a circuit pattern directly to the body, cover, or intermediate body fixed in the body of an electrical device as a method of reducing the number of circuit boards mentioned above. Circuit pattern B3 that connects circuit block B2
The proposed problem is to wire directly to the body, cover, or intermediate surface of the device, thereby reducing the portion of the circuit pattern B3 and making the mounting form neat.

Furthermore, the present invention provides a circuit pattern in which a circuit pattern is wired across adjacent surfaces of a resin molded body, and an integrated circuit IC of each of the aforementioned circuit blocks is arranged on each surface provided with the circuit pattern. We propose a suitable example.

[Means for achieving the above task]

A body or a cover of an electrical device including an electric circuit, or an intermediate body to be attached to the body/cover is molded from a resin material to form a resin molded body, and the ridge line portions of adjacent surfaces of the resin molded body are formed into an arc shape. The above object is achieved by forming a circuit pattern containing magnetic powder on the adjacent surfaces and the arc-shaped portion during molding of the resin molded product.

[Explanation of Examples]

Figure 1 shows the cover of an electrical device with an electric circuit.
A cross-sectional view of a part of a case, a body, or a resin molded product as an intermediate body is shown.

In the figure, 100 indicates a partial cross section of the molded product, and adjacent surfaces of the molded product 100 and surfaces 100
The ridge line portions 100C of A and 100B are curved surfaces with a certain curvature, and a circuit pattern 200 is formed continuously on the flat surfaces 100A and 100B and the curved surface 100C, and the circuit pattern 200 has the above-mentioned marks shown in FIG. circuit blocks B1 and B2 are arranged, and each block B1 and B2 is electrically connected by a circuit pattern 200.

FIG. 2 shows a sectional view of a main part of a molding apparatus for molding the resin molded product shown in FIG. 1, and FIG.
B, C, D, and E show explanatory diagrams of the molding operation.

FIG. 2 shows a magnetic circuit constructed by attaching a mold 4 and an excitation coil 3 to a molding machine. The mold 4 is composed of a movable mold plate 5 and a fixed mold plate 6, and the patterned parts on the surface of the cavity 7 are made of magnetic materials 5a and 6a such as carbon steel, and the parts other than the pattern are made of SUS303, for example. Non-magnetic materials such as 5
Consisting of b and 6b. Also, molding machine platen 1,
The molding machine tie bars 2 are each made of a magnetic material such as carbon steel. When the excitation coil 3 is energized, magnetic lines of force 12 are generated as shown by the arrows in the figure, generating magnetic force on the surface of the cavity 7 of the magnetic bodies 5a and 6a, and the magnetic powder 9 can be attracted and fixed to the cavity surface. .

In the mold structure shown in FIG. 2 above, the resin molded product 10
Template plates 5a and 6 that constitute the cavity 7 that forms 0
The corners 5a' and 6a' of a have their respective radii as shown in Figure 1.
The curved surface has a curvature of R ₁ and R ₂ . In particular, the relationship between the wall thickness t of the resin molded product 100 and the radii R ₁ and R ₂ is set to R ₂ −R ₁ =t, thereby achieving a more preferable result of the present invention. Furthermore, the flat part 1 of the resin molded product
A preferable result can be obtained by making the wall thicknesses of 00A and 100B the same as the wall thickness of the curved surface portion 100C.

Next, FIGS. 3AB to 3E show the manufacturing process of the embodiment of the present invention.

First, as shown in FIG. 3A, the movable mold plate 5 is opened, and the upper part of the cavity surface of the nonmagnetic material 5b is masked with the mask 8. That is, only the portion of the magnetic body 5a to which the magnetic powder 9 is to be attached is exposed on the cavity surface. The material of the mask 8 is, for example, metal, rubber, plastic, etc., and is fixed to the movable template 5 by suitable means.

Next, as shown in FIG. 3B, magnetic powder 9 is applied onto the exposed portion of the cavity surface and the surface of the mask 8 using the electrostatic coating machine 10. The magnetic powder 9 is a conductive ferromagnetic material containing a binder component, for example, 90% by weight of nickel powder with an average particle size of 2 to 3 μm and 10% by weight of acrylic resin powder as the binder component. In some cases, the binder components are heated to a molten state, mixed, and then cooled and pulverized to an average particle size of 30 μm. Here, as the nickel powder, Type 255 manufactured by Inc. Japan Branch can be used, and as the acrylic resin, Fine Dayc A224S manufactured by Dainippon Ink and Chemicals Co., Ltd. can be used. When the magnetic powder 8 is negatively charged with a voltage of -70KVolt by the electrostatic coating machine 10 and painted with the mold grounded, the electrostatic force between the mold and the powder causes the magnetic material 5a in the cavity and It adheres to the surface of the mask 8.

Next, when the mask 8 is removed from the movable mold plate 5, a pattern is formed by the magnetic powder 9 only on the surface of the cavity 7 of the magnetic body 5a, as shown in FIG. 3C.

Next, as shown in FIG. 3D, the mold 4 is closed and the excitation coil 3 is energized. As a result, a magnetic force is generated on the surface of the cavity 7 of the magnetic body 5a, and the already attached magnetic powder 9 is strongly attracted and fixed to be held on the cavity surface. After that, when a resin material is injected into the cavity, the magnetic powder 9 is fixed and held at a predetermined position in the cavity by magnetic force and electrostatic adsorption force, and the injected resin is filled so as to embed the magnetic powder. . Furthermore, at this time, the binder component such as acrylic resin contained in the magnetic powder 9 is melted and softened by the high temperature and high pressure of the injected resin 11, and the binder component is also solidified at the same time as the injected resin is cooled and solidified, and the binder and molded product resin are extremely It has strong adhesion.

After cooling the injected resin, the mold was opened and the molded product taken out is shown in FIG. 3E. The pattern formed by the magnetic powder 9 on the surface of the cavity 7 of the mold before molding is transferred to the surface of the molded product as a circuit pattern 13 so as to be embedded in the injection resin 11.

Here, for example, after applying a magnetomotive force of 346 coil windings (turns) and a current of 60 (amperes) to the excitation coil 3, polystyrene resin at 200°C was injected into the cavity at a pressure of 340 kg/cm ² from an injection cylinder. However, the magnetic powder was transferred to a predetermined position, and a molded article having a circuit pattern 200 with a surface resistance value of 1.0 Ω/□ was obtained.

By the above molding operation, the circuit pattern 200 can be formed simultaneously with the resin molded product 100.
Then, integrated circuits (ICs) of circuit blocks B1 and B2 shown in FIG. 4 are connected to each end of the circuit pattern 200.

[Other Examples]

Although the above embodiments have been explained using electrical circuits as an example, the present invention is not limited to this, and by changing the pattern shape of the magnetic material and the magnetic material, the surface of the molded product can be improved, such as decorative designs on the surface of the molded product. It can be applied to the production of heterogeneous resin molded products.

Further, the present invention is not limited to injection molding, and may be applied to methods such as RIM molding, LIM molding, and cast molding.

[Effect of idea]

As explained above, according to the present invention, magnetic powder is attached to the cavity surface of a mold made of a combination of magnetic and non-magnetic materials by electrostatic coating to form a pattern shape, and molding is performed using magnetic force. Therefore, it is possible to form a circuit on the uneven surface of a resin molded product at the same time as molding without secondary processing, and there is an effect that a circuit with excellent adhesion to the molded product can be formed.

In particular, the present invention arranges circuit blocks B1 and B2 on adjacent planes of a resin molded product.
By electrically connecting 1 and B2 with the circuit pattern 200 molded and wired at the same time as the resin molded product, the conventional flexible printed circuit board can be eliminated, and there are also advantages in the assembly work of electrical equipment.

Furthermore, this invention can be applied to adjacent surfaces (planes) of resin molded products.
By making the ridge line portions curved, it was possible to solve the problem of poor adsorption of magnetic powder in the ridge line portions, and improve the reliability of the wiring in the circuit pattern 200 portion.

In the present invention, the ridge line portion 100C of the adjacent surfaces 100A and 100B of the resin molded product 100 is a curved surface, but the ridge line portion 100 is curved as shown in FIG. 5 to form a slope portion 100'C. It can also be configured as follows.

[Brief explanation of drawings]

FIG. 1 is a partial sectional view of a resin molded product according to the present invention. Figure 2 is a cross-sectional view of the mold. FIGS. 3A to 3E are explanatory diagrams of the molding operation. FIG. 4 is an explanatory diagram of the circuit configuration. FIG. 5 is a partial sectional view of a resin molded product according to another example. 1... Molding machine platen, 2... Molding machine tie bar, 3... Excitation coil, 4... Mold, 5... Movable side template, 6... Fixed side template, 5a, 6a... Magnetic material, 5b, 6b...Nonmagnetic material.

Claims (1)

[Claims for Utility Model Registration] An electrical device formed by providing a continuous circuit pattern on the two planes of a resin molded body having at least two adjacent planes to form a body, a cover, or an intermediate body attached to the body or cover. The ridgeline portions of the adjacent surfaces are curved surfaces, and the cavity surface of the molding die is composed of a magnetic material and a non-magnetic material, and conductive magnetic powder is applied to the magnetic material by the magnetic force of the magnetic material. A resin molded body is formed by adsorbing and holding a resin material and injecting a resin material to create a continuous circuit pattern of conductive magnetic powder on the two flat surfaces and a curved surface, and an electric component is attached to each of the flat surfaces to form the circuit pattern and the electric component. An electrical device comprising an electrical circuit formed by.