JPH07183672A - Electrical appliance and manufacture therefor - Google Patents

Abstract

PURPOSE:To support further downsizing of electrical appliances by employing a concept different from conventional ones for mounting electrical components. CONSTITUTION:A printed circuit 4 is directly formed on an internal face of a container 1 which also serves as an outer case or the like of a product and has three-dimensional internal faces, and electrical components are mounted on the printed circuit 4. The container which is injection-molded is preferably employed, wherein the printed circuit 4 is formed at the same time as molding of the container 1 by locking a patterned copper foil or the like no a metal mold in advance.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electric product in which electric parts are mounted. In the present application, “electrical product” is a concept that includes all products that have some kind of electric circuit and are equipped with electric parts. Therefore, for example, a product such as a camera which is not included in the "electrical product" in a general sense may be targeted.

[0002]

BACKGROUND OF THE INVENTION Many electrical appliances currently on the market
A structure has been adopted in which electric parts (including electronic parts such as integrated circuits, the same applies hereinafter) are mounted on a printed circuit printed on a substrate. FIG. 3 is an explanatory diagram of a mounting structure of an electric component in such a conventional electric product. The electric product shown in FIG. 3 is a type often found in various home appliances, and includes a container 1 having a three-dimensional inner surface, and a printed circuit board 2 on which electric components are mounted and fixed to the inner surface of the container. It is equipped with.

The container 1 is often made of plastic formed by injection molding or the like, and as shown in FIG. 3, two containers 1 are combined to form an internal space, and various mechanisms are provided in the internal space. Are placed. Then, the printed circuit board 2 on which the electric component 3 is mounted is fixed to the inner surface of the container 1 or the like and disposed inside the container 1. Printed circuit board 2
Is a printed circuit formed on a substrate such as a plastic board or a resin film, and the printed circuit is formed by a method such as photo etching or printing.

[0004]

There are various electric appliances to which the present invention is applied, but one common tendency is miniaturization and high functionality. Here, the miniaturization and the high functionality bring about the complexity of the mechanism arranged inside the container. That is, electric mechanisms such as a printed circuit board and various mechanical mechanisms must be compactly put together in a container. In terms of the printed circuit board, recently, high-density mounting technology has been actively developed and many electric components can be mounted on a single board. Then, by using a substrate such as a flexible film, a printed circuit board is arranged in a narrow space in the container to make it further compact.

However, the compacting in this way has reached a limit in a sense, and in order to achieve the further compacting while having the necessary functions, the problem is solved by a different idea from the conventional one. There is a need to. The present invention has been made in order to solve such a problem, and an object of the present invention is to cope with further downsizing of electric products by adopting a different idea from the conventional method for mounting electric parts. .

[0006]

In order to achieve the above object, the invention as set forth in claim 1 of the present application is an electric product provided with a container having a three-dimensional inner surface. A printed circuit is formed, and electrical components are directly attached to the container along the printed circuit. In order to achieve the above-mentioned object, the invention according to claim 2 of the present application is the method of manufacturing an electric product, wherein a printed circuit is formed on the inner surface of a container having a three-dimensional inner surface. Along with the step of directly attaching the electric component to the container. In order to achieve the above-mentioned object, the invention according to claim 3 of the present application is the electrical product according to claim 1 or the manufacturing method according to claim 2, in which the container is formed by injection molding. The printed circuit is formed on the inner surface of the container simultaneously with the molding of the container. In order to achieve the above-mentioned object, the invention according to claim 4 of the present application is the electrical product according to claim 1 or the manufacturing method according to claim 2, wherein the container is an outer case of the electrical product. It also has a configuration that doubles as.

[0007]

EXAMPLES Examples of the present invention will be described below. Figure 1
FIG. 3 is a schematic explanatory diagram of an electric product according to an embodiment of the present invention.
The electric product shown in FIG. 1 has an internal space formed by combining two three-dimensional containers 1 as in the conventional one shown in FIG. 2, and various mechanisms are arranged in the internal space.

The container 1 is usually made of an insulating material such as plastic and is molded by a method such as injection molding. Then, as shown in FIG. 1, the three-dimensional inner surface of the container 1 is
The printed circuit 4 is formed, and the printed circuit 4
The electric component 3 is directly attached to the inner surface of the container 1 along the line. That is, the electric product shown in FIG. 1 does not use the conventional printed circuit board 2 but mounts the electric component 3 directly on the inner surface of the container 1. The mounting is performed by a soldering method using cream solder or the like.

Hereinafter, the description corresponding to claim 2 will also serve as
A method of forming the printed circuit 4 will be described. A preferred example of the method of forming the printed circuit 4 is a case where the container 1 is formed by injection molding, and the circuit is formed simultaneously with the molding. First, a copper foil having an adhesive attached to one surface is formed into a desired circuit pattern by a method such as chemical etching or mechanical die cutting.

The copper foil thus formed is set on the inner surface of the mold of the injection molding machine. At this time, the surface to which the adhesive is attached is exposed to the surface. In addition, "set" means
It means that it is locked to the inner surface of the mold in a detachable state after molding. For example, a magnet is arranged to lock by magnetic force, static electricity is locked, or something is locked on the inner surface of the mold. This can be achieved by providing a part and locking it. Of course, if it can be locked only by gravity, that may be sufficient. In this way, the resin is poured into the mold in which the copper foil is locked on the inner surface to mold the container 1 having a predetermined shape. As described above, since the surface of the copper foil to which the adhesive is adhered is exposed, the printed circuit 4 is automatically adhered to the surface of the molded container 1, and when the printed circuit 4 is ejected from the molding machine, it is already in a predetermined shape. The printed circuit 4 having the pattern is formed.

The electric component 3 is directly mounted on the inner surface of the container 1 molded with the printed circuit 4 thus formed. For example, cream solder is put on a predetermined portion on the printed circuit 4 by a screen printing method, and then the electric component 3 is mounted by a robot arm or the like. Then, the container 1 is introduced into an infrared furnace or the like to reflow the solder,
After that, if it is cooled and solidified, the mounting is completed. It is obvious that the surface mounting technique, which has been widely used recently, that is, the technique of mounting the electric component 3 on only one side surface of the substrate, can be preferably applied to the mounting of this embodiment.

In the above description, it is possible to form the printed circuit 4 without attaching the adhesive to the copper foil. FIG. 2 is a partial cross-sectional view illustrating an example in which an adhesive is not used. In this embodiment, an opening 50 for fixing is provided in the copper foil 5, and the resin 6 is projected and filled into the opening 50 so that the copper foil 5 is fixed to the container 1. Note that, as shown in FIG. 2, it is more effective in terms of fixing strength if the size of the opening 50 is gradually increased in accordance with the direction in which the resin is filled.

The method of placing solder on the printed circuit 4 may be a transfer method. That is, it is a method in which cream solder is printed in a desired pattern on a predetermined pad and the pad is pressed and transferred to the inner surface of the container 1 after molding. This transfer method is advantageous when the inner surface of the container 1 is a curved surface or when the container 1 is small.

In the above embodiment, the printed circuit 4 is formed at the same time when the container 1 is formed.
The present invention is not limited to this. It is also possible to carry out by a method of pasting the copper foil on the inner surface of the container 1 with an adhesive after molding the container 1. In this case, the copper foil may be adhered after the solder is placed on the copper foil. In addition, other conductive materials than "copper" can of course be adopted, and wire-like ones other than "foil", that is, a thin sheet-like one can also be adopted.

The electric appliances of this embodiment described above include, for example, cooking electric appliances such as electric rice cookers and electric mixers, and various electric appliances such as electric razors and telephones. In such electric products, the container 1 described above is often an outer case of the product. For example, when products are made compact, the storage member often consists of only one container 1. In such a case, the electric component 3 is mounted on the inner surface of the one container 1 as described above,
This container 1 is called an "outer case". In such a case, the effect of the present invention is most exerted. still,
“Outer case” means a “case” whose outer surface is also the outer surface of the product.

[0016]

As described above, according to the method for manufacturing an electric product according to claim 1 or claim 2 of the present application,
Since there is no need to arrange a printed circuit board in the container, the electric product becomes more compact. At the same time, this leads to both the cost reduction due to the reduction of the number of parts and the cost reduction due to the process reduction. According to the third aspect of the invention, the printed circuit is formed at the same time when the container is formed, so that the number of steps can be further reduced. Further, according to the configuration of the fourth aspect, the effect of the present invention, that is, compactness, is most exerted.

[Brief description of drawings]

FIG. 1 is a schematic explanatory diagram of an electric product according to an embodiment of the present invention.

FIG. 2 is a partial cross-sectional view illustrating an example when an adhesive is not used.

FIG. 3 is an explanatory view of a mounting structure of an electric component in a conventional electric product.

[Explanation of symbols]

 1 Container 3 Electrical Parts 4 Printed Circuit

Claims (4)

[Claims] 1. An electric product provided with a container having a three-dimensional inner surface, wherein a printed circuit is formed on the three-dimensional inner surface, and an electric component is directly attached to the container along the printed circuit. An electrical product characterized by being 2. A method of manufacturing an electric product, comprising the steps of forming a printed circuit on an inner surface of a container having a three-dimensional inner surface and directly mounting an electric component on the container along the printed circuit. Method. 3. The electric product according to claim 1, wherein the container is formed by injection molding, and the printed circuit is formed on the inner surface of the container at the same time when the container is molded. Alternatively, the method for manufacturing an electric product according to claim 2. 4. The method of manufacturing an electric product according to claim 1, wherein the container also serves as an outer case of the electric product.