JPH0363831B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to a flexible wiring board that can be widely used in electrical equipment.

Conventional Structures and Their Problems In recent years, flexible wiring boards have been widely used for the purpose of reducing the size and weight of electrical equipment and streamlining the equipment assembly process. These flexible wiring boards are often used by electrically connecting conductors of other electric circuits, and are also often used simply as connecting wires to connect conductors of electric circuits to each other. .

Hereinafter, a method for connecting electric circuit conductors using a conventional flexible wiring board will be described with reference to the drawings.

FIG. 1 is a perspective view showing an example of the most common electrical circuit conductor connection method using a conventional flexible wiring board. A device 5 is mounted and connected, and a flexible wiring board 1 lined with a rigid insulating plate 3 is inserted into this connector device to facilitate insertion, and the metal piece conductor of the connector device and the flexible wiring board are inserted. This is a method of electrically connecting the wires by bringing them into contact with the wiring conductors. In this case, the metal piece and the wiring conductor are plated with a precious metal in order to stabilize the electrical connection at the contact portion. This method has the disadvantage that it requires a connector device, resulting in extremely high costs, and at the same time, there is a manufacturing limit to the spacing between the metal strip conductors of the connector device, making miniaturization difficult.

FIGS. 2 and 3 are perspective views and cross-sectional views showing another conventional method for connecting electric circuit conductors using a flexible wiring board, in which an insulating film 11
Conductors 12 and 16 are placed facing each other and electrically connected through solder connection portions 17. Solder connection in this method is performed by remelting the solder by heating and pressurizing preliminary solder or solder paste that has been previously formed on the wiring conductor.
However, in this connection method, the solder is remelted by indirect heating through the insulating film, which can damage the insulating film, make it difficult to align the wiring conductors with each other in fine wiring, and pressurize the welding solder. This had many problems, including the risk of short circuiting with adjacent wiring conductors.

OBJECTS OF THE INVENTION An object of the present invention is to provide a flexible wiring board that allows easy connection of electric circuit conductors and miniaturization of the connecting portion, and a method of connecting circuit conductors using the flexible wiring board.

Configuration of the Invention The flexible wiring board of the present invention is configured to have a spring material that generates elasticity in a direction perpendicular to the wiring conductors arranged in parallel in the connection terminal portion. As a result, when the flexible wiring board is inserted into the rigid wiring board, the wiring conductors arranged in parallel on the flexible wiring board and the circuit conductors on the rigid wiring board are in close contact with each other due to the spring material, and the soldering Since solder connection can be reliably performed by dipping into a bath, it is easy to connect electric circuit conductors and it is possible to miniaturize the connecting portion.

DESCRIPTION OF EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings.

4 and 5 are perspective views of a flexible wiring board in one embodiment of the present invention. In FIG. 4, 21 is an insulating film, 22 is a wiring conductor of connecting terminal portions arranged in parallel, and 23 is a plate spring material molded from a heat-resistant resin. The insulating film 21 on the opposite side of the wiring conductor 22 of the connection terminal portion and the leaf spring material 23 were bonded together with a heat-resistant adhesive to obtain the state shown in FIG. 5. FIG. 5 shows the completed state of the flexible wiring board of this example.

The flexible wiring board of this embodiment constructed as described above has a structure in which the plate spring material provides elasticity in the direction perpendicular to the wiring conductors arranged in parallel in the connection terminal portion. The leaf spring material 23 is placed on the insulating film 21 from the side without the wiring conductor 22,
Further, it has a structure in which the longitudinal dimension is longer than the insulating film 21, and is provided with a slit to prevent excessive insertion into the slit hole, which will be described later, and a burr to prevent it from falling off after insertion.

6, 7, and 8 are a perspective view and a sectional view of a method for connecting electric circuit conductors using the above-described flexible wiring board of the present invention. 6, 7, and 8, 24 is a rigid insulating substrate, 25 is a slit hole provided in the rigid insulating substrate, and 26 is a circuit conductor formed on the rigid insulating substrate. What is included is a rigid wiring board.

In the state shown in FIG. 6, the connection terminal portion of the flexible wiring board of this embodiment is inserted into the slit hole of the rigid wiring board in which the circuit conductor is formed up to the end of the slit hole. . FIG. 7 is a cross-sectional view of the inserted state, and the wiring conductors 22 arranged in parallel on the flexible wiring board and the circuit conductors 26 on the rigid wiring board are in extremely close contact due to the elasticity of the leaf spring material 23. becomes. Next, soldering is performed at the same time as other electric circuit components using a common soldering method, ie, immersion in a solder bath. FIG. 8 is a cross-sectional view of a state in which the wiring conductors 21 of the flexible wiring board and the circuit conductors 26 of the rigid wiring board are connected by solder connection portions 27, which are arranged in parallel by soldering. 7th
As shown in the figure, the wiring conductor 22 of the flexible wiring board and the circuit conductor 26 of the rigid wiring board were immersed in the solder bath while being in good contact with each other, so that a reliable solder connection was obtained. In addition, various studies were conducted regarding the parallel arrangement spacing of the wiring conductors on the flexible wiring board and the circuit conductors on the rigid wiring board, and the conductor spacing was 0.3 mm in conductor width.
Good results were obtained with no short circuits at 0.3 mm or more.

In the above embodiment, a heat-resistant resin molded product was used as the leaf spring material, but a material having heat resistance and elasticity, such as metal, can be used. Moreover, although the flexible wiring board is configured on only one side of the leaf spring material, it can be configured on both sides.

Effects of the Invention As is clear from the above description, the flexible wiring board of the present invention has a spring material that generates elasticity in the vertical direction with respect to the wiring conductors arranged in parallel in the connecting terminal portion, and the wiring conductors are attached to the insulating film. It is placed from the non-contact side, and its longitudinal dimension is longer than the insulating film, and its both ends are sharpened to prevent excessive insertion into the slit hole provided in the rigid wiring board, and to prevent it from falling off after insertion. Since it is equipped with a spring material with a burr, there is no need for special connection devices such as connectors, and electrical circuits can be easily connected by soldering at the same time as general electrical circuit components.
Moreover, since even fine wiring can be reliably connected, an excellent effect can be obtained in that the connecting portion can be made smaller. Furthermore, there is an advantage that flexible wiring boards can be formed on both sides of the leaf spring material.

[Brief explanation of drawings]

1, 2 and 3 are perspective views and sectional views of a conventional method of connecting electric circuit conductors using a flexible wiring board, and FIGS. 4 and 5 are an embodiment of the present invention, respectively. FIG. 6, FIG. 7, and FIG. 8 are a perspective view and a sectional view of a method for connecting electric circuit conductors using the flexible wiring board of the present invention. 1... Flexible wiring board, 3... Rigid insulating board, 4
... Rigid wiring board, 5 ... Connector device, 1
1, 21... Insulating film, 12, 22... Wiring conductor, 23... Leaf spring material, 14, 24... Rigid insulating substrate, 25... Slit hole, 16, 26...
...Circuit conductor of rigid wiring board, 17, 27...Solder connection part.

Claims (1)

[Claims] 1. An insulating film, a wiring conductor of a connecting terminal portion arranged in parallel to the insulating film, and a wiring conductor arranged on the insulating film from the side without the wiring conductor and having elasticity in a direction perpendicular to the wiring conductor. a spring material to be generated, the longitudinal dimension of the spring material is longer than the width of the insulating film, and both ends thereof are provided with sharp edges to prevent excessive insertion into a slit hole provided in a rigid wiring board, and after insertion. A flexible wiring board characterized by having a burr to prevent it from falling off.