JPH0357565B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a push switch that is often used for inputting operations on keyboards, video tape recorders, and the like.

(Conventional configuration and its problems) An example of a conventional push switch is shown in the first example.
As shown in the figure. In the figure, 1 is a circular recess 1 on the top side.
The contact terminals 2a and 3a are insert-molded so that the contact portions are respectively located on the bottom surface of the recess. It is taken out to the outside and constitutes terminals 2b and 3b. Reference numeral 4 denotes a push spring in the form of a disk having a reversing function and curved upward, which is housed in the recess 1a of the mounting base 1.Due to its shape, the push spring 4 is always in contact with the contact terminal 2a. It is configured so that it does not normally come into contact with the other. Reference numeral 5 denotes a circular push plate, and a protrusion 5a provided at the center of the lower surface lightly presses against the upper surface of the push spring 4 to prevent play, and the upper surface has a protrusion 5b for pressing against during operation. . Further, when the push plate 5 is pushed, it is housed in the recess 1a of the mounting base 1 with a slight wobble so that it moves downward against the pressure of the push spring 4, and the push plate 5 is housed in the recess 1a of the mounting base 1. Mounting base 1 with dowel 1b
It is held by a cover plate 6 fixed to.
In the normal state, the push spring 4 is in contact with only one of the contact terminals 2a and 3a.
When the push plate 5 is lightly pressed against the biasing force of the push spring 4, the push spring 4 comes into contact with both contact terminals 2a and 3a and the switch is turned on. When the force applied to the push plate 5 is released, the switch is turned on. is turned off again.

Now, when mounting and soldering the above-mentioned switch on a printed circuit board, it is necessary to immerse the terminals 2b and 3b in solder flux liquid. When lowering the height of a push-button switch, flux may enter the interior through the gap between the cover plate and the push-button plate, or dirt, dust, scraps from the push-button switch, etc. may enter the interior during operation. Various efforts have been made to improve the problem of poor contact at the contact points. Furthermore, in recent years, in addition to the demand for smaller size and thinner products, there has also been a demand for reflow soldering of push-type switches or the development of push-type switches that can withstand immersion in solder due to mounting methods. There was no Switch that could meet these market demands.

(Objective of the Invention) The present invention solves the problems in the conventional examples and also provides a highly reliable push switch without complicating the configuration in order to meet future market demands. It is something to do.

(Structure of the Invention) The push-type switch of the present invention includes a mounting base made of a heat-resistant insulator in which a contact terminal forming a conductive circuit is provided in a recess provided on the upper surface side, and a mounting base that is housed and held in the recess of the mounting base. It is equipped with a curved push spring with a reversing function, and a flexible heat-resistant film fixed to the top surface of the mounting base to completely cover the opening of the mounting base, and the heat-resistant film is attached using an outsert method. It is configured with a push button.

(Description of Examples) Examples of the present invention will be described below with reference to the drawings.

An embodiment of the present invention is shown in FIGS. 2 and 3,
Reference numeral 1 denotes a mounting base made of a heat-resistant insulator, which has a recessed part on the upper surface side, and conductive circuits 2a and 3a are embedded in the recessed part by inserts, and the contact terminals 2a,
A part of 3a goes outside of the mounting base 1 and connects to terminals 2b and 3.
b. Reference numeral 4 denotes a curved push spring having a reversing function, and is housed in the recess of the mounting base 1. Here, 7 is a flexible heat-resistant film, such as a polyimide film, which is attached to the upper surface of the opening of the mount using an adhesive or the like. In addition, this heat-resistant film 7 is extended and glued to the side wall of the mounting base 1,
The adhesion strength of the film may also be improved.

Further, the button 9 is formed by an outsert method using a heat-resistant resin into a through hole 7a previously provided in the center of the heat-resistant film, and a push spring push button 9a and a push button 9 are formed on the bottom and top sides, respectively.
b.

(Effects of the Invention) As described above, according to the embodiments of the present invention, it is possible to create a dust-proof semi-sealed structure without complicating the structure, and it prevents dust and dirt from entering, which is the worst thing for a switch to do during use. Furthermore, by using a heat-resistant resin or a heat-resistant film, there is no penetration of flux or molten solder, and a solder immersion solder mounting method, which was previously unthinkable, becomes possible. In addition, there is no need to provide dowel protrusions on the mounting base using the conventional caulking method, and by replacing the top surface of the push-type switch with a thin, flexible film, the shape of the push-type switch can be improved without reducing reliability. This makes it possible to reduce the size to the utmost limit, which is even more effective in making the device lighter, thinner, and smaller. Furthermore, since the button is integrated into the heat-resistant film using the outsert method, a thin push switch can be achieved without increasing the number of assembly steps.

In addition, in this explanation, the electrode terminal is illustrated in the horizontal direction, and the shape is also explained only in a cross-sectional view, but the present invention is applicable to the terminal shape and the external shape of the push switch (round, square, etc.). It is self-evident that it is effective regardless.

[Brief explanation of drawings]

Fig. 1 is a sectional view of a conventional general push switch, Fig. 2 is a sectional view of a push switch according to an embodiment of the present invention, and Fig. 3 is a sectional view of a push switch according to an embodiment of the present invention. It is a sectional view of the button part formed by inserting. 1...Mounting base, 2a, 3a...Contact terminal, 2b, 3
b...terminal, 4...push spring, 7...heat resistant film, 9...button, 9a...push spring push button, 9b...push button.

Claims (1)

[Claims] 1. A mounting base made of a heat-resistant insulator and provided with a plurality of contact terminals so that the contact parts constituting at least one pair of conductor circuits are arranged in the recess provided on the upper surface side, and The heat resistant film includes a curved push spring that is stored and held and has a reversing function, and a flexible heat-resistant film that is fixed on the mounting base so as to completely cover the opening of the recessed part of the mounting base. A push-type switch characterized in that a push button is formed on one side of a film and a push spring push button is formed on the other side by outsert molding of the same resin.