JPS6182625A - Push type switch - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

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

(Constitution of conventional example and its problems) An example of a conventional push-type switch is shown in FIG. In the figure, reference numeral 1 denotes a mounting base made of an insulator having a circular recess 1a on the upper surface side, and contact terminals 2a are arranged so that the contact portions are respectively located on the bottom surface of the recess.

3a is insert molded, and this contact terminal 2a.

3a has both ends taken out from the mounting base 1 and terminal 2b.
, 3b. Reference numeral 4 denotes a circular push spring having a reversing function, which is housed in the recess 1a of the mounting base 1 and has a reversible function on the upper side, and due to its shape, the push spring 4 is always in contact with the contact terminal 2a. The configuration is such that one does not normally come into contact with the other. 5 is a circular push plate, with a protrusion 5a provided at the center of the lower surface side.
is lightly pressed against the upper surface of the Pnosh spring 4 to prevent play, and there is a protrusion 5b on the upper surface to be pressed 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.
It is held by a cover plate 6 that is fixed to the mounting base 1 by caulking dowels 1b provided in the mount 1. 1 In the normal state, the push spring 4 connects 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 contacts both contact terminals 2a and 3a, and the switch is turned ON, and the push plate When the force applied to 5 is released, the switch will turn 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 the height of a push-type switch is lowered, flux may enter the interior through the gap between the cover plate and the push plate, and dirt, dust, and scraps from the push plate may enter the interior during operation, causing damage to the contact area. Various efforts have been made to improve this problem, as it may cause poor contact. 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 solder immersion due to mounting methods. There was no type switch that could meet these market demands.

(Objective of the Invention) The present invention solves the problems of 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 contact terminals constituting a conductive circuit are 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 consists of a curved push spring with a reversing function, and a flexible heat-resistant film on the top surface of the mount to completely cover the opening of the mount. The push button is constructed using the outsert construction method, adhesive method, or the like.

(Explanation of Examples) Hereinafter, the present invention will be explained in detail with reference to the drawings.

An embodiment of the present invention is shown in FIGS. 2 and 3.

1 has a concave portion on the upper surface side; 5 has a conductive circuit 2a in the concave portion;
, 3a is a mounting base made of a heat-resistant insulator buried by an insert, and a portion of the contact terminals 2a, 3a protrudes outside the mounting base 1 to become terminals 2b, 3b.

4 is a curved push spring having a reversing function, which is housed in the recess of the mounting base 1; 7 is a flexible heat-resistant film, such as a polyimide film. , which is attached to the upper surface of the opening of the mounting base using adhesive or the like. In FIG. 3, a push button 8 is provided on the lower surface side of the heat-resistant film 7 using an adhesive method, and furthermore, the heat-resistant film is attached to the side wall of the mounting base 1. This is an example where the strength of the film is improved by adhesion.

FIG. 4 shows button portions 9a and 9 on the bottom and top sides of the heat-resistant film, respectively, where a through hole 7a is provided in the center of the heat-resistant film and a heat-resistant resin is applied using an outsert method or the like.
FIG. 5 shows a push-type switch constructed using the heat-resistant film.

(Effects of the Invention) According to the first embodiment of the present invention, it is possible to have a dust-proof semi-sealed structure without complicating the structure, and when used as a switch, it is possible to prevent the intrusion of dust and dirt, which even mulberry plants dislike. Further, by using a heat-resistant resin and a heat-resistant film, there is no penetration of flux or molten solder, and a solder immersion soldering 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.

In this explanation, the electrode terminals are illustrated in the horizontal direction, and the shapes are explained only in cross-sectional views.
Terminal shape, external shape of push switch (round, square, etc.)
It is obvious that it is effective regardless of the situation.

[Brief explanation of drawings]

FIG. 1 is a cross-sectional view of a conventional general push-type switch, FIGS. 2, 3, and 5 are cross-sectional views of a push-type switch according to an embodiment of the present invention, and FIG. 4 is a cross-sectional view of a push-type switch according to an embodiment of the present invention. FIG. 3 shows a cross-sectional view of a part with resin outsert in a film according to an example. 1...Mounting base, 2a, 3a-contact terminal, 2b, 3b
... terminal, 4 ... push spring, 5 ...
Push plate, 6... Cover plate, 7... Heat resistant film, 8... Push button. Patent applicant Matsushita Electric Industrial Co., Ltd. Figure 2 Figure 3 Figure 4 Figure 5

Claims (3)

[Claims] (1) A mounting base made of a heat-resistant insulator and provided with a plurality of contact terminals so that contact parts constituting at least one pair of conductor circuits are arranged in a recess provided on the upper surface side, and a recess in the mounting base. The push spring has a curved shape and has a reversing function and is housed and held within the mount, and a flexible heat-resistant film is fixed on the mount so as to completely cover the opening of the mount recess. push switch. (2) A push button is formed on one side of the heat-resistant film, and a push plate push button is formed on the other side by outsert molding of the same resin.
Push-type switch described in section 1). (3) The push-type switch according to claim (1), characterized in that a button made of resin, metal piece, etc. is attached to at least one of the heat-resistant films.