JPH09245563A - Membrane switch - Google Patents

Abstract

PROBLEM TO BE SOLVED: To make a load suitably adjustable which is loaded on, by forming a lower electrode in a position oppositely facing an upper electrode, and laminating a spacer, formed with a prescribed space part between the upper/lower electrodes, and a conductive elastic unit interposed. SOLUTION: An upper electrode 12 of copper foil and carbon film is formed in one surface of a reverse side of a base film 11, a lower electrode 14 is formed in one surface of a base film 13, a dot-shaped spacer 15 is provided with a suitable space in a surface of the electrode 14. Between the electrodes 12, 14, a film-shaped conductive elastic unit 20 is layered in a side of the electrode 12 of the spacer 15, to be brought into contact with the electrode 12. In a membrane switch 10, a lead pattern 22 respectively connected to the electrodes 12, 14 is extended via a flexible lead wire forming part, to be connected to the other circuit board. In the switch 10, the elastic unit 20 is interposed between the electrodes 12, 14, so as to make a load easily adjustable which is loaded on, by suitably adjusting elasticity of the elastic unit 20.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a membrane switch used for an operation panel or a touch panel of electronic equipment.

[0002]

2. Description of the Related Art Conventionally, a membrane switch can be formed on the surface of any place without taking up a space, and has been used in many electronic devices. As shown in FIGS. 3 and 4, the conventional membrane switch has a base film 1 made of polyethylene terephthalate or polyimide, and an upper electrode 2 made of copper foil or carbon formed on one surface of the base film 1. Similarly, a lower electrode 4 is formed on one surface, dot-like spacers 5 are provided on the surface of the lower electrode 4 at appropriate intervals, and the upper electrode 2 and the lower electrode 4 are faced to each other with a constant space therebetween and bonded to each other. It is a thing. Then, by pressing the base film 1 on the front surface side, the upper electrode 2 and the lower electrode 4 come into contact with each other to close the contact.

[0003]

The above-mentioned conventional membrane switch has the following problems in adjusting the pressing load to be turned on.
It is necessary to change the hardness of the base films 1 and 3 on the front and back and the distance between the spacers 5. However, it was impossible to finely adjust the hardness of the base films 1 and 3 and the distance between the spacers 5. In particular, the elasticity of the base films 1 and 3 is weak, and there is a problem in that it is not possible to form a contact that turns on under a high load.

The present invention has been made in view of the above-mentioned problems of the prior art, and an object of the present invention is to provide a membrane switch capable of arbitrarily setting a load for closing a contact with high precision.

[0005]

According to the present invention, an upper electrode is formed on one surface of an insulating base film, and a lower electrode is formed at a position facing the upper electrode. A spacer having a dot shape or a through hole forming a predetermined space is interposed between the film and a conductive elastic body having a film shape.

Further, the conductive elastic body may also serve as the upper electrode, and the base film on the upper electrode side of the base film is formed of an elastic body, and the base film on the lower electrode side is made hard. You may form with the film of.

In the membrane switch of the present invention, the load at which the upper electrode and the lower electrode are turned on can be arbitrarily set by the elasticity of the conductive elastic body and the size, height, or density of the dod spacer. .

[0008]

Embodiments of the present invention will be described below with reference to the drawings. 1 and 2 show a membrane switch 10 of this embodiment,
This membrane switch 10 is provided with a sheet-like base film 11 made of an insulating synthetic resin such as polyethylene terephthalate or polyimide. There is. Further, a lower electrode 14 is formed on one surface of another similar base film 13 similarly to the upper electrode 12, and dot-shaped spacers 15 are provided on the surface of the lower electrode 14 at appropriate intervals. This dot spacer 15
Is the lower electrode 1 with a certain interval such as UV curable resin.
4 are formed.

A film-shaped conductive elastic body 20 is laminated between the upper electrode 12 and the lower electrode 14 on the side of the upper electrode 12 of the spacer 15, and is in contact with the upper electrode 12. The conductive elastic body 20 is a film in which conductive particles such as silver are mixed in silicon rubber or the like to give conductivity.

In this membrane switch 10, lead patterns 22 respectively connected to the upper electrode 12 and the lower electrode 14 extend through a flexible lead wire forming portion,
The end portion is exposed to the outside and is connected to another circuit board or a flexible board.

The membrane switch 10 is attached to the surface of various electronic devices and is used as a switch for performing a predetermined operation. Further, a portion where a normal contact cannot be formed, for example, a steering wheel portion of an automobile. It is also used as a contact.

Since the conductive elastic body 20 is interposed between the upper electrode 12 and the lower electrode 14 in the membrane switch of this embodiment, it can be easily turned on by appropriately adjusting the elasticity of the conductive elastic body 20. It is possible to adjust the load to
Further, depending on the size, height, density, etc. of the dod spacer, the upper electrode 12 and the lower electrode 14 are turned on more finely.
The load to be set can be set.

Thus, it is possible to form an appropriate switch from one that is turned on with a light touch to one that is turned on with a strong force depending on the use of the contact.

Further, the conductive elastic body may also serve as the upper electrode, in which case one lead pattern may be formed to extend from the upper electrode of the elastic body. Alternatively, the base film on the upper electrode side of the base film may be formed of an elastic body, and the base film on the lower electrode side may be relatively thick and formed of a hard film.

The present invention is not limited to the above-mentioned embodiment, but the base film, the material of the electrode and the like can be changed appropriately. Further, the spacers may be not only dot-shaped ones but also spacers in which through holes are formed at a predetermined pitch and the upper electrode and the lower electrode can be brought into contact with each other by pressing through the through holes.

[0016]

EFFECTS OF THE INVENTION The membrane switch of the present invention has a conductive elastic body interposed on the upper electrode side, and the elasticity of the conductive elastic body is appropriately adjusted to adjust the necessary pressing force by the dod spacer. O due to the conductive elastic body
This makes it possible to appropriately adjust the load applied to N, thereby enabling finer adjustment of the contacts.

[Brief description of drawings]

FIG. 1 is a perspective view of a membrane switch according to an embodiment of the present invention.

FIG. 2 is a partial vertical cross-sectional view of the membrane switch of this embodiment.

FIG. 3 is a perspective view of a prior art membrane switch.

FIG. 4 is a partial vertical sectional view of a conventional membrane switch.

[Explanation of symbols]

 1,3,11,13 Base film 2,12 Upper electrode 4,14 Lower electrode 5,15 Spacer 10 Membrane switch 20 Conductive elastic body

Claims (3)

[Claims] 1. An upper electrode is formed on one surface of an insulating base film, a lower electrode is formed at a position facing the upper electrode, and a predetermined space is provided between the upper electrode and the lower electrode. A membrane switch in which a spacer to be formed and a film-shaped conductive elastic body are laminated and interposed. 2. The membrane switch according to claim 1, wherein the conductive elastic body also serves as an upper electrode. 3. The membrane switch according to claim 1, wherein the base film on the upper electrode side of the base film is formed of an elastic body, and the base film on the lower electrode side is formed of a hard film.