JPS634512A - Flat operation 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 the Invention The present invention relates to a flat switch used in electronic circuits of home appliances such as washing machines and microwave ovens.

BACKGROUND OF THE INVENTION Conventionally, this type of flat plate switch has been an open type switch. The structure will be explained with reference to FIG. 3. A first electrode 2 and a second electrode 3 are formed on a substrate 1 using a conductive material such as copper foil. A conductor 4 is disposed at a position facing the first electrode 2 and the second electrode 3.

The conductor 4 is integrated with a flexible plate 6 disposed on the substrate 1 with an adhesive layer 5 at a predetermined interval. The adhesive layer 5 is disposed intermittently around the outer periphery of the flexible plate 6, and vent holes 8 are formed between adjacent adhesive layers 6 to allow air to enter and exit the space 7. This switch normally has the first electrode (contact) 2 and the second electrode (contact) 3 in an open state, but when the flexible plate e near the conductor 4 is pressed, the conductor 4 and the first electrode 2
and the second electrode 3, and the first electrode 2
and the second electrode 3 are electrically connected, and the switch is in a closed state. When the force pushing the flexible plate 6 is removed, the conductor 4 separates from the first electrode 2 and the second electrode 3 due to the elasticity of the flexible plate 6, and the switch becomes open again.

The vent 8 is designed to prevent the space T from changing when pressure changes due to temperature changes in the space T or when pressure changes when the switch is pressed for switch operation.
This is provided to make the internal pressure and external pressure the same, so that switch operations can be performed without any trouble.

Problems to be Solved by the Invention In such a conventional configuration, when the switch is used in a place with a lot of moisture or in a place exposed to steam, water droplets enter from the vent hole 8 and the first electrode 2 and the second electrode 3 may become electrically conductive, or dust entering from the ventilation port 8 may obstruct electrical continuity, resulting in malfunction. Therefore, it can only be used indoors for equipment that is not exposed to water. Ta. In order to eliminate these drawbacks of the conventional example, it is conceivable to seal the vent 8 with an adhesive layer 5 with low air permeability, as shown in FIG. 4, to make the outer periphery of the space 7 airtight. . Conventionally, the flexible plate 6 is made of polyethylene terephthalate resin, which is a type of thermoplastic polyester resin, due to its electrical insulation properties, printing properties, and economic efficiency.
Lumu is using it. Further, the adhesive layer 5 is a double-sided adhesive tape made of a rayon nonwoven fabric 21 coated with an adhesive 22. However, according to these, when the temperature of the space 7 rises, the internal pressure rises and air escapes due to the slight air permeability of the nonwoven fabric 21 of the adhesive layer 5.
Next, when the temperature drops, the elasticity of the flexible plate 6 is not enough to suck in the outside air, so if the temperature repeats the rise and fall, the flexible plate 6 will gradually drop and the stroke when operating the switch will change. , conductor 4 to prevent malfunction
A sufficient gap between the image electrode 2.3 and the image electrode 2.3 cannot be secured. In addition, with such a configuration, moisture (gaseous water) that has flowed into the space 7 together with the air from the adhesive layer 5 or condensed in the moisture space 7 that has passed through the flexible plate 6 becomes liquid. Water gradually accumulates in the space 7, and it no longer functions as a switch.

The present invention solves these problems and aims to prevent malfunctions caused by moisture or dust in equipment that is exposed to moisture or steam, such as electric washing machines, or equipment that is used outdoors. be.

Means for Solving the Problem In order to solve this problem, the present invention uses a film with very low moisture permeability for the flexible plate, and uses a base material with very low air permeability and an adhesive as the adhesive layer. Alternatively, the flexible plate is formed of a synthetic resin adhesive, and the periphery of the flexible plate is continuously fixed to the substrate using this adhesive layer.

Function With this configuration, the space and the outside air are separated from each other by a film or adhesive layer with extremely low air permeability or moisture permeability, so not only lumps and liquid water, but also air and gaseous water can easily enter the space. This prevents air from escaping or liquid water from accumulating in the space, thereby preventing switch malfunctions.

EXAMPLE Hereinafter, an example of the present invention will be described with reference to FIG.

A first electrode 11 and a second electrode 12 are formed on a substrate 10 using a conductive material such as silver paste or copper foil. These picture electrodes 11.1
A conductor 13 is disposed at a position facing 2. This conductor 13 is integrated with a flexible plate 14.

The flexible plate 14 includes a synthetic resin film 19 and a moisture permeation suppressing layer 2.
The synthetic resin film 19 composed of
3 (for example, a conductive paint containing a large amount of silver), heat resistance properties during baking and solidification of the conductor 13, and economic efficiency, it is preferable to use a polyethylene terephthalate film as in the past, and a polyimide film is preferable. etc. can also be used. A moisture permeation suppressing layer 2o for reducing moisture permeation is bonded to this.

The table below shows an example of literature regarding the water vapor permeability of various plastic films.

It is effective to form the following with a blank polymer or vinyl chloride film. The flexible plate 14 with low moisture permeability of the present invention is formed by bonding these synthetic resin films onto the synthetic resin film 19 with an adhesive or by applying and solidifying a paint made of these resins.

Further, since metal has extremely low moisture permeability, the moisture permeation suppressing layer 20 may be formed of a vapor-deposited layer of metal such as aluminum. In this case, the metal vapor-deposited layer may be directly formed on the polyethylene terephthalate film 19, or the synthetic resin film with the metal vapor-deposited layer formed thereon may be bonded to the synthetic resin film 19.

Alternatively, the moisture permeation suppressing layer 20 may be formed of metal (for example, aluminum) foil and bonded to the synthetic resin film 19 to form the flexible plate 14 with low moisture permeability.

An adhesive layer 16 is continuously disposed around the outer periphery of these flexible plates 14 having low moisture permeability, and is bonded to the substrate 1o. One type of this adhesive layer 15 is a structure in which adhesive 17 is provided on both sides of a base material 16, and the base material 16 is not a non-woven fabric as in the conventional series, but a non-fibrous material such as a polyethylene terephthalate film. Use materials with extremely low air permeability, such as synthetic resin or metal foil. Further, the adhesive layer 16 may be made of only a synthetic resin such as a silicone resin or a vinyl chloride resin without using a base material.

In FIG. 1, the substrate 1o is made of a synthetic resin plate such as paper phenol, but as shown in FIG. The object of the present invention can be achieved in the same way even with a structure in which a base member 24 is formed and joined to a base material 24 made of metal or synthetic resin.

Under such a configuration, when the flexible plate 14 near the conductor 13 is pressed against the substrate 10 side and the conductor 13 is brought into contact with the picture electrodes 11 and 12 in order to close the switch, the volume of the space 18 is As it becomes smaller, the internal pressure increases. Moreover, the internal pressure of the sealed space 18 increases or decreases due to temperature changes.

Furthermore, the water vapor pressure difference (relative humidity difference) between the space 18 and the outside air
As a result, a pressure difference occurs between the internal pressure and the outside air.

Due to such a difference in air pressure and water vapor pressure, air and water vapor enter and exit between the space 18 and the outside air via the flexible plate 14 and the adhesive layer 15.

When a double-sided adhesive tape using a nonwoven rayon fabric 21 as in the conventional example is used for the adhesive layer 5, if the internal pressure in the space 7 remains high for a long time, the air in the space 7 gradually passes through the nonwoven fabric 21 made of rayon. When the temperature is returned to room temperature again, the internal pressure of the space 7 is lower than the initial state, so the flexible plate 6 falls. In the experiment, a double-sided adhesive tape using a rayon nonwoven fabric 21 was used as the adhesive layer 5, and a double-sided adhesive tape using a 25 μm thick PET film as the base material 16 was used as the adhesive layer 15, which is an example of the present invention. When the constructed flat plate operation switch was left in an 80'C atmosphere for 1,000 hours, it was confirmed that the amount of depression of the flexible plates 6 and 14 was more than 2.5 times that of the latter.

By using a film with low moisture permeability for the flexible plate 14, the infiltration of moisture into the space 18 can be significantly reduced. In the experiment, the flexible plate 14 was made of conventional PET with a thickness of 125 mm.
μm film (moisture permeability 6.9' according to JIS method;
7/wt7'24 h) and an example of the present invention, a PET film with a thickness of 10Oμm + a film made of vinylidene chloride with a thickness of 10μm (moisture permeability of 1.0y according to JIS method).
/Wl/24h) was immersed in hot water for 168 hours.
Although dew condensation was observed connecting the flexible plate 14' and the substrate 1g, no such condensation was observed on the latter.

Effects of the Invention As is clear from the description of the embodiments above, according to the present invention, the electrode portion of the switch can be protected from water droplets and dust, and even after being left in a high temperature atmosphere for a long time, the flexible plate will not fall. The switch is extremely reliable, preventing malfunctions, and is highly reliable even when used in high humidity or dusty environments.

[Brief explanation of the drawing]

FIG. 1 is a vertical cross-sectional view of a flat switch according to an embodiment of the present invention, FIG. 2 is a vertical cross-sectional view of a flat switch according to another embodiment of the present invention, and FIGS. FIG. 2 is a longitudinal cross-sectional view of a flat switch. 10... Substrate, 11.12... Middle electrode, 13
...River/conductor, 14...Flexible plate, 15...
... Adhesive layer, 1θ ... Base material, 17 ...
・Adhesive, 19...Synthetic resin film, 2o
...Moisture permeation control layer. Name of agent: Patent attorney Toshio Nakao and one other person lθ
-Basic scale 16-Base material u, tz ・-Electric a 17-1% 1 +J1
3.-Lecture body tq-Ichi Ni-gai Pilgrimage 1st move-Machi Kosai tile Film 15--↑wife 11 No effect 2θ--Ichito
) I71 Figure 2

Claims (5)

[Claims] (1) A plurality of electrodes are provided on the substrate, and a flexible plate with a conductor facing these electrodes is provided, and this flexible plate is secured with a distance from the substrate by an adhesive layer, and the outer periphery is continuous. A flat plate type operation in which the adhesive layer is formed of a material with low moisture permeability, and the flexible plate is formed by providing a moisture permeation suppressing layer on a synthetic resin film to reduce moisture permeation. switch. (2) The flexible plate has a synthetic resin film as a base material, and on top of this (a) a synthetic resin film formed of a material with lower moisture permeability than the synthetic resin film as the base material, (b) a synthetic resin film. 2. A flat plate type operation switch according to claim 1, wherein a film (c) metal foil on which a metal vapor deposited layer is formed is bonded as a moisture permeation suppressing layer. (3) The flexible plate has a synthetic resin film as a base material, and on top of this, (a) a synthetic resin coating film made of a material with less moisture permeability than a polyester film, and (b) a metal vapor deposition layer that is transparent. The flat plate operation switch according to claim 1, which is formed as a moisture suppression layer. (4) The flat plate operation switch according to claim 1, wherein the adhesive layer is formed of a synthetic resin film or metal foil base material coated with an adhesive. (5) The flat plate operation switch according to claim 1, wherein the adhesive layer is formed of a synthetic resin adhesive.