JPH09223432A - Matrix type switch - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a matrix type switch which can be made thin, manufactured easily, and has no defect due to assembly errors. SOLUTION: Three first circuit patterns 11 are formed in parallel on a flexible board 10, pressure sensitive resistance films 21 to lower their resistance values in the thickness direction are formed by pushing down prescribed points of the first circuit patterns 11, and moreover four second circuit patterns 31 are so formed in parallel as to cross these three first circuit patterns 11 and pass the pressure sensitive resistance films 21 at the crossing points. The crossing points of the first and the second circuit patterns 11, 31 are made to be switch contacts 20 which turn on the crossing points of the first and the second circuit patterns 11, 31 by pushing the pressure sensitive resistance films 21 at the crossing points in the thickness direction.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a matrix type switch in which a large number of switch contacts are arranged in a matrix on a plane.

[0002]

2. Description of the Related Art Conventionally, as a matrix type switch of this type, there has been one having a structure as shown in FIGS.

That is, in the matrix type switch shown in FIG. 10, a spacer 88 is placed on a flexible substrate 81 on which a plurality of (three in the figure) circuit patterns 82 are formed in parallel, and a plurality of spacers 88 are placed on the spacer 88. Then, a flexible substrate 85 having three circuit patterns 86 formed in parallel is mounted.

Contact points 83 and 87 are provided at the intersections of the circuit pattern 82 and the circuit pattern 86, respectively. A circular through hole 89 is provided at the intersection of the spacer 88.

When any one of the contact portions 87 of the flexible substrate 85 is pressed, the contact portion 87 is pushed through the through hole 89.
To contact the contact portion 83 directly thereunder, and the contact between the circuit patterns 82 and 86 is turned on.

The matrix type switch shown in FIG.
Two flexible substrates 9 similar to those shown in FIG.
A sheet of anisotropic pressure-sensitive rubber sheet 9 between 1 and 95 is pressed in the thickness direction instead of the spacer to turn on only the pressed portion in the thickness direction (to reduce the resistance value).
8 is interposed.

When any one of the contact portions 97 of the flexible substrate 95 is pressed, the anisotropic pressure-sensitive rubber sheet 98 directly below the contact portions 97 is pressed, so that the contact portions 97 and the contact portions 93 therebelow. Are electrically connected, and the electrically connected circuit patterns 92 and 96 are turned on.

The matrix type switch shown in FIG.
Nine switch patterns 103 provided with two electrode portions 105 and 106 facing each other are formed in a matrix on one flexible substrate 101, and each switch pattern 10 is formed.
3 from the electrode portion 105 on one side of the three circuit patterns 10
7 is pulled out, three circuit patterns 109 are pulled out from the electrode portion 106 on the other side, and the film plate 11 is placed on the flexible substrate 101 via the spacer 111.
3 is attached.

Two of the circuit patterns 107 are arranged on the back surface of the flexible substrate 101 via through holes 110 so as not to come into contact with the circuit pattern 109.

When any one of the switch patterns 103 on the film plate 113 is pressed, the film plate 11 is pressed.
The conductive pattern 115 provided on the lower surface of 3 electrically connects between the two electrode portions 105 and 106 of the switch pattern 103, whereby the electrically connected circuit patterns 107 and 109 are turned on.

[0011]

However, in any of the above-mentioned conventional examples, since the structure in which a plurality of members are superposed on each other is used, not only is the thickness increased, and further reduction in thickness cannot be achieved, but the assembly process is complicated. There was a problem that was.

Further, each contact portion 83, 87 (93, 97, 1)
The flexible boards 81, 85 (91, 95, 101, 113) must be accurately positioned and assembled so that (03, 115) exactly face each other, and there is a possibility that a defect may occur due to an assembly error.

In the case of the conventional example shown in FIG. 11, there is also a problem that the anisotropic pressure-sensitive rubber sheet 98 used is expensive.

On the other hand, in the case of the conventional example shown in FIG. 12, since the through hole 110 has to be formed, there is a problem that the manufacturing process is complicated.

The present invention has been made in view of the above points, and an object thereof is to provide a matrix type switch which can be made thin, easy to manufacture, and free from defects due to assembly errors.

[0016]

In order to solve the above-mentioned problems, the present invention is to form a plurality of first circuit patterns in parallel on a base material and to place them at predetermined positions on the first circuit pattern. A pressure-sensitive resistive film is formed that reduces the resistance value in the thickness direction by pressing in the thickness direction, and further crosses the plurality of first circuit patterns and passes over the pressure-sensitive resistive film at the intersection. As described above, a plurality of second circuit patterns are formed in parallel, and the intersections of the first and second circuit patterns are pressed in the thickness direction of the pressure-sensitive resistive film, whereby the first and second circuits at the intersections are formed. A matrix type switch with switch contacts for turning on between patterns was constructed.

[0017]

Embodiments of the present invention will be described below in detail with reference to the drawings. Here, FIG. 1A is a perspective view showing a state where the matrix type switch according to the embodiment of the present invention is viewed from the upper side, and FIG. 1B is a perspective view showing a state viewed from the lower side. .

As shown in the figure, this matrix type switch is composed of only one flexible substrate 10. Specifically, the three first circuit patterns 11 formed in parallel are formed on the lower surface of one flexible substrate 10.
And four second circuit patterns 31 formed in parallel so as to be orthogonal to the first circuit pattern 11 and a switch contact 20 (12) formed at the intersection of both patterns.
Places) and are provided.

FIG. 2 is an enlarged detailed view of the switch contact 20, and FIG. 2 (a) is a plan view.
9B is a sectional view taken along the line AA of FIG. 9A, and FIG.

As shown in the figure, the switch contact 20 has a first circuit pattern 11 formed on the lower surface of the flexible substrate 10, and the switch contact 20 of the first circuit pattern 11 is formed.
The circular pressure-sensitive resistance film 21 is formed so as to cover the circular contact portion 13 provided in the portion to be formed, and the second circuit pattern 31 is formed so as to pass over the pressure-sensitive resistance film 21. Is configured.

A circular contact portion 33 is also provided at a position facing the contact portion 13 of the second circuit pattern 31.

The portion of the flexible substrate 10 that serves as the switch contact 20 is curved so as to be convex upward, and thereby the dome-shaped pressing portion 15 is formed.

The detailed structure of this matrix type switch will be described below together with its manufacturing method. 3 to 6 are views showing a method of manufacturing a matrix type switch.

In order to manufacture this matrix type switch, first, as shown in FIG. 3, a flexible substrate 10 having flexibility is prepared, and three first circuit patterns 11 are arranged in parallel on one surface thereof. Form.

The flexible substrate 10 is made of a flexible synthetic resin film, and in this embodiment, a PET (polyethylene terephthalate) film having a thickness of 125 μm is used.

On the other hand, the first circuit pattern 11 is formed by printing or the like, but in this embodiment, it is formed by screen-printing a silver paste, a land portion 12 is provided at one end thereof, and a switch contact is formed. A circular contact portion 13 is provided in each of the portions 20. In this embodiment, the thickness of the first circuit pattern 11 is about 10 μm.

Next, as shown in FIG. 4, each of the contact portions 13
A circular pressure-sensitive resistance film 21 that covers the contact portion 13 is formed thereon.

The pressure-sensitive resistance film 21 is formed by printing a pressure-sensitive material having a function of reducing the resistance value in the thickness direction by pressing in the thickness direction. In this embodiment, the pressure sensitive resistance film 21 has a thickness of 40 to 100 μm.

In this embodiment, as the pressure sensitive resistance film 21, an anisotropic pressure sensitive resistance film whose resistance value changes only in the pressing direction and remains in an insulating state in the other directions is used. As the material of the pressure-sensitive resistance film 21, an elastic material mixed with conductive powder is used. Specifically, in this embodiment, silicon rubber is used as the elastic material, carbon powder is used as the conductive powder, and 1.0 part by weight of carbon powder is mixed with 15.0 to 0.2 parts by weight of silicon rubber. Is dissolved in a solvent such as a terpene-based high boiling point solvent. As the carbon powder, granulated carbon black having an average particle size of 1 to 20 μm is used.

The elastic material is not limited to silicone rubber, but other various rubber materials (eg, butadiene rubber, acrylonitrile / butadiene / styrene rubber, etc.) or thermoplastic elastomers (eg, styrene-based thermoplastic elastomer, olefin-based material). A thermoplastic elastomer or the like), a vinyl chloride / vinyl acetate resin material, or a material having various elasticity such as polyethylene can be used.

As the material of the conductive powder, in addition to granulated carbon black, spherical graphite, beaded graphite, scaly graphite,
Flake graphite, earth graphite and the like can be used, and a mixture thereof may be used. Other conductive metal powders may also be used.

Next, as shown in FIG. 5, four second circuit patterns 31 are arranged in parallel on the flexible substrate 10 and are orthogonal to the first circuit pattern 11, and the pressure sensitive resistance film 21. Form to pass over.

The second circuit pattern 21 is formed by printing or the like. In this embodiment, it is formed by screen-printing a silver paste, a land portion 32 is provided at one end thereof, and a switch contact is formed. A circular contact portion 33 is provided in each of the portions 20. In this embodiment, the thickness of the second circuit pattern 21 is about 10 μm.

Then, as shown in FIG. 6, the portion of the flexible substrate 10 provided with the pressure sensitive resistance film 21 is heated.
The dome-shaped pressing portion 15 is formed by curving so as to be convex toward the surface side where the pressure sensitive resistance film 21 is not provided (that is, the upper surface side shown in FIG. 1) by molding by pressing. In this embodiment, the dome-shaped pressing portion 15 has a diameter of 5 mm and a height of 0.5 mm.

In order to operate the matrix type switch, as shown in FIG. 7, the matrix type switch is placed on the support member 40, and a predetermined dome-shaped pressing portion 15 is pressed, whereby the dome-shaped switch is pressed. The pressing portion 15 is inversely deformed while generating a click sensation, the pressure-sensitive resistance film 21 is pressed in the thickness direction, and the resistance value in the thickness direction becomes small, whereby the predetermined contact points 13 and 33 are electrically connected, The conduction between the first and second circuit patterns 11 and 31 is turned on. As a result, the signal of the switch corresponding to the matrix can be taken out. When the pressing is released, the dome-shaped pressing portion 15 returns to its original position and is turned off.

By the way, the supporting member 40 may be made of a hard insulating plate such as a mold resin, an insulating film formed on a metal plate, or a mold case itself, or a film shape. It may be a substrate.

If the pressing stroke of the dome-shaped pressing portion 15 is insufficient, a spacer 88 as shown in FIG. 10 may be interposed between the matrix type switch and the supporting member 40 to increase the pressing stroke, or The pressing stroke may be lengthened by providing a recess on the support member 40.

In the case of this embodiment, since the matrix type switch has flexibility, even if the supporting member 40 to be attached has a curved surface, it can be attached so as to be curved and easily adhered thereto.

FIG. 8 is a schematic side sectional view showing a switch contact 20-2 having another structure which can be used in the present invention. This switch contact 20-2 is different from the switch contact 20 shown in FIG.
The only difference is that the dome-shaped pressing portion 15 is not formed at 0-2.

In the case of this matrix type switch, since there is no dome-shaped pressing portion 15, when actually using it,
As shown in the figure, a recess 41-2 is provided in a support member 40-2 arranged below the matrix type switch,
A spacer 8 having a through hole 89 as shown in FIG.
8 may be arranged below the matrix type switch.

In each of the above embodiments, an example in which the matrix type switch is formed on the flexible substrate has been shown, but the matrix type switch according to the present invention is not fixed on the flexible substrate but on a rigid substrate or other various fixings. You may form on a member.

FIG. 9 is a perspective view showing an embodiment in which a matrix type switch is formed on a hard substrate. This embodiment is different from the embodiment shown in FIG. 1 in that
It is only that the rigid substrate 10-3 is used instead of the flexible substrate 10 and the formed switch contact 20-3 is directed upward. Naturally, the dome-shaped pressing portion 15 shown in FIG. 1 is not formed.

It is the same as in each of the above-described embodiments that when any one of the switch contacts 20-3 of the matrix type switch configured as described above is pressed, the switch contact 20-3 is turned on. At this time, a key top for pressing the switch contact 20-3 may be arranged on the switch contact 20-3, or a flexible resin film or a rubber plate may be placed.

If an insulating protective film is formed on the switch contact of each of the above embodiments by screen printing, the switch contact is protected from mechanical wear.

[0045]

As described in detail above, according to the present invention, since the matrix type switch can be formed on one substrate, its thickness can be reduced, and a pattern forming technique for printing or the like. Since it can be manufactured only by itself, it has an excellent effect that the manufacturing is easy and no assembly error occurs.

[Brief description of drawings]

FIG. 1A is a perspective view showing a state where a matrix type switch according to an embodiment of the present invention is viewed from above, and FIG. 1B is a perspective view showing a state where viewed from below. Is.

2A and 2B are enlarged and detailed views of a portion of a switch contact 20, where FIG. 2A is a plan view, FIG. 2B is a sectional view taken along line AA of FIG. 2A, and FIG. c) is a rear view.

FIG. 3 is a diagram showing a method of manufacturing a matrix type switch.

FIG. 4 is a diagram showing a method of manufacturing a matrix type switch.

FIG. 5 is a diagram showing a method of manufacturing a matrix type switch.

FIG. 6 is a diagram showing a method of manufacturing a matrix type switch.

FIG. 7 is a diagram showing one usage example of a matrix type switch.

FIG. 8 is a schematic side sectional view of an essential part showing a switch contact 20-2 having another structure that can be used in the present invention.

FIG. 9 is a perspective view showing an embodiment in which a matrix type switch is formed on a hard substrate.

FIG. 10 is an exploded perspective view showing a conventional matrix type switch.

FIG. 11 is an exploded perspective view showing a conventional matrix type switch.

FIG. 12 is an exploded perspective view showing a conventional matrix type switch.

[Explanation of symbols]

 10 flexible substrate (base material) 11 first circuit pattern 15 dome-shaped pressing portion 20 switch contact 21 pressure-sensitive resistive film 31 second circuit pattern

Claims (1)

[Claims] 1. A resistance value in the thickness direction is reduced by forming a plurality of first circuit patterns in parallel on a base material and pressing the first circuit pattern in a predetermined position on the first circuit pattern in the thickness direction. Forming a pressure sensitive resistance film, and further forming a plurality of second circuit patterns in parallel so as to intersect with the plurality of first circuit patterns and pass over the pressure sensitive resistance film at the intersections. A matrix which is a switch contact which is turned on between the first and second circuit patterns at the intersection by pressing the intersection of the first and second circuit patterns in the thickness direction of the pressure sensitive resistive film. Type switch.