JPH0755779Y2 - Push-on switch - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial field of application] The present invention relates to a push-on switch.

[Prior Art] With the recent miniaturization of electronic products, a small and thin push-on switch that can be directly assembled on a substrate without a special case has been used. In these switches, a central contact point and an end contact point are formed on an insulating substrate, and a tact metal plate having a reversible dish-shaped portion that is curved so as to project in a direction away from the substrate is used as a dish-shaped plate. It is arranged on the substrate such that a part of the peripheral portion of the portion comes into contact with an end contact provided on the substrate. Then, in order to hold the tact metal plate at a predetermined position on the substrate, an insulating cover member is fixed to the substrate so as to cover the tact metal plate. In this switch, when the tact metal plate is pressed from the outside of the insulating cover member, the substantially central part of the tact metal plate contacts the central contact, and the central contact and the end contact are brought into conduction. Known examples of this type of switch include those disclosed in Japanese Utility Model Publication No. 1-100333.

In the conventional switch, although the insulating cover member is fixed to the substrate, the tact metal plate is held in place due to the structure of simply covering the tact metal plate, so that the tact metal plate does not move. Switch operation becomes uncertain.

Therefore, in order to prevent the movement of the tact metal plate, JP-A-63-63
-In the push-on type switch disclosed in the publication No. 43326,
A plate-shaped spacer having an opening for accommodating the tact metal plate is bonded onto the substrate, a thin elastic plate equivalent to an insulating cover member is mounted on the spacer, and the tact metal plate of this thin plate is accommodated. An air vent slit is formed in the portion covering the opening.

[Problems to be Solved by the Invention] In the push-on type switch disclosed in Japanese Patent Laid-Open No. 63-43326, the tact metal plate is housed in the opening formed in the spacer bonded to the substrate. There is no movement of the metal plate. Therefore, the air vent slit is formed only in the portion that covers the opening of the thin plate. However, if the spacer is used, not only the number of parts is increased, but also the spacer hinders the deformation of the thin plate when the tact metal plate is deformed, which deteriorates the operability.

An object of the present invention is to provide a push-on type switch that does not use a spacer and prevents the movement of the tact metal plate to ensure a switch operation.

Another object of the present invention is to provide a push-on switch that can follow the deformation of the tact metal plate when the insulating cover member, the tact metal plate, and the adhesive are joined together with an adhesive.

Still another object of the present invention is to provide a push-on type switch that can smoothly perform air removal even when an insulating cover member and a tact metal plate are joined with an adhesive.

[Means for Solving the Problems] The present invention is directed to an insulating substrate having a central contact and an end contact formed thereon, and a part of a peripheral portion of which is disposed on the substrate so as to contact the end contact. A tact metal plate having a dish-like portion that can be inverted so as to project in a direction away from the substrate, and a tact metal plate that covers the tact metal plate to hold the tact metal plate at a predetermined position on the insulating substrate. An insulating cover member fixed to the substrate, and when the dish-shaped portion of the tact metal plate is pressed from the outside of the insulating cover member, the substantially central portion of the dish-shaped portion abuts the central contact point and the central contact point The target is a push-on switch in which the end contact is electrically connected to the switch. And in this invention, in order to solve the said subject, a tact metal plate and an insulating cover member are joined via an adhesive agent.

The tact metal plate may be composed of only the dish-shaped portion, or may have a flange portion outside the dish-shaped portion.

In particular, in the present invention, even when the insulating cover member and the tact metal plate are joined with an adhesive, the tact metal plate of the insulating cover member is formed in order to facilitate the deformation of the insulating cover member and enable smooth air venting. To the part corresponding to
At least two slits are formed so as to be arranged side by side with a predetermined gap, and both ends of the slits are extended to positions beyond the peripheral edge of the tact metal plate.

[Operation of the Invention] As in the present invention, when the tact metal plate and the insulating cover member are joined via an adhesive, the insulating cover member can be formed without using a spacer having an opening for accommodating the tact substrate plate. Since the tact metal plate can be reliably held at a predetermined position while following the tact metal plate, the switch operation can be reliably performed without lowering the operability.

By joining the insulating cover member and the tact metal plate with an adhesive, the insulating cover member can be deformed following the tact metal plate. However, if the switching operation is frequently performed for a long period of time, the adhesiveness and adhesiveness of the adhesive may be deteriorated, which may cause a situation in which the insulating cover member cannot be deformed by following the tact metal plate. is expected. Therefore, as in the present invention, at least two slits are formed in a portion of the insulating cover member corresponding to the tact metal plate so as to be arranged side by side with a predetermined gap, and both ends of the slit are formed at the peripheral edge of the tact metal plate. When it is extended to a position exceeding the above, the portion of the insulating cover member located between the two slits is in a state where both ends are fixed. Compared with the case where the entire periphery is fixed without forming the slit, the degree of freedom of the portion sandwiched between the slits and where the both ends are fixed is high.
Therefore, even when the switch operation is frequently performed over a long period of time, a part of the insulating cover member can be surely made to follow the deformation of the tact metal plate, and the tact metal plate can be held at a predetermined position. Further, since the slit also functions as an air vent, the operability of the switch is improved. According to the present invention, most of the air escapes from the slit portion extending beyond the outer peripheral edge portion of the tact metal plate, which may impair the adhesiveness between the tact metal plate and the insulating cover member. Almost never.

Embodiments Embodiments of the present invention will be described in detail below with reference to the drawings.

FIG. 1 (A) is a schematic side view when the push-on type switch of one embodiment of the present invention is used in a volume control circuit of a portable stereo, and FIG. 1 (B) is a schematic rear view thereof.
FIG. 2 is a sectional view taken along the line II-II of FIG. 1 (B). Further, FIG. 3 is a plan view of a single switch shown by using imaginary lines for explaining the structure of the switch. In these figures, 1 is a circuit board having an insulating property. Note that a flexible substrate having flexibility may be used. A predetermined circuit pattern is formed on the substrate 1 by using copper foil, silver paint, or conductive paint such as carbon. Although the circuit pattern is not shown in FIGS. 1A and 1B, the contact pattern of the switch is also included in the circuit pattern as shown in FIGS. 2 and 3. 2 and 3, 2 is a central contact point, 3 is an end contact point, and 4a and 4b are jumper wires. An overcoat 5 is formed on the jumper wire 4b connected to the center contact 2 by using an appropriate insulating material such as epoxy resin. In this embodiment, the thickness of the overcoat 5 is set to about 50 μm, and the thickness of the average overcoat used in a known switch (about 10 μm) is about 5 μm.
Doubled. When a part of the tact metal plate described later is placed on the thick overcoat 5, the click feeling becomes large. In FIGS. 2 and 3, each part is exaggerated for ease of understanding.

Reference numeral 6 is a tact metal plate that is composed only of a dish-shaped portion that is curved so as to project in a direction away from the substrate 1 and that can be inverted. The tact metal plate 6 is mounted on the substrate 1 such that a part of the peripheral edge portion 6a thereof is in constant contact with the end contact 3. Reference numeral 7 is an insulating cover member having insulating properties and flexibility, and can be formed using, for example, a polyester sheet or the like. In this embodiment, a flat polyester sheet cut according to the circuit pattern formed on the substrate 1 is used as the insulating cover member 7. In order to facilitate positioning during assembly, it is preferable to use a transparent or translucent insulating cover member 7. In this embodiment, two slits 8, 8 are formed in a portion of the insulating cover member 7 corresponding to the tact metal plate 6 so as to be arranged at a predetermined interval, and both ends of the slit 8 are tact. It extends to a position beyond the peripheral edge 6a of the metal plate 6. 2 and 3, the gap size of the slits 8 is exaggeratedly drawn, but these slits 8 are formed by cutting the insulating cover member 7 with a blade, and in actuality, it is slightly It is a thing.

An adhesive 9 is applied to the back surface of the insulating cover member 7, and the insulating cover member 7 and the tact metal plate 6 are joined to each other via the adhesive 9. The adhesive 9 may be any adhesive as long as it can follow the deformation of the insulating cover member 7 and the tact metal plate 6 to some extent without hardening and having adhesiveness and holding power. In this embodiment, FSK Co.
An acrylic adhesive sold under the trade name of Shin was used. This adhesive has excellent transparency, and even if it is peeled off, it is rejoined to the article to be joined if a predetermined pressing force is applied again.

The two slits 8 and 8 are provided as deformation promoting groove portions that allow the deformation of the insulating cover member 7 to follow the deformation of the tact metal plate 6 and hold the tact metal plate at a predetermined position. Two
Part 7a of the insulating cover member 7 sandwiched between the slits 8 of the book
Has a structure in which both ends are fixed to the substrate 1 with the adhesive 9, and the degree of freedom of deformation is high. Therefore, when the tact metal plate 6 is pressed and deformed, the adhesive 9 does not have much adhesive force or holding force, or due to secular change.
If the holding force of the tact metal plate 6 is peeled off even if the part 7b of the insulating cover member 7 located outside the slit 8 and the tact metal plate 6 are separated, It rarely comes off. Particularly, as in this embodiment, when both ends of the slit 8 are sufficiently extended to the position beyond the peripheral edge portion 6a of the tact metal plate 6, the deformation of the portion 7a becomes easy. Further, the air in the space formed between the tact metal plate 6 and the substrate 1 can be discharged to the outside through a part of the slit 8, and the air can be satisfactorily discharged.

The number, position and shape of the slits 8 are not limited to those in the above embodiment, and three or more slits may be formed if necessary. The interval between the slits 8, 8 can be arbitrarily changed as long as the deformation of the corresponding portion 7a of the insulating cover member 7 can follow the deformation of the tact metal plate 6.

In FIGS. 1A and 1B, 10 is a push-on type switch having the structure of the above embodiment, 11 is a variable resistor,
Reference numeral 12 is an electronic component such as a transistor. Processes for assembling the circuit device of FIG. 1 will be described.

First, the circuit board 1 having a predetermined contact pattern on the back surface is manufactured. Positioning recesses or holes 1a are formed in at least two locations on the circuit board. The necessary overcoat 5 is also formed on the substrate 1 in advance. Then, the substrate 1 is placed on a jig (not shown) having two protrusions for positioning, with the variable resistor 11 facing downward while inserting the hole 1a of the substrate 1 into the protrusion. Next, in the portion where the slit 8 of the insulating cover member 7 having the back surface coated with the adhesive 9 is formed,
Attach the tact metal plate 6. And the insulating cover member 7
The surface coated with the adhesive 9 is attached to the back surface of the substrate 1. The insulating cover member 7 is formed with a positioning hole or a concave portion 7c provided corresponding to the hole 1a of the substrate 1, and the concave portion 7c is fitted to the protrusion of the jig to form the insulating cover member 7 on the substrate. When it is lowered to the 1 side, the tact metal plate 6 can be positioned on a predetermined contact pattern of the substrate 1. After the insulating cover member 7 is placed on the substrate 1, a predetermined pressure is applied between them to bond the insulating cover member 7 to the substrate 1, and the substrate 1 is separated from the jig to complete the assembly.

FIG. 4 shows an embodiment in which the present invention is applied to a switch having a tact metal plate with a flange portion. In FIG. 4, 15 is an overcoat, 16 is a tact metal plate with a flange portion, and 28 is a slit. When the tact metal plate 16 with the flange portion is used as in this embodiment, the tact metal plate can be easily positioned. However, since it is difficult to bleed air, in this embodiment, in order to facilitate air bleeding, notches 16C ... Are formed in the outer peripheral edge of the flange portion 16B corresponding to the slit 28, and the dish-shaped portion 16A and the flange are formed. Windows 16D ... Are formed so as to straddle the portion 16B. The cutout portion 16C and the window portion 16D make air venting smoother. In this embodiment, the slits 28, 28 are bent outward and bent so that the central portion faces (wide-angle V-shape).
I am trying. As a result, the area of the portion 7a of the insulating cover member 7 sandwiched between the two slits 28, 28 is increased. Further, in this embodiment, the overcoat 15 is formed to be large corresponding to the side of the flange portion 16a of the tact metal plate 16, and its thickness is the same as in the embodiment of FIGS. 2 and 3.
The thickness is about 5 times the normal thickness. This way,
Using a tact metal plate with a flange that tends to reduce the click feeling compared to a tact metal plate consisting of only a dish-shaped part,
A relatively large click feeling can be obtained.

[Advantage of the Invention] According to the invention of claim 1, since the tact metal plate and the insulating cover member are joined via an adhesive having an adhesive property, the insulating cover member is deformed by following the tact metal plate. Therefore, the tact metal plate can be securely held at a predetermined position, and the switch operation can be reliably performed without lowering the operability.

Particularly, according to the present invention, at least two slits are formed in a portion of the insulating cover member corresponding to the tact metal plate so as to be arranged at a predetermined interval, and both ends of the slit are formed on the periphery of the tact metal plate. Since it extends to the position beyond the part, even if the switch operation is frequently performed for a long period of time, part of the insulating cover member is made to follow the deformation of the tact metal plate securely and the tact metal plate is held at the predetermined position. can do.

[Brief description of drawings]

1A is a side view of a circuit device having a push-on switch according to an embodiment of the present invention, FIG. 1B is a rear view of the device of FIG. 1A, and FIG. II-II in Fig. 1 (B)
FIG. 3 is a perspective view for explaining the configuration of a push-on type switch according to an embodiment of the present invention, and FIG. 4 is an embodiment of the present invention applied to a switch having a tact metal plate with a flange portion. It is a perspective view for explaining an example of a case. 1 ... Insulating substrate, 2 ... Central contact point, 3 ... End contact point, 5,15 ... Overcoat, 6,16 ... Tact metal plate,
6a …… Tact metal plate peripheral edge, 7 …… Insulation cover member,
8,28 ... Slit, 9 ... Adhesive, 10 ... Push-on type switch, 18 ... Groove.

Claims (2)

[Scope of utility model registration request] 1. An insulative substrate having a central contact and an end contact, and an insulating substrate disposed on the substrate so that a part of a peripheral edge thereof abuts the end contact and facing away from the substrate. A tact metal plate having a dish-like portion that is capable of reversing operation and curved so as to project, and a tact metal plate that covers the tact metal plate to hold the tact metal plate at a predetermined position on the insulating substrate. An insulating cover member is fixed, and when the dish-shaped portion is pressed from the outside of the insulation cover member, a substantially central portion of the dish-shaped portion abuts the central contact point and the central contact point and the central contact point. In a push-on switch in which an end contact is in conduction, the tact metal plate and the insulating cover member are joined via an adhesive having an adhesive property, and the tact metal plate of the insulating cover member is Dish At least two slits are formed in a portion corresponding to the above so as to be arranged at a predetermined interval, and both ends of the slits extend to positions beyond the outer peripheral edge of the tact metal plate. Push-on type switch. 2. The push-on switch according to claim 1, wherein the tact metal plate has a flange portion on a peripheral portion of the dish-shaped portion.