JP3010151B2 - Push-on switch - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a push-on switch.

[0002]

2. Description of the Related Art Recently, with the miniaturization of electronic products, small and thin push-on switches that can be directly assembled on a substrate without special cases have been used. In these switches, a center metal contact and an end contact are formed on an insulating substrate, and a tact metal plate having a reversible dish-shaped portion curved so as to protrude in a direction away from the substrate is formed by a dish-shaped metal plate. It is arranged on the substrate so that a part of the peripheral portion of the portion comes into contact with an end contact provided on the substrate.
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 portion of the tact metal plate comes into contact with the center contact, and the center contact and the end contact are brought into a conductive state. A well-known example of this type of switch is disclosed in Japanese Utility Model Laid-Open Publication No. 1-100333. In this switch, although the insulating cover member is fixed to the substrate, the tact metal plate is held at a predetermined position by a structure merely covering the tact metal plate, so that the tact metal plate moves. However, there is a problem that the switch operation becomes uncertain.

Accordingly, a technique has been proposed for joining a tact metal plate and an insulating cover member using an adhesive.

[0004]

Even when the tact metal plate and the insulating cover member are joined by using an adhesive, the switch operation is repeated, or the overcoat formed on the jumper wire connected to the center contact point is formed. When a part of the peripheral edge of the tact metal plate is brought into contact with the top of the tact metal plate to increase the click feeling by increasing the distance between the center contact and the tact metal plate, the reversal operation of the tact metal plate becomes large. As a result, it becomes difficult for the adhesive provided between the tact metal plate and the insulating cover member to exhibit a bonding function (that is, it becomes easy to peel off), and there is a problem that the tact metal plate easily moves.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a push-on type switch in which a tact metal plate is prevented from moving and a switch operation can be performed reliably.

Another object of the present invention is to provide a push-on switch which can reliably follow the deformation of the tact metal plate when the insulating cover member and the tact metal plate are bonded with an adhesive. To provide.

[0007]

According to the present invention, there is provided an insulating substrate having a center contact and an end contact formed thereon, and an insulating substrate disposed on the substrate such that a part of a peripheral edge thereof contacts the end contact. A tact metal plate having a dish-shaped portion capable of reversing operation curved so as to protrude away from the substrate, and covering 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, wherein the tact metal plate and the insulating cover member are joined via an adhesive, and the plate is pressed when the dish-shaped portion of the tact metal plate is pressed from outside the insulating cover member. A push-on switch in which a substantially central portion of the shape contacts the central contact and the central contact and the end contact are conducted. In the present invention, in order to solve the above-mentioned problem, two parts are used to hold the tact metal plate at a predetermined position by causing the deformation of the tact metal plate to follow the deformation of the tact metal plate in a portion corresponding to the tact metal plate of the insulating cover member. Are formed so as to be arranged at predetermined intervals. In this way, when the reversing operation of the tact metal plate is repeated, it is possible to prevent a situation in which the cuts of the two slits extend from the ends and are finally connected. When such a situation occurs , there arises a problem that the tact metal plate is easily moved.

In order to increase the click feeling, a configuration is adopted in which an overcoat is formed on a jumper line extending from the center contact, and a part of the peripheral portion of the tact metal plate is brought into contact with the overcoat. In this case, the amount of reversal of the tact metal plate increases. In such a case, if one of the two slits is formed so as to intersect the overcoat in an up-down relationship, the slit on the intersecting side is widened when not operating, and the slit on the non-intersecting side tends to close. As a result, there is a large difference in the joining force between the tact metal plate and the insulating cover member in the vicinity of the two slits, which hinders the following operation of the portion of the insulating cover member located between the two slits. Bonding between the portion and the tact metal plate is easily peeled off. On the other hand, when the insulating cover member is arranged on the substrate such that the overcoat is located between the two slits, the joining force between the tact metal plate and the insulating cover member near the two slits is large. There is no difference and such a problem does not occur.

When the two slits are formed so as to extend in parallel, the following operation of the portion of the insulating cover member located between the two slits becomes the smoothest.

[0010] The tact metal plate may be composed only of a dish-shaped portion, or may have a flange portion outside the dish-shaped portion.

[0011]

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

FIG. 1A is a schematic side view when the push-on switch according to one embodiment of the present invention is used in a portable stereo volume control circuit, and FIG. 1B is a schematic rear view thereof. . The FIG. 2 (A) Ri A-A line sectional view der of FIG. 1 (B), FIG. 2 (B) sectional view along line B-B der shown in FIG. 1 (B)
You. FIG. 3 is a plan view of a single switch shown using imaginary lines to explain the structure of the switch. In these figures, reference numeral 1 denotes 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 using a conductive paint such as copper foil, silver paint, or carbon. Although a circuit pattern is not shown in FIGS. 1A and 1B, as shown in FIGS. 2 and 3, the circuit pattern includes a contact pattern of a switch.
2 and 3, reference numeral 2 denotes a center contact, reference numeral 3 denotes an end contact, and reference numerals 4a and 4b denote jumper wires. An overcoat 5 is formed on the jumper wire 4b connected to the center contact 2 using an appropriate insulating material such as epoxy resin. In this embodiment, the thickness of the overcoat 5 is set to 5
The thickness is about 0 μm, which is about five times the average overcoat thickness (about 10 μm) used in a known switch. When a part of a tact metal plate, which will be described later, is placed on the thick overcoat 5, the click feeling increases. In FIG. 2 and FIG. 3, each part is somewhat exaggerated for easy understanding.

Reference numeral 6 denotes a tact metal plate formed of only a reversible dish-shaped portion curved so as to protrude in a direction away from the substrate 1. The tact metal plate 6 is placed on the substrate 1 such that a part of the peripheral edge 6 a is always in contact with the end contact 3. Reference numeral 7 denotes an insulating cover member having insulating properties and flexibility.
It can be formed using a 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 the present embodiment, two slits 8, 8 are formed in a portion corresponding to the tact metal plate 6 of the insulating cover member 7 so as to be arranged at a predetermined interval, and both ends of the slit 8 are tact. The metal plate 6 extends to a position beyond the peripheral edge 6a. 2 and 3, the gap width of the slits 8 is exaggerated, but these slits 8 are formed by cutting the insulating cover member 7 with a cutting tool. It is.

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 pressure-sensitive adhesive 9 may be any as long as it can adhere to the deformation of the insulating cover member 7 and the tact metal plate 6 to a certain extent without being cured and having tackiness and holding power. In this embodiment, FS is used as the adhesive 9.
An acrylic pressure-sensitive adhesive sold by K Corporation under the trade name of PL SIN was used. This pressure-sensitive adhesive is excellent in transparency, and re-joins to the joined object when a predetermined pressing force is applied again even after peeling.

The two slits 8, 8 are provided in the tact metal plate 6
The deformation of the insulating cover member 7 follows the deformation of the insulating cover member 7, and is provided as a deformation promoting groove for holding the tact metal plate at a predetermined position. The portion 7a of the insulating cover member 7 sandwiched between the two slits 8, 8 has a structure in which both ends are fixed to the substrate 1 with an adhesive 9, and has a high degree of freedom in deformation. Therefore, when the tact metal plate 6 is pressed and deformed, when the adhesive force or the holding force of the adhesive 9 is not so large, or when the holding force of the adhesive 9 is reduced due to aging, the outside of the slit 8 is formed. Even if the joint between the portion 7b of the insulating cover member 7 and the tact metal plate 6 may come off, the connection between the portion 7a and the tact metal plate 6 hardly comes off. In particular, as in the present embodiment, when the both ends of the slit 8 are sufficiently extended to positions beyond the peripheral edge 6a of the tact metal plate 6, the deformation of the portion 7a is facilitated. In addition, the air in the space formed between the tact metal plate 6 and the substrate 1 can be evacuated to the outside through a part of the slit 8, and air can be satisfactorily evacuated.

1A and 1B, reference numeral 10 denotes a push-on switch having the structure of the above embodiment,
Denotes a variable resistor, and 12 denotes an electronic component such as a transistor. Steps for assembling the circuit device of FIG. 1 will be described.

First, a circuit board 1 having a predetermined contact pattern on the back surface is manufactured. At least two concave portions or holes 1a for positioning are formed 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 positioning projections with the variable resistor 11 facing downward while inserting the holes 1a of the substrate 1 into the projections. Next, a tact metal plate 6 is attached to a portion of the insulating cover member 7 where the slit 8 is formed on the back surface of which the adhesive 9 is applied. Then, the surface of the insulating cover member 7 coated with the adhesive 9 is
On the back of The insulating cover member 7 includes the substrate 1
Positioning hole or concave portion 7 provided corresponding to hole 1a of
When the insulating cover member 7 is lowered toward the substrate 1 by fitting the concave portion 7c to the projection of the jig, the tact metal plate 6 is positioned on a predetermined contact pattern of the substrate 1. Can be. After placing the insulating cover member 7 on the substrate 1, a predetermined pressure is applied between the two to apply the insulating cover member 7
Is bonded 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, and 28 is a slit. When the tact metal plate 16 with the flange portion is used as in this embodiment, the positioning of the tact metal plate becomes easy. However, in this embodiment, notches 16C are formed on the outer peripheral edge of the flange portion 16B so as to correspond to the slits 28, so that air can be easily removed. Window portions 16D are formed so as to extend over the portion 16B. The notch 16C and the window 16D make air bleeding smoother. In the present embodiment, the slits 28, 28 are bent outward (broad-angle V-shape) so as to face the center. Thereby, 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 about five times the normal thickness as in the embodiments of FIGS. Thickness. With this configuration, a relatively large click feeling can be obtained by using a tact metal plate with a flange portion that tends to have a small click feeling compared to a tact metal plate having only a dish-shaped portion.

If the insulating cover member and the tact metal plate are joined with an adhesive, the insulating cover member can be deformed by following the tact metal plate. However, if the switch operation is frequently performed over a long period of time, the adhesiveness and adhesiveness of the adhesive may decrease, and a situation may occur in which the insulating cover member cannot be deformed by following the tact metal plate. is expected. Therefore, as in the present embodiment, two slits are formed in a portion corresponding to the tact metal plate of the insulating cover member so as to be arranged at a predetermined interval, and both ends of the slit are formed at the peripheral edge of the tact metal plate. Is extended to a position beyond the above, the portion of the insulating cover member located between the two slits is in a state where both ends are fixed. As compared with the case where the entire periphery is fixed without forming the slit, the degree of freedom of the portion where both ends are fixed between the slits is higher. Therefore, even when the switch operation is frequently performed over a long period of time, a part of the insulating cover member can reliably follow the deformation of the tact metal plate, and the tact metal plate can be held at a predetermined position. In addition, the slit also functions to release air, so that the operability of the switch is improved.
In particular, when a slit is formed, air can be smoothly vented through the slit.

Further, according to the present embodiment, by providing a deformation promoting groove including a slit in the insulating cover member, even when the switch operation is frequently performed for a long period of time, a part of the insulating cover member can be tact metal plate. The tact metal plate can be held in a predetermined position by reliably following the deformation of the tact metal plate. Also, since the tact metal plate and the insulating cover member are joined via an adhesive having an adhesive property, the insulating cover member can be deformed by following the tact metal plate, and the tact metal plate can be moved to a predetermined position. The switch operation can be reliably performed by reliably holding the switch.

[0021]

According to the present invention, two portions of the insulating cover member corresponding to the tact metal plate are made to follow the deformation of the tact metal plate so that the deformation of the insulating cover member follows the tact metal plate to hold the tact metal plate at a predetermined position. Since the slits are arranged at predetermined intervals, even if the tact metal plate is repeatedly turned over, the two slits may extend from the ends and eventually connect. Can be prevented from occurring.

When the insulating cover member is disposed on the substrate such that the overcoat is located between the two slits, there is a large difference in the joining force between the tact metal plate and the insulating cover member near the two slits. Does not occur, and the insulating cover member can be smoothly followed.

[Brief description of the drawings]

FIG. 1A is a side view of a circuit device provided with a push-on switch according to one embodiment of the present invention, and FIG.
It is a rear view of the apparatus of FIG.

Figure 2 (A) is Ri a sectional view along line A-A der in FIG. 1 (B),
FIG. 2B is a cross-sectional view taken along line BB of FIG.

FIG. 3 is a perspective view for explaining a configuration of a push-on switch according to one embodiment of the present invention.

FIG. 4 is a perspective view for explaining an embodiment in which the present invention is applied to a switch having a tact metal plate with a flange portion.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Circuit board 2 Center contact 3 End contact 5,15 Overcoat 6,16 Tact metal plate 6a Peripheral edge of tact metal plate 7 Insulation cover member 8,28 Slit 9 Adhesive 10 Push-on switch

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int.Cl. ⁷ , DB name) H01H 13/52 H01H 13/48

Claims (3)

(57) [Claims] An insulative substrate having a central contact and an end contact formed thereon, and a part of a peripheral portion is disposed on the substrate so as to abut the end contact, and faces in a direction away from the substrate. A tact metal plate having a dish-shaped portion capable of reversing operation curved so as to protrude, and covering the tact metal plate so as to hold the tact metal plate at a predetermined position on the insulating substrate. A fixed insulating cover member, wherein the tact metal plate and the insulating cover member are joined via an adhesive having an adhesive property, and the dish-shaped portion is pressed from outside the insulating cover member. And a push-on switch in which a substantially central portion of the dish-shaped portion is in contact with the center portion contact and the center portion contact and the end portion contact are conducted. A portion of the insulating cover member corresponding to the tact metal plate To Two slits for keeping the tact metal plate in a predetermined position by following the deformation of the insulating cover member to the deformation of the tact metal plate are formed so as to be arranged at a predetermined interval. Push-on switch. 2. An insulative substrate on which a center contact and an end contact and a jumper wire extending from the center contact are formed; an overcoat made of an insulating material formed on the jumper wire; A part is disposed on the substrate so as to abut on the end contact and the overcoat formed on the jumper line, and is capable of performing a reversing operation curved so as to protrude in a direction away from the substrate. A tact metal plate having a dish-shaped portion, and an insulating cover member fixed to the substrate so as to cover the tact metal plate so as to hold the tact metal plate at a predetermined position on the insulating substrate, The tact metal plate and the insulating cover member are joined via an adhesive, and when the dish-shaped portion is pressed from the outside of the insulating cover member, a substantially central portion of the dish-shaped portion is in contact with the central portion contact. In push-on switches with the central portion contact in contact with said end contact is conductive, said the portion corresponding to the tact metal plate of the insulating cover member deformation of the insulating cover member for deformation of the tact metal plate Two slits that follow and hold the tact metal plate at a predetermined position are formed so as to be arranged at a predetermined interval, and the insulating cover member is provided with the overcoat positioned between the two slits. A push-on switch that is arranged with respect to the substrate. 3. The push-on switch according to claim 1, wherein the two slits are formed so as to extend in parallel.