JP3283484B2 - Circuit device with 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 circuit device having 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 tact metal plate having a center contact and an end contact formed on an insulating substrate and having a dish-shaped portion capable of reversing operation, which is curved so as to protrude in a direction away from the substrate, is formed by dishing. 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.

It is another object of the present onset Ming, push-on switch and an insulating cover member and the tact metal plate when bonded with an adhesive, it is possible to reliably track the insulating cover member in the deformation of the tact metal plate It is to provide a circuit device provided with.

[0006]

SUMMARY OF THE INVENTION The present invention provides an insulating substrate on which a plurality of contact patterns including a center contact and an end contact are formed, and a plurality of contact patterns provided for each of the plurality of contact patterns.
A plurality of <br/> having a reversible operable dish-shaped portion that is disposed on the substrate so that a part of the peripheral portion is in contact with the end contact and is curved so as to protrude in a direction away from the substrate. > comprising tact metal plate, and an insulating cover member secured a plurality of tact metal plate to the substrate so as to cover the plurality of tact metal plate to retain in position on the insulating substrate, a plurality
The tact metal plate and the insulating cover member are joined via an adhesive, and when the dish-shaped portion of the tact metal plate is pressed from the outside of the insulating cover member, almost the center of the dish-shaped portion contacts the center contact. The present invention is directed to a push-on type switch circuit device in which a center contact and an end contact are in contact with each other to conduct. In the present invention, in order to solve the above problems, the parts corresponding to the plurality of Tak <br/> bets metal plate of the insulating cover member, to respectively follow the deformation of the insulation cover member in the deformation of the tact metal plate tact Two slits for holding the metal plate at a predetermined position are formed so as to be arranged at a predetermined interval. 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 edge 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.

If 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 smoothest.

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

[0010]

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

[0011] 1 (A) is a schematic side view of a case of using a plurality of flops Sshuon switch, the circuit device <br/> used in portable stereo volume control circuit, FIG. 1 (B) thereof schematic rear surface FIG. 2A is a cross-sectional view taken along line AA of FIG. 1B, and FIG. 2B is a cross-sectional view taken along line BB of FIG. 1B. 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. 1A and 1B do not show circuit patterns, but as shown in FIGS. 2 and 3, the circuit patterns include contact patterns of a plurality of switches. 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 about 50 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 which is curved so as to protrude 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 connected to 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.

In FIGS. 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. 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 a 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.

[0020]

According to the present invention, a plurality of insulating cover members are provided.
Forming two slits for holding the tact metal plate so as to follow the deformation of the insulation cover member in the deformation of the tact metal plate to the respective portions in a predetermined position corresponding to tact metal plate so arranged at a predetermined interval Therefore, even 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.

Further, when the insulating cover member is arranged 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 having a push-on switch according to an embodiment of the present invention, and FIG.
It is a rear view of the device of (A).

FIG. 2A is a sectional view taken along line AA of FIG. 1B;
FIG. 2B is a cross-sectional view taken along line BB of FIG.

FIG. 3 is a circuit provided with a push-on switch according to the present invention.
FIG. 2 is a perspective view for explaining a configuration of a main part of the device .

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 Continuation of the front page (56) References JP-A-1-100333 (JP, U) JP-A 1-119131 (JP, U) Patent 3010151 (JP, B2) (58) Fields investigated (Int. Cl. ⁷ , DB name) H01H 13/48 H01H 13/52

Claims (1)

(57) [Claims] A plurality of contacts comprising a center contact and an end contact.
An insulating substrate on which a point pattern is formed, and a direction in which a part of a peripheral portion is provided on the substrate so as to be in contact with the end contact and is separated from the substrate; wherein the plurality and a plurality of <br/> tact metal plate, to hold the plurality of tact metal plate in a predetermined position of the insulating substrate having an inverting operable dish curved so as to protrude toward the An insulating cover member fixed to the substrate so as to cover the tact metal plate, wherein the plurality of tact metal plates and the insulating cover member are joined via an adhesive having an adhesive property, 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 brought into contact with the center contact and a push-on switch in which the center contact and the end contact are conducted. Equipped circuit In, wherein the said portion corresponding to the plurality of tact metal plates of the insulating cover member, Taku deformation to the insulation by the deformation so as to follow the cover member of the plurality of each of the plurality of tact metal plate <br/> DOO metal circuit device provided with a push-on switch, characterized in that the two slits for holding the plate in position is formed in alignment at a predetermined interval.