JP2019053899A - Dome type switch - Google Patents

Abstract

To provide a dome type switch which has excellent operation feeling and can be inexpensively constituted.SOLUTION: Disclosed is a dome type switch formed by having: a printed circuit board 20 having at least a structure 21, a conductor layer 22 and an insulation layer 23; dome contacts 30 mounted on a printed circuit board 20; and an adhesive sheet 40 which covers the dome contacts 30 and fixes the dome contacts 30 to the printed circuit board 20. In the printed circuit board 20, a groove (27') is formed, made of a conductor layer 22 and a patterned lack part of an insulation layer 23. A ventilation passage 52 for releasing air in the inside of the dome contacts 30 to the outside is constituted by putting a lid on the groove (27') using the adhesive sheet 40.SELECTED DRAWING: Figure 3

Description

  The present invention relates to a dome-type switch having a dome contact that reverses when pressed.

  FIG. 8 shows a configuration described in Patent Document 1 as a conventional example of this type of dome type switch.

  An annular wiring pattern 12 is provided on the surface of the substrate 11, and a wiring pattern 13 that is separated from the wiring pattern 12 and is located inside the wiring pattern 12. A dome shape is formed on the surface of the substrate 11, A dome contact (referred to as a key switch diaphragm in Patent Document 1) 14 made of a thin metal plate having flexibility and conductivity is placed. The dome contact 14 is placed so that the peripheral edge always contacts the wiring pattern 12.

  The dome contact 14 and the substrate 11 are covered with a cover film 15, and the dome contact 14 is held by the cover film 15 so as not to shift in a direction along the surface of the substrate 11.

  A sealed space 16 is provided on the back surface of the substrate 11, and a space surrounded by the substrate 11 and the dome contact 14 and the sealed space 16 are connected by a through hole 17 provided in the substrate 11. The sealed space 16 is formed by the substrate 11, a substrate 18 provided in parallel with the substrate 11 on the back side of the substrate 11, and an adhesive 19 that adheres and fixes the substrate 11 and the substrate 18 to each other.

  According to this dome-type switch (referred to as a key switch in Patent Document 1), when the dome-type switch is pressed, part of the air in the space surrounded by the dome contact 14 and the substrate 11 is sealed space. Therefore, the increase in the atmospheric pressure in the space surrounded by the dome contact 14 and the substrate 11 can be suppressed sufficiently low, and a good click feeling can be obtained.

JP 2004-39340 A

  As described above, the conventional dome type switch shown in FIG. 8 has a good operation feeling (click feeling) because the air inside the dome contact 14 escapes to the outside when pressed. However, the substrate 11 is provided with a through-hole 17 and further uses a substrate 18 other than the substrate 11 for mounting the dome contact 14 or an adhesive 19 for fixing the substrate 18. In addition, the number of parts increased and the cost was high.

  In view of this problem, the object of the present invention is to form an air passage for escaping the air inside the dome contact to the outside without requiring additional members or additional man-hours, and thus has a good operation feeling, and An object of the present invention is to provide a dome type switch that can be configured at low cost.

  According to the first aspect of the present invention, a printed circuit board having at least a base material, a conductor layer, and an insulating layer, a dome contact mounted on the printed circuit board, and an adhesive that covers the dome contact and fixes the dome contact to the printed circuit board. In a dome-type switch having a sheet, a groove is formed on the printed circuit board by a patterned notched portion of the conductor layer and the insulating layer, and the groove is covered with an adhesive sheet so that the air inside the dome contact is removed. An air passage for escape to the outside is configured.

  In the invention of claim 2, in the invention of claim 1, the printed circuit board further includes a silk printing layer, and the groove is formed by a patterned notched portion of the conductor layer, the insulating layer, and the silk printing layer.

  According to the invention of claim 3, in the invention of claim 1 or 2, the air passage is not communicated with the outside air.

  According to a fourth aspect of the present invention, in the third aspect of the present invention, the air passage is communicated with the internal space of another dome contact mounted on the printed board and different from the dome contact.

  According to a fifth aspect of the present invention, in the third aspect of the present invention, the air passage is communicated with an air reservoir formed on the printed circuit board.

  According to a sixth aspect of the present invention, in the fifth aspect of the present invention, the air reservoir is formed by extending an air passage.

  According to the present invention, when the dome-type switch is pressed, the air passage for escaping the air inside the dome contact to the outside is configured without requiring additional members or additional man-hours. A dome-shaped switch having a simple operation feeling can be configured at low cost.

The top view which shows the external appearance of Example 1 of the dome shape switch by this invention. The top view which shows the state which removed the adhesive sheet from the state shown in FIG. The AA line expanded sectional view of FIG. A is a plan view of the printed circuit board in FIG. 2, B is an enlarged sectional view taken along line DD of A, and C is an enlarged sectional view taken along line E-E of A. FIG. The figure for demonstrating the structure of Example 2 of the dome shape switch by this invention. FIG. 6 is an enlarged cross-sectional view of Embodiment 2 of the dome-shaped switch according to the present invention, taken along line AA in FIG. 5. FIG. 6A is a plan view of the printed circuit board in FIG. 5, and FIG. Sectional drawing which shows the prior art example of a dome shape switch.

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

  FIG. 1 shows the appearance of a dome type switch according to Embodiment 1 of the present invention. In FIG. 1, two dome type switches are provided side by side. In this example, the dome-shaped switch 100 includes a printed circuit board 20, a dome contact 30 (not visible in FIG. 1), and an adhesive sheet 40.

  FIG. 2 shows a state where the adhesive sheet 40 is removed from the state shown in FIG. 1, and FIG. 3 shows a cross-sectional structure of the two dome type switches 100 shown in FIG. FIG. 4 shows the configuration of the printed circuit board 20. First, the configuration of the printed circuit board 20 will be described with reference to FIG.

  In this example, the printed circuit board 20 has a conductor layer 22, an insulating layer 23, and a silk print layer 24 on the front surface 21 a side of the base material 21, and has a conductor layer 25 on the back surface 21 b side of the base material 21. .

  The conductor layer 22 located on the surface 21a of the substrate 21 is made of copper foil, and the conductor layer 22 made of copper foil formed on the entire surface 21a is patterned by etching to form a predetermined pattern. In this example, two circular first electrodes 22a for two dome-shaped switches 100 are formed separately from surrounding conductor layers 22 by grooves 26, and further surround these two first electrodes 22a. The conductor layer 22 has grooves 27 formed by etching away the copper foil so that the annular grooves 26 around the respective first electrodes 22a communicate with each other.

  The insulating layer 23 is formed on the conductor layer 22 by patterning a resist, for example. The insulating layer 23 is formed on the conductor layer 22 except for the annular region of the conductor layer 22 surrounding each first electrode 22a and the first electrode 22a located inside thereof, and is exposed surrounding the first electrode 22a. The annular region of the conductor layer 22 forms the second electrode 22b of the dome type switch 100.

  The silk print layer 24 is formed on the insulating layer 23. Silk printing is used, for example, to represent characters and symbols on a printed board. In this example, the silk printing layer 24 pattern as shown in FIG. 4 is formed by this silk printing. The pattern of the silk print layer 24 includes an annular portion 24a that surrounds each second electrode 22b, and a pair of linear portions 24b that extend in parallel with the groove 27 on both sides of the groove 27 of the conductor layer 22 and connect the two annular portions 24a. It becomes more.

  As described above, the conductor layer 22, the insulating layer 23, and the silk print layer 24 are sequentially patterned and laminated on the surface 21 a of the base material 21, thereby forming the groove 27 portion formed in the conductor layer 22. The cross section has the structure shown in FIG. 4B, that is, the depth corresponding to the total thickness of the conductor layer 22, the insulating layer 23, and the silk print layer 24 (about 0.1 mm) excluding the portion crossing the second electrode 22b. A groove 27 ′ having is formed.

  In FIG. 4B, the end surfaces of the insulating layer 23 and the silk print layer 24 are sequentially retreated slightly in the direction in which the width of the groove 27 ′ increases with respect to the end surface of the conductor layer 22 constituting the inner wall surface of the groove 27 ′. With such a configuration, it is possible to prevent the insulating layer 23 and the silk print layer 24 from dropping on the surface 21a of the base member 21 due to, for example, printing misalignment.

  In the configuration described above, the circular first electrode 22a serves as a signal electrode of the dome-shaped switch 100, and the annular second electrode 22b surrounding the first electrode 22a serves as a ground (GND) electrode. As shown in FIG. 4C, the first electrode 22a is connected to the back-side electrode 25a formed by the conductor layer 25 on the back surface 21b side of the substrate 21 through a pair of filled via holes 28.

  Two dome-shaped dome contacts 30 having elasticity and conductivity and made of a thin metal plate are mounted on the printed circuit board 20 configured as described above, as shown in FIG. And the adhesive sheet 40 is affixed so that the printed circuit board 20 may be covered, and the dome shape switch 100 shown in FIG.1 and FIG.3 is completed. As shown in FIG. 3, the periphery of the dome contact 30 is placed on the second electrode 22 b and is positioned and fixed on the printed circuit board 20 by the adhesive sheet 40. For example, the adhesive sheet 40 is printed on a PET (polyethylene terephthalate) sheet.

  The groove 27 ′ formed in the printed circuit board 20 is covered with an adhesive sheet 40, and in this example, as shown in FIG. 3, an air passage 52 that communicates the internal space 51 of the two dome contacts 30 is configured. Has been.

  In the dome-type switch 100 having the above-described configuration, when the dome contact 30 is pushed down via the adhesive sheet 40, the dome contact 30 is reversed and the top portion contacts the first electrode 22a, thereby the first electrode 22a. The second electrode 22b is conducted through the dome contact 30 and the switch is turned on. On the other hand, when the pressing (pressing) on the dome contact 30 is released, the dome contact 30 is elastically restored to the original state, and the switch is turned off.

  In order to obtain a good operational feeling, when the dome contact 30 is reversed, it is necessary to release the air in the internal space 51 of the dome contact 30 to the outside. In this example, the internal spaces 51 of the two dome contacts 30 are communicated. Since the air passage 52 is formed, air in the internal space 51 of the dome contact 30 escapes (flows in) into the internal space 51 of the other dome contact 30 through the air passage 52, so that the pressed dome is operated. An increase in the atmospheric pressure of the internal space 51 of the contact 30 can be suppressed sufficiently low, and thus a good operational feeling can be obtained.

  As described above, in this example, the groove 27 ′ formed by the patterned notched portions of the conductor layer 22, the insulating layer 23, and the silk print layer 24 is formed in the printed board 20, and the groove 27 ′ is formed by the adhesive sheet 40. A ventilation path 52 is formed for covering and releasing the air inside the dome contact 30 to the outside. The groove 27 ′ constituting the air passage 52 uses a constituent layer of the printed circuit board 20 and is formed at the same time in a normal manufacturing process of the printed circuit board 20, and the adhesive sheet 40 attaches the dome contact 30 to the printed circuit board 20. Since it is fixed, no additional members or additional man-hours are required. Therefore, according to this example, a dome-shaped switch having a good operation feeling can be configured at low cost.

  In the above-described example, two dome-type switches 100 are provided. However, when three or more dome-type switches 100 are provided, for example, an air passage 52 is provided between the dome-type switches 100. It is formed. Further, the number of ventilation paths 52 provided in one dome type switch 100 is not limited to one, and a plurality of ventilation paths 52 may be provided toward a plurality of adjacent dome type switches 100.

  In the first embodiment, when a plurality of dome type switches 100 are provided, the configuration in which the internal space 51 of the adjacent dome contact 30 communicates with the air passage 52 through the air passage 52 is described. However, the dome type switch is provided alone. In such a case, such a configuration cannot be adopted. In the second embodiment, a configuration in the case where a dome type switch exists alone will be described.

  FIG. 5 shows the configuration of the dome-shaped switch of Example 2 with the adhesive sheet omitted, and FIG. 6 shows the cross-sectional structure of the dome-shaped switch shown in FIG. It is a thing. FIG. 7 shows the configuration of the printed circuit board 20 'in FIG. First, the configuration of the printed circuit board 20 'according to the second embodiment will be described with reference to FIG. Note that portions corresponding to the printed circuit board 20 illustrated in FIG. 4 are denoted by the same reference numerals, and detailed description thereof is omitted.

  In this example, a groove 27 ′ is formed on the printed circuit board 20 ′ in the same manner as the printed circuit board 20, but the front end of the groove 27 ′ (the front end opposite to the first electrode 22a side) is formed on the printed circuit board 20 ′. It is the structure connected to the recessed part 29. The concave portion 29 is formed by a patterned cut-out portion of the conductor layer 22, the insulating layer 23, and the silk print layer 24 as in the groove 27 ′. It has a depth corresponding to the total thickness. In this example, the concave portion 29 is stretched on a circumference concentric with the annular second electrode 22b to form a semicircular arc shape, and the width of the concave portion 29 is larger than the width of the groove 27 ′. . In this example, the silk print layer 24 is provided on the entire surface of the insulating layer 23.

  As shown in FIG. 5, a dome contact 30 is mounted on the printed circuit board 20 ′, and an adhesive sheet 40 is attached so as to cover the dome contact 30 and the printed circuit board 20 ′, thereby having the structure shown in FIG. The dome type switch 200 is completed.

  The groove 27 ′ formed on the printed circuit board 20 ′ is covered with the adhesive sheet 40 to form the air passage 52 as in the first embodiment, and the recess 29 formed on the printed circuit board 20 ′ is formed with the adhesive sheet 40. The air reservoir 53 is configured by being covered.

  In this example, the air passage 52 communicating with the internal space 51 of the dome contact 30 is configured to communicate with an air reservoir 53 formed on the printed circuit board 20 ′ by extending the air passage 52. When the dome-type switch 200 is pressed and the dome contact 30 is reversed, the air in the internal space 51 of the dome contact 30 escapes to the air reservoir 53 through the air passage 52.

  The air reservoir 53 has a volume capable of receiving air in the internal space 51 so as to suppress an increase in the atmospheric pressure of the internal space 51 when the dome contact 30 is reversed.

  The formation of the air pool 53 does not require an additional member or an additional man-hour as in the case of the air passage 52. Therefore, according to the configuration of the second embodiment, it is favorable even when a dome-type switch is present alone. A dome-type switch having an operation feeling can be configured at low cost.

  Although the embodiment of the present invention has been described above, the air passage 52 communicates the internal spaces 51 of the dome contact 30 that is a closed space in the first embodiment, and the air that is a closed space in the second embodiment. The reservoir 53 and the internal space 51 of the dome contact 30 are communicated with each other. That is, in the first and second embodiments, the air passage 52 is configured not to communicate with the outside air. Therefore, if such a configuration is adopted, the first and second electrodes 22a and 22b of the dome contact 30 are exposed through the air passage 52 when the outside air derived from the use environment, for example, oil mist or hydrogen sulfide is passed through. It is possible to avoid the occurrence of problems such as entering the inner space 51 and causing a contact failure.

  The present invention is characterized in that the air passage for escaping the air inside the dome contact 30 to the outside is constructed without requiring additional members or additional man-hours. It does not have to be in communication with.

  In the first and second embodiments, the printed boards 20 and 20 ′ are both silk-printed, and the groove 27 ′ in the first embodiment and the groove 27 ′ in the second embodiment are the same as the thickness of the silk print layer 24. However, if the printed circuit board is not silk-printed, it is not necessary to provide the silk-printed layer 24 for increasing the depth of the grooves 27 ′ and the recesses 29.

  If the silk print layer 24 is formed not only on the side edges (peripheries) of the grooves 27 ′ and the recesses 29 but also around the second electrode 22 b as shown in the first and second embodiments, the dome contact 30. The adhesiveness of the adhesive sheet 40 for positioning and fixing the printed circuit board around the dome contact 30 can be further enhanced.

DESCRIPTION OF SYMBOLS 11 Board | substrate 12,13 Wiring pattern 14 Dome contact 15 Cover film 16 Sealed space 17 Through-hole 18 Board | substrate 19 Adhesive 20,20 'Printed circuit board 21 Base material 21a Front surface 21b Back surface 22 Conductive layer 22a 1st electrode 22b 2nd electrode 23 Insulation Layer 24 Silk printing layer 24a Annular portion 24b Linear portion 25 Conductor layer 25a Back side electrode 26, 27, 27 'Groove 28 Filling via hole 29 Recess 30 Dome contact 40 Adhesive sheet 51 Internal space 52 Ventilation path 53 Air reservoir 100, 200 Dome type switch

Claims (6)

A printed circuit board having at least a base material, a conductor layer, and an insulating layer; a dome contact mounted on the printed circuit board; and an adhesive sheet that covers the dome contact and fixes the dome contact to the printed circuit board. A dome-shaped switch,
The printed circuit board is formed with a groove formed by a patterned portion of the conductor layer and the insulating layer,
A dome-shaped switch, wherein the groove is covered with the adhesive sheet to form an air passage for escaping air inside the dome contact to the outside. The dome type switch according to claim 1,
The printed circuit board further comprises a silk print layer;
The dome-shaped switch, wherein the groove is formed by a patterned cutout portion of the conductor layer, the insulating layer, and the silk print layer. The dome type switch according to claim 1 or 2,
The dome-type switch, wherein the air passage is not in communication with outside air. The dome type switch according to claim 3,
The dome-shaped switch is characterized in that the air passage communicates with an internal space of another dome contact mounted on the printed board and different from the dome contact. The dome type switch according to claim 3,
The dome-type switch, wherein the air passage is in communication with an air pocket formed on the printed circuit board. The dome type switch according to claim 5,
The dome type switch characterized in that the air reservoir is constituted by an extension of the air passage.

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