JP2006108003A - Cover member for push-button switch, and push-button switch - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To contribute to thinness of an electronic equipment product such as a cellular phone. <P>SOLUTION: The push-button switch 1 is provided with the base material film 21 having a key top part formed by protruding upward, the core material part 22 formed inside the key top part, a pressing part 23 formed by protruding from the bottom face of the core material part 22 to the lower side, a circuit board 31 opposed arranged to the bottom face of the base material film 21, a fixed contact 32 arranged on the surface opposed to the base material film 21 of the circuit board 31, and a metallic plate spring member 33 for connecting/non-connecting two kinds of the fixed contacts 32a, 32b, and the bottom face of the core material part 22 is formed on the upper side than that of the base material film 21 by the distance d3, the bottom face of the base material film 21 and the bottom face of the pressing part 23 are formed on the approximately same plane, and the distance d1 between the bottom face of the base material film 21 and the surface opposed to the base material 21 of the circuit board 31 is almost the same as the movable distance d2 of the plate spring member. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a pushbutton switch cover member and a pushbutton switch used in an electronic device such as a cellular phone.

The following Patent Document 1 discloses a technique related to an injection mold for a molded article with a film. Moreover, a push button sheet of a cellular phone is exemplified as a molded product molded using the injection mold for molded product with film. This push button sheet has a plurality of protruding portions, that is, a plurality of key top portions, and the bottom surface of the core material forming the key top portions and the bottom surface of the base film are formed on the same plane. When such a pushbutton sheet is used for a pushbutton switch of a cellular phone, this pushbutton sheet is used in combination with a circuit board having a movable contact and a fixed contact. In this case, a protrusion for pressing the movable contact is further provided on the bottom surface of the core material of the pushbutton sheet.
JP 2003-181889 A

  By the way, when the protrusion is provided on the bottom surface of the core material described above, a gap corresponding to at least the height of the protrusion and the height of the movable contact is added between the bottom surface of the base film and the circuit board. It is necessary to provide it. This means that if the gap is set narrower than the combined height, the bottom surface of the base film will come into contact with the circuit board before the key top is pressed and the movable contact comes into contact with the fixed contact. caused by. In other words, the push button switch cannot perform the switching function unless a gap corresponding to at least the height of the protrusion and the height of the movable contact is provided between the bottom surface of the base film and the circuit board.

  On the other hand, electronic devices such as mobile phones are required to further reduce the thickness of products in order to improve convenience such as portability.

  Accordingly, an object of the present invention is to provide a pushbutton switch cover member and a pushbutton switch that can contribute to a reduction in the thickness of an electronic device product such as a mobile phone in order to solve the above-described problems.

  The cover member for a pushbutton switch of the present invention includes a base film having a key top portion that protrudes upward and a core portion formed inside the key top portion, and the bottom surface of the core portion is It is formed above the bottom surface of the substrate film.

  According to this invention, since the bottom surface of the core material portion is formed above the bottom surface of the base film, for example, even when the protrusion portion is further provided on the bottom surface of the core material portion, the protrusion portion It is possible to form the bottom surface of the upper portion by the amount on the upper side. Therefore, when this pushbutton switch cover member is applied to, for example, a pushbutton switch, the distance between the bottom surface of the base film and the substrate of the pushbutton switch can be further reduced. Thereby, it becomes possible to contribute to thickness reduction of electronic device products, such as a mobile telephone.

  In the cover member for a pushbutton switch according to the present invention, it is preferable that at least a central portion of the bottom surface of the core member is formed above the bottom surface of the base film.

  In this way, when the key top portion is pressed, the outer peripheral portion of the bottom surface of the core member portion can serve as a stopper that prevents the key top portion from being pushed too much and licked. The situation that the disc spring member is damaged can be prevented beforehand.

  The pushbutton switch cover member of the present invention further includes a protrusion formed to protrude downward from the bottom surface of the core portion, and the bottom surface of the base film and the bottom surface of the protrusion are formed on substantially the same plane. It is preferred that

  If it does in this way, it will become possible to form the bottom face of a projection part on the same plane as the bottom face of a substrate film. Therefore, when this pushbutton switch cover member is applied to, for example, a pushbutton switch, the distance between the bottom surface of the base film and the substrate of the pushbutton switch can be further reduced.

  In the cover member for a pushbutton switch of the present invention, the distance between the bottom surface of the base film and the substrate that can be disposed to face the bottom surface of the base film is two types of fixings that can be disposed on the substrate. It is preferable that the movable distance of the disc spring member for connecting / disconnecting the contact is substantially the same. Thereby, it becomes possible to narrow the space | interval of the bottom face of a base film, and a board | substrate to the movable distance of a disk spring member.

  In the push button switch cover member of the present invention, it is preferable that the height of the protrusion is equal to or greater than the movable distance of the disc spring member. Thereby, when a projection part is pushed down, the situation where the bottom face of a core part and a disc spring member contact can be prevented beforehand.

  In the pushbutton switch cover member of the present invention, it is preferable that the movable distance of the disc spring member is 0.15 to 0.20 [mm]. Thereby, the clearance gap provided between the bottom face of a base film and a board | substrate can be set to 0.15-0.20 [mm].

  In the cover member for a pushbutton switch according to the present invention, it is preferable that the bottom surface of the core member has a size including a disc spring member. Thereby, when the key top part is pressed, it is possible to prevent the bottom surface of the base film from coming into contact with the disc spring member.

  The pushbutton switch of the present invention is formed by projecting upward from a base film having a key top portion formed to protrude upward, a core material portion formed inside the key top portion, and a bottom surface of the core material portion. Two types of fixings included in the fixed contact portion, the fixed contact portion disposed on the surface of the substrate facing the base film, the fixed contact portion disposed on the surface facing the base film of the substrate A disc spring member for connecting / disconnecting the contact, and the bottom surface of the core part is formed above the bottom surface of the base film, and faces the bottom surface of the base film and the base film of the substrate The distance to the surface to be performed is substantially the same as the movable distance of the disc spring member.

  According to this invention, the distance between the bottom surface of the base film and the surface facing the base film of the substrate is formed by forming the bottom surface of the core part above the bottom surface of the base film. It can be designed to be almost the same as the movable distance of the disc spring member. Thereby, it becomes possible to contribute to thickness reduction of electronic device products, such as a mobile telephone.

  According to the push button switch cover member and the push button switch according to the present invention, it is possible to contribute to a reduction in thickness of an electronic device product such as a mobile phone.

  DESCRIPTION OF EMBODIMENTS Hereinafter, embodiments of a push button switch cover member and a push button switch according to the present invention will be described with reference to the drawings. In addition, in each figure, the same code | symbol is attached | subjected to the same element and the overlapping description is abbreviate | omitted.

  First, a push button switch according to the present embodiment will be described with reference to FIG. FIG. 1 is a cross-sectional view of a pushbutton switch 1 for a mobile phone applied to a mobile phone. The push button switch 1 is roughly divided into a push button switch cover member 2 and a substrate member 3. Note that C in the figure is a cover case of the mobile phone.

  The pushbutton switch cover member 2 includes a base film 21 and a core member 22. The base film 21 has a key top portion that protrudes upward. On the top surface of the key top portion, for example, a display portion on which characters, numbers, symbols, symbols and the like are printed and displayed is provided. The core member 22 is formed of a hard resin filled inside the key top portion. The bottom surface of the core member 22 preferably has a size that includes a metal disc spring member 33 described later. As a result, it is possible to prevent the bottom surface of the base film 21 from coming into contact with the metal disc spring member 33 when the key top portion is pressed, thereby improving the durability and stability of the circuit. be able to. Near the center of the bottom surface of the core member 22, a pressing portion 23 (protrusion) is integrally formed with the core member 22. That is, the pressing portion 23 is formed to protrude downward from the bottom surface of the core portion 22. The pressing portion 23 is a member provided to press a metal disc spring member 33 described later.

  The board member 3 includes a circuit board 31, fixed contacts 32a and 32b, and a metal disc spring member 33 serving as a movable contact for connecting / disconnecting the fixed contact 32a and the fixed contact 32b. The metal disc spring member 33 is directly fixed to the bottom surface of the pressing portion 23 with an adhesive. The thickness of the metal disc spring member 33 in this embodiment is about 0.04 [mm], and the stroke (movable distance) of the metal disc spring member 33 is about 0.15 to 0.20 [mm]. is there. The fixed contacts 32 a and 32 b and the metal disc spring member 33 are not necessarily included in the substrate member 3 and may be configured as contact members independent from the substrate member 3.

  In the pushbutton switch 1 configured as described above, the bottom surface of the core portion 22 of the pushbutton switch cover member 2 is formed above the bottom surface of the base film 21 by a distance d3. Thereby, the bottom face of the pressing part 23 can be formed on the upper side by the distance d3. Accordingly, the distance d1 between the bottom surface of the base film 21 and the circuit board 31 can be further reduced. Thereby, it becomes possible to contribute to thickness reduction of a mobile telephone.

  Further, by forming the bottom surface of the pressing portion 23 above the bottom surface of the base film 21 by the thickness of the metal disc spring member 33 and the thickness of the fixed contact 32a, the distance d1 is made of metal. The stroke d2 of the disc spring member 33 can be the same. By the way, the circuit cannot be conducted unless the distance d1 is designed to be at least the stroke d2. Therefore, in the present embodiment, 0.15 [mm], which is the minimum value of the stroke d2, is the minimum value that can be taken as the interval d1. In this case, the thickness of the mobile phone using the push button switch 1 can be made the thinnest.

  In addition, by making the distance d1 the same as the stroke d2, it is possible to prevent the key top portion from being pushed excessively and licked. That is, in this case, the bottom surface of the base film 21 plays a role as a stopper, and prevents the situation where stress is dispersed on the bottom surface serving as the stopper and the metal disc spring member 33 is damaged. Can do.

  Here, in general, the thickness of the metal disc spring member 33 and the thickness of the fixed contact 32 a are very small compared to the height of the metal disc spring member 33. It is also possible to design without considering the thickness of the fixed contact 32a and the thickness of the fixed contact 32a. Therefore, considering such a case, by forming the bottom surface of the base film 21 and the bottom surface of the pressing portion 23 on substantially the same plane, the distance d1 is set to the stroke d2 of the metal disc spring member 33. Can be almost identical. In the case of strict design, when the bottom surface of the base film 21 and the bottom surface of the pressing portion 23 are formed on the same plane, the distance d1 is equal to the height of the metal disc spring member 33 (stroke d2 + metal plate). The distance obtained by adding the thickness of the spring member 33 and the thickness of the fixed contact 32a.

  Moreover, it is preferable to design the height of the pressing portion 23 to be equal to or greater than the stroke d2 of the metal disc spring member 33. Thereby, when the key top portion is pressed, the bottom surface of the core member portion 22 can be prevented from coming into contact with the metal disc spring member 33, and the durability and stability of the circuit can be improved. Can do.

  In the pushbutton switch 1 configured as described above, when the key top portion is pressed, the pressing portion 23 presses the metal disc spring member 33. The metal disc spring member 33 is buckled by this pressing force (usually approximately 1.0 to 3.0 [N]). The fixed contact 32a and the fixed contact 32b are connected by the buckled metal disc spring member 33, and the push button switch 1 is turned on. When the pressing of the key top portion is released, the metal disc spring member 33 returns. As a result, the fixed contacts 32a and 32b connected by the metal disc spring member 33 are opened (not connected), and the push button switch 1 is turned off.

[Example]
Next, examples of the present invention will be described.

  First, letters, numbers, symbols, designs, etc. are printed on a portion corresponding to the top surface of the key top portion of the polycarbonate film 21 having a thickness of 125 μm to form a display portion.

  Next, the film 21 is set on the concave mold side of the mold cut into a key shape, and press-molded under conditions of a mold temperature of 120 ° C. and a molding time of 15 seconds. Thereby, the base film 21 with a total height of 1.5 mm is obtained.

  Next, the core part 22 is formed inside the key top part of the base film 21. The core part 22 is formed by injection molding. Specifically, a polycarbonate resin (Iupilon / Mitsubishi Engineering Plastics Co., Ltd.) is melted by heat using a pressing portion 23 with a height of 0.2 mm provided on the bottom surface of the core material portion 22 as a gate, and a key top. It is injected into the inside of the part, and then cooled individually in the mold. At the time of injection, the bottom surface of the core member 22 is formed 1.3 mm above the bottom surface of the base film 21. Thereby, the cover member 2 for pushbutton switches is obtained.

  Next, a silicone-based moisture-curing adhesive Super X8008 (made by Cemedine Co., Ltd.) is applied to a metal disc spring member 33 (diameter 4.5 mm, height 0.20 mm, thickness 0.04 mm, stroke 0.16 mm). Apply and stick to the bottom of the pressing part 23. Thereby, the member for pushbutton switches of 1.7 mm in total height is obtained. The push button switch 1 is obtained by attaching the circuit board 31 having the fixed contacts 32a and 32b to the push button switch member.

[Modification]
The pushbutton switch and the pushbutton switch cover member according to the present invention are not limited to the pushbutton switch 1 and the pushbutton switch cover member 2 shown in FIG. 1, and other various pushbutton switches and pushbutton switch cover members can be used. Applicable. For example, the present invention can also be applied to the push button switch 1 and the push button switch cover member 2 shown in FIG. The push button switch 1 shown in FIG. 2 is different from the push button switch 1 shown in FIG. 1 in that a press sheet 24 and a metal dome sheet 34 are provided below the core portion 22. The pressing sheet 24 is made of elastomer and has a waterproof function. The pressing sheet 24 is formed with a pedestal portion 24a for concentrating stress when the key top portion is pressed, and a pressing portion 24b (protruding portion) for pressing the metal disc spring member 33. . The height of the pressing portion 24 b is designed in consideration of the stroke of the metal disc spring member 33 and the compression of the pressing sheet 24. The metal dome sheet 34 is an adhesive sheet for arranging and fixing the metal disc spring member 33 (metal dome).

  Further, for example, the present invention is also applicable to the push button switch 1 and the push button switch cover member 2 shown in FIG. The push button switch 1 shown in FIG. 3 is different from the push button switch 1 shown in FIG. 1 in that the outer peripheral portion 22a of the bottom surface of the core material portion 22 is formed on substantially the same plane as the bottom surface of the base film 21. Is different. As described above, the push button switch 1 shown in FIG. 3 is characterized in that, of the bottom surface of the core member 22, the central portion excluding the outer peripheral portion 22 a is formed above the bottom surface of the base film 21. is there. By forming such an outer peripheral part 22a, it becomes possible for the outer peripheral part 22a to play a role as a stopper for preventing the key top part from being pushed excessively and being licked, and the stopper provided on the bottom surface of the base film 21 described above. The role as can be further improved.

It is sectional drawing of the pushbutton switch in embodiment. It is sectional drawing of the pushbutton switch in a modification. It is sectional drawing of the pushbutton switch in a modification.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 ... Pushbutton switch, 2 ... Cover member for pushbutton switches, 21 ... Base film, 22 ... Core material part, 22a ... Outer peripheral part of core material part, 23 ... Pressing part 24 ... Pressing sheet, 24b ... Pressing part, 24a ... Pedestal part, 3 ... Board member, 31 ... Circuit board, 32a, 32b ... Fixed contact, 33 ... Metal Plate spring member, 34 ... metal dome sheet.

Claims (8)

A base film having a key top formed to project upward;
A core part formed inside the key top part,
The cover member for a push button switch, wherein a bottom surface of the core member is formed above a bottom surface of the base film. The pushbutton switch cover member according to claim 1, wherein at least a central portion of the bottom surface of the core member portion is formed above the bottom surface of the base film. Further comprising a protrusion formed to protrude downward from the bottom surface of the core part,
3. The pushbutton switch cover member according to claim 1, wherein a bottom surface of the base film and a bottom surface of the protrusion are formed on substantially the same plane. A dish for connecting / disconnecting two types of fixed contacts in which the distance between the bottom surface of the base film and the substrate that can be disposed opposite to the bottom surface of the base film is disposed on the substrate The pushbutton switch cover member according to any one of claims 1 to 3, wherein the movable distance of the spring member is substantially the same. 5. The pushbutton switch cover member according to claim 4, wherein a height of the protrusion is equal to or greater than a movable distance of the disc spring member. 5. The pushbutton switch cover member according to claim 4, wherein the movable distance of the disc spring member is 0.15 to 0.20 [mm]. The pushbutton switch cover member according to any one of claims 4 to 6, wherein a bottom surface of the core member has a size including the disc spring member. A base film having a key top formed to project upward;
A core part formed inside the key top part;
A protrusion formed to protrude downward from the bottom surface of the core material;
A substrate disposed to face the bottom surface of the base film;
A fixed contact portion disposed on a surface of the substrate facing the base film;
A disc spring member for connecting / disconnecting two types of fixed contacts included in the fixed contact portion,
The bottom surface of the core part is formed above the bottom surface of the base film,
The push button switch, wherein a distance between a bottom surface of the base film and a surface of the substrate facing the base film is substantially the same as a movable distance of the disc spring member.

Images