The present disclosure relates to a switch case and a switch used for an operation unit of various electronic devices.
In recent years, various electronic devices have become smaller, lighter, and thinner. Along with these trend, a switch used for an operation unit of an electronic device has also been strongly demanded to become smaller and thinner.
For example, as shown in Unexamined Japanese Patent Publication No. 2011-60627, in the conventional switch, a switch case is formed by molding (insert molding) a case made of insulating synthetic resin in such a manner as to embed a metal member. The central fixed contact of the switch is constituted by a part of the metal member exposed from the inner bottom surface of the opening of the case. In addition, a portion different from the central fixed contact of the metal member protrudes outward from the side surface of the case. This portion constitutes a terminal.
The present disclosure provides a switch case that suppresses infiltration of water and flux into the switch case while being a thin type, and a switch that uses the switch case.
The switch case of the present disclosure includes a metal plate having a first surface and a second surface that is at a side opposite to the first surface, and a resin case embedding a part of the metal plate. The resin case includes a housing portion having an opening disposed on a surface of the resin case. The metal plate includes a terminal portion, a contact portion, and an intermediate portion positioned between the terminal portion and the contact portion. The terminal portion is exposed from the surface of the resin case. The intermediate portion is embedded in the resin case, and the intermediate portion is provided with first and second through-holes each penetrating the first surface and the second surface. A hole diameter of the first through-hole at the second surface is larger than a hole diameter of the first through-hole at the first surface.
According to the switch case of the present disclosure, the resin case comes into close contact with the metal plate more firmly. Therefore, the infiltration of water or flux into the housing portion from a gap between the resin case and the terminal portion can be suppressed.
Prior to the description of the exemplary embodiment of the present disclosure, problems of the conventional switch case will be described.
In the conventional switch, when a small switch case is used, water and flux tend to infiltrate into the switch case through a slight gap between the resin member and the terminal.
In the following, an exemplary embodiment of the present disclosure will be described with reference to the accompanying drawings.
As shown in
Metal plate 30 has first surface 30A, and second surface 30B that is at a side opposite to first surface 30A. A part of metal plate 30 is embedded in resin case 20. Specifically, resin case 20 is formed on a surface of metal plate 30 by insert molding. Metal plate 30 includes first terminal portion 31, first contact portion 33, and first intermediate portion 32 positioned between first terminal portion 31 and first contact portion 33. Hereinafter, first terminal portion 31 is referred to as terminal portion 31, first intermediate portion 32 is referred to as intermediate portion 32, and first contact portion 33 is referred to as contact portion 33.
Terminal portion 31 is exposed from an outer surface of resin case 20. Intermediate portion 32 is embedded in resin case 20. Contact portion 33 includes a part of first surface 30A exposed to housing portion 21.
In intermediate portion 32, through-hole 52 penetrating from first surface 30A to second surface 30B is formed. In through-hole 52, hole diameter B at second surface 30B is larger than hole diameter A at first surface 30A. Since resin constituting resin case 20 is filled in through-hole 52, resin case 20 comes into close contact with metal plate 30 more firmly. Then, the infiltration of water or flux into housing portion 21 from the gap between resin case 20 and terminal portion 31 is suppressed.
In the following, switch case 101 will be described in detail.
In switch case 101, similarly to metal plate 30, metal plate 40 has first surface 40A, and second surface 40B at the side opposite to the first surface. Similarly to metal plate 30, metal plate 40 includes second terminal portion 41, second contact portion 43, and second intermediate portion 42 positioned between second terminal portion 41 and second contact portion 43. Hereinafter, second terminal portion 41 is referred to as terminal portion 41, second intermediate portion 42 is referred to as intermediate portion 42, and second contact portion 43 is referred to as contact portion 43.
In switch case 101, insulating resin case 20 is formed on metal plates 30, 40 by insert molding.
The shape of resin case 20 is, for example, a rectangular parallelepiped box. Resin case 20 has, for example, upper surface 20A, and bottom surface 20B disposed at a side opposite to upper surface 20A. Resin case 20 is provided with housing portion 21 having opening 21A formed on upper surface 20A. Housing portion 21 has a columnar cavity. In housing portion 21, bottom portion 21B is formed at an opposite end of opening 21A.
It should be noted that pin hole 20C may be blocked in order to prevent the infiltration of water or flux. The specific method for blocking pin hole 20C includes forming resin case 20 by insert molding then subsequently forming resin case 20 by insert molding again separately. That is, using a method such as twice molding allows a switch case, in which exposed portions 30C, 40C are not formed, to be manufactured.
Next, metal plates 30, 40 will be described in detail.
Each of metal plates 30, 40 is obtained by forming a thin metal plate having thickness T of, for example, from 30 μm to 100 μm, inclusive, so as to have a predetermined shape. In each of metal plates 30, 40, predetermined portions are bent to be formed.
Metal plate 30 is formed in a U shape as an example. Each of a pair of tips in the U shape constitutes terminal portion 31. An end opposite to terminal portion 31 constitutes contact portion 33. Metal plate 40 is formed in a Y shape as an example. A pair of ends branched in the Y shape constitute terminal portions 41. An end opposite to terminal portions 41 constitutes contact portion 43.
Each of intermediate portions 32, 42 is embedded in resin case 20. In metal plates 30, a surface including a portion exposed from bottom portion 21B to housing portion 21 is defined as first surface 30A. In metal plates 40, a surface including a portion exposed from bottom portion 21B to housing portion 21 is defined as first surface 40A. Contact portion 33 has a part of first surface 30A and constitutes a contact for electrically connecting with movable member 22. Contact portion 43 has a part of first surface 40A and constitutes a contact for electrically connecting with movable member 22.
It should be noted that as shown in
It should be noted that structural portions 50 formed in each of metal plates 30, 40 have the same function and structure as each other. Structural portions 60 formed in each of metal plates 30, 40 have the same function and structure as each other. Therefore, the same reference mark is given to each of the structural portions. Then, the same reference marks are also given to through-holes 52, recesses 51, 61, and the like formed in each of structural portions 50, 60. Furthermore, the detailed description of the following structural portions 50, 60 may also be described with only any one of metal plate 30 and metal plate 40 so as to avoid unnecessary duplication.
Next, the configuration of structural portion 50 will be described with reference to
As shown in
As a method for forming through-hole 52, for example, a method for forming through-hole 52 by irradiating metal plates 30, 40 with a laser beam can be exemplified. Hereinafter, the forming method is referred to as a laser method. Through-hole 52 having a small hole diameter can be easily formed by the laser method. Furthermore, recess 51 may be formed by the laser method. By using the laser method, recess 51 having a smaller opening diameter than a recess formed by another method can be easily formed.
Then, as shown in
Furthermore, as shown in
As shown in
It should be noted that in
It should be noted that a rough surface having fine unevenness may be formed on the inner surface of through-hole 52. An anchor effect or the like occurs between through-hole 52 and resin case 20 due to the above-described rough surface. Therefore, through-hole 52 comes into close contact with resin case 20 more firmly. A laser method can be used for forming through-hole 52 also from the viewpoint of the above-described anchor effect. In addition, the above-described rough surface may also be formed on the inner surface of recess 51 similarly to through-hole 52.
Through-hole 52 is preferably formed by the irradiation of second surface 30B with a laser beam. The above-described irradiation method allows the heat generated when a laser beam is applied to be suppressed from influencing a surface constituting a part of first surface 30 A in contact portion 33. This will be described in detail below.
When through-hole 52 or recess 51 is formed by the laser method, the portion irradiated with a laser beam reaches a high temperature due to heat generation. The heat generated in this case is transferred to a region other than the irradiated part in metal plate 30 by heat conduction. Therefore, the above-described region also reaches a high temperature.
In switch case 101, a laser beam is applied on second surface 30B. In other words, a laser beam is applied to a surface opposite to a surface serving as a contact point in electrical contact with movable member 22 (a part of first surface 30 A). When the heat generated by the laser method diffuses by heat conduction, a region affected by the heat of a laser beam at first surface 30A is smaller than a region reaching a high temperature due to heat conduction at second surface 30B which is irradiated with a laser beam, that is, a region affected by the heat of a laser beam at second surface 30B. That is, the influence of heat at first surface 30A is smaller than the influence of heat at second surface 30B. Therefore, irradiating second surface 30B with a laser beam allows a part of first surface 30A in contact portion 33 to be protected against the heat influence of the laser beam. Thus, protecting a part of first surface 30A allows the deformation of contact portion 33 or the elimination of antioxidant formed on a part of a surface of first surface 30A by heat to be suppressed.
Furthermore, setting the surface to be irradiated with a laser beam to second surface 30B allows recess 51 and through-hole 52 to be formed in one manufacturing process. Therefore, the manufacturing process or the manufacturing equipment can be simplified. In addition, structural portion 60 to be described below can also be formed at the same time.
As described above, switch case 101 where structural portion 50 is formed allows resin case 20 to be filled in through-hole 52 as shown in
It should be noted that in structural portion 50, recess 51 and through-hole 52 are arranged side by side in a straight line. However, the arrangement of recess 51 and through-hole 52 is not limited. For example, recess 51 and through-hole 52 may be arranged side by side along a curved line.
It should be noted that recess 51 is not always necessary. Structural portion 50 may include only a plurality of through-holes 52, for example. Not forming recess 51 allows a reduction in the cost for forming recess 51, suppression of a reduction in strength of metal plates 30, 40, and suppression of the influence of the laser method.
It should be noted that although structural portion 50 formed in metal plate 30 is mainly described in the above, the same applies to structural portion 50 formed in metal plate 40.
Next, structural portion 60 will be described.
As shown in
It should be noted that as shown in
The method for forming recess 61 includes the laser method in the same manner as recess 51. Recess 61 having a small opening dimension can be easily formed by the laser method. Then, the laser method allows recesses 51, 61 and through-hole 52 to be simultaneously formed in one manufacturing process. Therefore, the manufacturing process or the manufacturing equipment can be simplified.
In the plurality of recesses 61 shown in
In addition, the plurality of recesses 61 only have to be arranged in such a manner as to surround exposed portion 40C. Therefore, for example, a plurality of recesses 61 may be arranged in such a manner as to constitute a plurality of concentric circles having different radii each of which is centered around the central part of exposed portion 40C, and the plurality of concentric circles may surround exposed portion 40C.
As described above, in structural portion 60, recess 61 can come into close contact with resin case 20 more firmly due to the anchor effect or the like around exposed portion 40C. Therefore, in switch case 101, the infiltration of water or flux from pin hole 20C into housing portion 21 can be suppressed.
It should be noted that although structural portion 60 formed in metal plate 40 is mainly described in the above, the same applies to structural portion 60 formed in metal plate 30.
In the following, switch 100 will be described in detail.
As shown in
The operation of switch 100 will be described.
First, the central part of movable member 22 is pressed via pressing body 23 by pushing pressing body 23 downward via protective sheet 24. Then, movable member 22 is inverted by the press describes above. The lower surface of movable member 22 comes into contact with contact portion 43, and this yields conduction state between terminal portion 31 and terminal portion 41.
Then, when the pressing force is released, movable member 22 is restored to the original dome shape projecting upward by its own restoring force. Then, switch 100 returns to the OFF state in
As described above, switch case 101 and switch 100 can suppress water or flux from infiltrating into housing portion 21 by the improvement of the contact property between resin case 20 and metal plate 30 or the contact property between resin case 20 and metal plate 40.
It should be noted that the technical idea of the present disclosure is not limited to switches. For example, the technical idea can be applied to an electronic component such as an encoder where a resin case is formed in a metal plate by insert molding, and the electronic component including a contact portion exposed from inside the housing portion of the resin case, and a terminal portion exposed outside the resin case.
The switch case and the switch according to the present disclosure suppress the infiltration of water or flux into the switch case with improved contact property between the resin case and the metal plate. The switch case of the present disclosure is useful for an electronic component. Then, the electronic component is useful for an electronic apparatus.
Number | Date | Country | Kind |
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2015-038458 | Feb 2015 | JP | national |
This application is a Continuation of U.S. application Ser. No. 15/548,228 filed Aug. 2, 2017, which is the U.S. National Stage entry of International Application No. PCT/JP2016/000916 filed Feb. 22, 2016, which claims the benefit of Japanese Application No. 2015-038458 filed Feb. 27, 2015, the entire contents of each are hereby incorporated by reference.
Number | Name | Date | Kind |
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20120145526 | Masuda | Jun 2012 | A1 |
20140311882 | Terashita et al. | Oct 2014 | A1 |
20180019077 | Sera | Jan 2018 | A1 |
Number | Date | Country |
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2011-060627 | Mar 2011 | JP |
Entry |
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International Search Report of PCT Application No. PCT/JP2016/000916 dated May 17, 2016. |
Notice of Allowance issued in related U.S. Appl. No. 15/548,228 dated May 10, 2018. |
Non-Final Office Action issued in related U.S. Appl. No. 15/548,228 dated Feb. 1, 2018. |
Number | Date | Country | |
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20180350534 A1 | Dec 2018 | US |
Number | Date | Country | |
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Parent | 15548228 | US | |
Child | 16055925 | US |