Patent Publication Number: US-2016240332-A1

Title: Switch apparatus and manufacturing method thereof

Description:
RELATED APPLICATIONS 
     This application claims priority to International Application No. 2015021600399310, filed on Feb. 16, 2015, and entitled “SWITCH APPARATUS AND MANUFACTURING METHOD THEREOF.” This application claims the benefit of the above-identified application, and the disclosure of the above-identified application is hereby incorporated by reference in its entirety as if set forth herein in full. 
     BACKGROUND 
     A switch may be used to open or close a portion of a circuit is rigidly fixed onto a substrate. For example, a typical mobile device may include a few switches located laterally on the device for adjusting volume, switching on/off the device, and the like. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  illustrate a block diagram of a switch according to one embodiment of the subject matter described herein; 
         FIG. 2  illustrates a perspective view of a switch according to one embodiment of the subject matter described herein; 
         FIG. 3  illustrates a exploded view of the switch as illustrated in  FIG. 2  according to one embodiment of the subject matter described herein; 
         FIG. 4  illustrates a sectional view of the switch as illustrated in  FIG. 2  according to one embodiment of the subject matter described herein; 
         FIG. 5  illustrates a side view of the switch as illustrated in  FIG. 2  according to one embodiment of the subject matter described herein; 
         FIG. 6  illustrates a top view of the switch as illustrated in  FIG. 2  which is connected to a substrate of an electronic device according to one embodiment of the subject matter described herein; and 
         FIG. 7  illustrates a flowchart of a method of manufacturing the switch in accordance with embodiments of the subject matter described herein. 
     
    
    
     DETAILED DESCRIPTION 
     The subject matter described herein will now be discussed with reference to several example embodiments. It should be understood these embodiments are discussed only for the purpose of enabling those skilled persons in the art to better understand and thus implement the subject matter described herein, rather than suggesting any limitations on the scope of the subject matter. 
     As used herein, the term “includes” and its variants are to be read as opened terms that mean “includes, but is not limited to.” The term “or” is to be read as “and/or” unless the context clearly indicates otherwise. The term “based on” is to be read as “based at least in part on.” The term “one embodiment” and “an embodiment” are to be read as “at least one embodiment.” The term “another embodiment” is to be read as “at least one other embodiment.” Other definitions, explicit and implicit, may be included below. 
     A switch may be implemented as a component protruding from the housing of the device. In some instances, a force that is much larger than the minimum actuation force may be applied to the switch, for example, when the device is dropped onto the floor. A user typically applies a normal force to the switch of a mobile device at or below 5N. The impact on the switch as the device drops on the floor, however, can reach a level of 80N. Such an excessive force would probably damage the substrate or detach the switch from the substrate. 
       FIG. 1  illustrates a block diagram of a switch  100  according to one embodiment of the subject matter described herein. It is to be understood that the switch  100  is described only for the purpose of illustration, without suggesting any limitations as to the scope of the subject matter described herein. Different embodiments with different structures can realize the purpose and concept of the subject matter described herein. 
     As shown, the switch  100  includes a switch assembly  110  adapted to receive a force in a certain direction. The force applied on the switch assembly  110  is referred to as the “first force,” and the direction of the first force is referred to as the “first direction”. The first force may be applied by a user operating the switch  100  and/or by another actuator operated in response to a certain command. 
     The switch  100  further includes a protective member  120  arranged on a substrate  200  and adapted to receive the switch assembly  110 . The protective member  120 , among other things, includes a spring portion  121  which applies a force to the switch assembly  110  in a direction that is essentially opposite to the first direction. The force applied by the spring portion  121  is referred to as the “second force,” and the direction of the second force is referred to as the “second direction”. 
     In accordance with embodiments of the subject matter described herein, the switch assembly  110  is not rigidly fixed to the substrate  200  of the hosting device. Instead, if the first force exceeds a predefined threshold value, the switch assembly  110  can be moved relative to the substrate  200 . 
     In this configuration, the second force is pre-loaded in the second direction. As a result, in the case that the first force is smaller than the second force, the switch assembly  110  will not be moved. However, if the first force is larger than the predefined threshold value, the spring portion  121  will be deformed which will in turn cause the switch assembly  110  to be moved in the first direction. As the first force increases, the spring portion  121  is further deformed and the switch assembly  110  is further moved. The deformation of the spring portion  121  absorbs excessive energy by the first force and thus avoids the direct impact to the substrate  200 . In addition, the resulting shear stress on the connectors, such as pins that may couple the switch  100  onto the substrate  200 , can be significantly reduced. 
     With reference to  FIG. 2 , a perspective view of an implementation of the switch  100  according to one embodiment of the subject matter described herein is shown. In this implementation, the protective member  120  of the switch  100  receives a button housing  140 . The switch  100  comprises a pressing member  131  that is constrained by the button housing  140 . For example, the pressing member  131  may be contained in the button housing  140  and allowed to be moved relative to the button housing  140  in response to a force applied on the pressing member  131 . 
     As shown, the protective member  120  further includes a fixing portion  122  that couples or connects the protective member  120  onto a substrate (not shown). In one embodiment, the connection between the protective member  120  and the substrate may be rigid. For example, soldering or interference fit may be used to couple the protective member  120  to the substrate. As a result, the switch  100  as a whole is also connected to the substrate as shown in  FIG. 2  when there is no force exerted on the switch  100 . Of course, the flexible coupling is possible as well, depending on the specific application or requirement, for example. 
       FIG. 3  shows an exploded view of the components of the switch  100  as illustrated in the embodiment of  FIG. 2 . In the embodiment as shown in  FIG. 3 , in addition to components as shown in  FIG. 2 , the switch  100  further includes a front housing  141 , a film member  133 , a resisting member  132 , a pair of contacts  150  and a rear housing  142 . 
     Each of the front housing  141  and the rear housing  142  is a part of the button housing  140 , which constrains the movement of the pressing member  131  as discussed above. Each of the pressing member  131 , the film member  133 , and the resisting member  132  is a part of the button assembly  130  capable of being operated by an end user. In one embodiment, the film member  133  is a wear resistant part used to reduce impact directly onto the resisting member  132 . The resisting member  132  may be used to electrically connect the pair of the contacts  150  coupled to the substrate responsive to the resisting member  132  being deformed to a certain extent, and the deformed resisting member  132  in turn switches on a circuit on the substrate. The front housing  141 , the pressing member  131 , the film member  133 , the resisting member  132 , the pair of contacts  150  and the rear housing  142  forms a switch assembly  110  allowed to be moved relative to the protective member  120  in response to the first force exceeding the predefined threshold value. The functionalities of these components will be detailed below. 
     As mentioned above, in one embodiment, the film member  133  can be made of wear-resistant materials in order to protect the resisting member  132  from dust and dirt. In addition, the film member  133  may be used to reduce impact directly onto the resisting member  132  and thus prolong the life span of the switch. The switch  100  may operate with or without the film member  133 . 
     The contacts  150  are used to control the status of the switch  100 . Particularly, the switch  100  will be closed when the pair of contacts  150  is electrically connected and will be opened when the pair of contacts  150  is electrically disconnected. Although only a single pair of switches is shown in  FIG. 3 , other implementations are possible that include additional or different types of switches. There can be any suitable number of pairs of contacts in the switch  100 . 
     In one embodiment, the contacts  150  can be made of a conductive material, such as copper, which has an excellent conductivity and toughness. Additionally or alternatively, the protective member  120  may be made of metal material such as copper, which is tough. The button housing  140  including the front housing  141  and the rear housing  142  and the pressing member  131  may be made of insulating materials, for example. 
     In another embodiment, the contacts  150  and the resisting member  132  can be plated with gold, which provides great signal transmission properties, mating durability, and excellent oxidation resistance against polluted environments. Additionally, the contacts  150  and the resisting member  132  can also be plated with nickel beneath the gold layer acting as a diffusion barrier. Alternatively, silver can be plated for applications where low intermodulation is required, and chrome can be plated for connectors used in harsh environment such as in military applications. 
     The above examples are described only for the purpose of illustration, without suggesting any limitations as to the scope of the subject matter described herein. Any additional or alternative materials can be used to make the components of the switch. 
     As discussed above, the protective member  120  can prevent the damage caused by excessive force. Without the protective member  120 , the button housing  140  cannot be moved relative to the substrate. Thus an excessive force exerted on the pressing member  131  will be mostly transmitted to the substrate and the resulting shear stress on connectors such as pins of the switch may be destructive when the force is too large, for example larger than 80N, as described above. By use of the protective member  120  which allows relative movement of the switch assembly  110  with respect to the substrate, the potential damage can be eliminated. 
       FIGS. 4 and 5  illustrate a sectional view and a side view of the switch  100  as shown in  FIGS. 2 and 3 , respectively.  FIG. 6  illustrates a top view of the switch  100  according to the embodiment of the subject matter described herein as shown in  FIGS. 2 and 3  being connected to a substrate of an electronic device. Although the switches as shown in  FIGS. 4 to 6  are of the same size and shape, it is to be understood that this particular example of the switch can be made and shaped differently. 
     With reference to  FIGS. 4 and 5 , as shown, the switch assembly  110  is received and constrained in the protective member  120 . In one embodiment, the protective member  120  may be shaped to have a front panel  125  enabling the pressing member  131  protruding out of the protective member  120 . In addition to the fixing portion  122 , the protective member  120  may further include two opposite side walls  123  and a top wall  124 . Furthermore, in the shown embodiment, the spring portion  121  of the protective member  120  is implemented as two curved spring pieces  121  that are located opposite to the front panel  125 . The protective member  120  defined by the front panel  125 , the spring portions  121 , the fixing portion  122 , the side walls  123  and the top wall  124  are together used to define a container in which the switch assembly  110  can be fitted. 
     In one embodiment, a front positioning portion  143  may be provided on the front housing  141 . In one embodiment, the front positioning portion  143  protrudes out of the front panel  125  through an aperture formed on the front panel  125  of the protective member  120 . In this way, the front positioning portion  143  allows a close fit between the front housing  141  and the front panel  125  of the protective member  120 . 
     Although two front positioning portions  143  are shown in  FIGS. 2 to 4 , this is only for the purpose of illustration without suggesting any limitations as to the scope of the subject matter described herein. The front housing  141  may include any suitable number of the front positioning members. Any suitable number may be used to achieve a close fit between the front housing  141  and the front panel  125  of the protective member  120  when the switch assembly  110  is mounted within the protective member  120 . Likewise, the shape factor of the front positioning portions  143  is not limited to the example shown in  FIGS. 3 and 4 . 
     Additionally or alternatively, in one embodiment as shown in  FIGS. 3 and 5 , two lateral positioning portions  144  are provided on the front housing  141 . Each of the lateral positioning portions  144  may protrude out of a respective aperture formed on each of the side walls  123 . The apertures may allow the lateral positioning portions  144  to be moved in a certain direction only. To this end, in one embodiment, the apertures on the side walls  123  may be of an elongated shape. For example, in the example embodiment shown in  FIG. 5 , the long side of the aperture on the side wall  123  is longer than that of the lateral positioning portion  144 , which allows a horizontal movement of the switch assembly  110  with respect to the protective member  120  responsive to a force exceeding the predefined threshold value. The movement will be described in detail in the following paragraphs. Movement in any other suitable direction is possible as well. 
     Although two lateral positioning portions  144  are provided for the particular example as shown in  FIGS. 3 and 5 , this is only for the purpose of illustration without suggesting any limitations as to the scope of the subject matter described herein. The front housing  141  may include any suitable number of the lateral positioning portions to achieve a guided movement along the first and second directions when the switch assembly  110  is mounted within the protective member  120 . Likewise, the shape factor of the lateral positioning portions  144  is not limited to the example shown in  FIGS. 3 and 5 . 
     In one embodiment, the spring portions  121  may be already compressed against the rear housing  142  when the switch assembly  110  is mounted in the protective member  120 . In other words, at this point, the second force has been applied by the compressed spring portions  121  to the rear housing  142 , or the entire switch assembly  110 . Such pre-loaded second force pushes the switch assembly as a whole against the front panel  125  of the protective member  120 . As a result, the front housing  141  and the rear housing  142  are closely positioned within the protective member  120 . 
     The particular embodiment shown in  FIG. 4  includes flat surfaces on the front housing  141  and the rear housing  142  in contact with each other so that the front housing  141  and the rear housing  142  can be closely positioned. Additional fittings may be provided for fixing the front housing  141  to the rear housing  142 . The subject matter described herein is not limited to the form of these surfaces beyond that fact that they allow the front housing  141  to be securely matched with the rear housing  142 . 
     Although the button housing  140  of the particular example shown in  FIG. 4  includes both the front housing  141  and the rear housing  142 , in other examples, the button housing  140  may include any suitable number of components. The component(s) can restrict the movement of the button assembly  130  in the first and second directions. For example, the button housing may be formed integrally with only one component or may be formed with more than two components in some other implementations. 
     In one embodiment, as shown in  FIG. 4 , a chamber may be formed within the button housing  140  for containing the button assembly  130 , namely, the pressing member  131 , the resisting member  132 , and the film member  133 . 
     In one embodiment, the pressing member  131  can be made in the form of a plunger to be pressed by the first force denoted as “F 1 ” in  FIG. 4 . The pressing member  131  may be any shape or size such that a portion of it protrudes out of an opening on the front housing  141  for being pressed while the remainder of it can be confined by the front housing  141  so that the pressing member  131  can be held by the front housing  141 . 
     In one embodiment, the resisting member  132  can be made in the form of a dome, which can be elastically deformed in response to a force larger than a certain value. In this example embodiment, the resisting member  132  can be made of an electrically conductive material such as copper. When the first force F 1  is large enough to deform the resisting member  132 , the resisting member  132  may collapse onto the rear housing  142  after moving for a threshold distance in the first direction. As a result, the contacts  150  received in the rear housing  142  are electrically connected with one another. 
     In one embodiment, the resisting member  132  may be resilient or elastically deformable such that the resisting member  132  is able to undergo numerous times of deformation process back and forth. The resisting member  132  may be designed to provide a reactive force responsive to the first force. Specifically, the resisting member  132  may provide a force (referred to as “third force”) in the second direction, which is essentially opposite to the first direction as described above, in response to the pair of contacts  150  being electrically connected. When the switch  100  is designed to be used in a mobile phone, by way of example only, the operational force applied by the end user is generally below 10N. Accordingly, the resisting member  132  may be designed to provide the third force of about 3N, for example. In this event, the total force needed to make the resisting member  132  electrically connect the pair of contacts  150  is equal to the third force, no matter if the resisting member  132  is pre-compressed against the front panel  125  or not. 
     The user does not have to apply the pressing force exactly in the first direction. Instead, the pressing force may be applied with a certain angle with respect to the first direction. In this event, the first force Fl may be the component of the pressing force along the first direction. In one embodiment, the pressing member  131  may be shaped to be confined in the button housing  140  along the direction perpendicular to the first direction, in order to prevent the pressing member  131  from being moved by the component of the pressing force along the perpendicular direction. 
     In one embodiment, the spring portion  121  may be designed such that the second force provided by the spring portion  121  is larger than the third force. In this way, it is possible to ensure that the first force F 1  will deform the resisting member  132  firstly if F 1  is larger than the third force. The spring portion  121 , however, will not be deformed as long as the first force F 1  is smaller than the second force. That is to say, the spring portion  121  may be designed to be deformed only when the first force F 1  exceeds a certain value, i.e., the predefined threshold value as described above. Therefore, when the first force is in a range large enough to move the pressing member but not too large to deform the spring portion  121 , the switch  100  may be operated normally. Because the first force within this range is not excessive, it may not produce any destructive effect to the switch itself or to the surface to which the switch is fixed. On the other hand, when the first force F 1  exceeds the predefined threshold value, the entire switch assembly  110  will be moved in the first direction and thus deform the spring portion  121  to some extent. 
     As discussed above, in some embodiments, the second force is a predefined and pre-loaded force which has been already applied onto the button housing  140  in the absence of the first force. The pre-loaded second force is advantageous for the reason that a normal operational force applied by the user is usually smaller than the pre-loaded second force. As a result, an excellent tactility comparable to a conventional switch without such a pre-loaded protective mechanism can be achieved. If a pre-loaded force is absent, however, the user pressing the switch may feel that the button is too loose as the button housing  140  and the pressing member  131  may move in the first direction altogether. In addition, the force applied in the first direction needs to gradually increase if the button housing  140  is to be moved for a longer distance in the first direction. During this process, the spring portion  121  can absorb and store energy as it is deformed, and thus the stress will not be significantly increased between the switch and the substrate as the first force F 1  increases. As such, the excessive force applied on the pressing member  131  in the first direction will not break the substrate or detach the switch from the substrate. 
     In one embodiment, the predefined threshold value may be defined as the sum of the second force and the third force. For example, for side buttons of a mobile phone, the second force provided by the pre-compressed spring portion may be around 20N, which is significantly larger than the third force, e.g., 3N. Therefore, the first force will not move the button housing  140  relative to the protective member  120  if it is smaller than 23N. If the first force exceeds 23N, it will move the button housing  140  more or less in the first direction, depending on how large the first force is. If the first force is removed from the pressing member  131 , the spring portion  121  and the resisting member  132  will respectively return the button housing  140  and pressing member  131  back to the stage as shown in  FIG. 3 . 
     As shown in  FIG. 5 , in one embodiment, an elastic portion  151  may be provided for each of the contacts  150 . The elastic portion  151  is adapted to be elastically deformed as the switch assembly  110  moves relative to the substrate (or the fixing portion  122 ) in the first direction. The elastic portion  151  may be used to further absorb the energy from the first force, thereby preventing the excessive energy from being transmitted to the substrate. 
     In some other example embodiments, each of the contacts  150  may be electrically coupled to the substrate in a flexible connection. In this particular configuration, the contacts  150  may be constructed by electric wires which provide no rigidity. As the contacts  150  are flexible, they can be arbitrarily shaped in accordance with any movement of the switch assembly  110 , meaning that the first force may not be transmitted to the substrate via the contacts  150 . 
     By means of pre-loaded force provided by the spring portion  121 , the switch  100  may be protected when the operational force is relatively large. A large portion of the energy from an impact to the switch  100  can be absorbed instead of being directly transmitted to the substrate, thereby avoiding possible fracture occurring between the switch  100  and the substrate. 
     As shown in  FIG. 6 , the switch  100  according to the subject matter described herein may be attached to a substrate  200 . For example, the fixing portions  122  may be fixed to the substrate  200  through fixing holes  220  by way of soldering or interference fit, and the ends of the contacts  150  may be fixed to the substrate  200  through contact holes  210  by way of soldering. 
     It is to be understood that “top”, “bottom”, “front”, “rear”, “side”, “lateral” and the like are only used to describe the relationship between the components in the figures, instead of limiting their orientation or positioning. For example, in  FIG. 6 , the switch  100  can be seen as being placed above the substrate  200 , and can also be seen as being placed underneath the substrate  200 . In addition, although the spring portion  121  as shown by  FIGS. 3 to 6  is placed at the rear side of the switch  100 , it can be understood that a spring portion placed aside the switch  100  holding the rear housing  142  may also work. 
     With reference to  FIG. 7 , it illustrates a block diagram of a method  700  of manufacturing the switch  100  in accordance with embodiments of the subject matter described herein. The method  700  is entered at step S 701 , where a switch assembly is provided. The switch assembly is adapted to receive a first force in a first direction can be provided. 
     At step S 702 , a protective member arranged on a substrate and adapted to receive the switch assembly is provided. The protective member comprising a spring portion applying a second force to the switch assembly in a second direction that is opposite to the first direction. The switch assembly can be moved relative to the substrate in response to the first force exceeding a predefined threshold value. 
     In one embodiment, providing the switch assembly at step S 701  comprises providing a button assembly, the button assembly comprising a pressing member adapted to receive the first force, and providing a button housing adapted to receive the button assembly, where the pressing member is adapted to be moved relative to the button housing in the first direction responsive to the first force. 
     Additionally or alternatively, providing the switch assembly at the step S 701  may comprise providing at least one pair of contacts received in the button housing, and providing a resisting member adapted to electrically connect the pair of contacts in response to the pressing member moving in the first direction for a threshold distance. As discussed above, in one embodiment, the resisting member is adapted to provide a third force in the second direction in response to the pair of contacts being electrically connected. Specifically, the resisting member may be adapted to provide the third force that is less than the second force. In one embodiment, the protective member may be integrally made of metal, for example. 
     In one embodiment, the method  700  may comprise a step of providing each of the contacts electrically coupled to the substrate by a flexible connection (not shown). Alternatively or additionally, in one embodiment, the method  700  may comprise steps of electrically coupling the pair of contacts to the substrate and providing an elastic portion on each of the contacts. The elastic portion is adapted to be elastically deformed as the switch assembly moves relative to the substrate in the first direction, each of the contacts being electrically connected to the substrate through the elastic portion. 
     While operations are depicted in a particular order in the above descriptions, this should not be understood as requiring that such operations be performed in the particular order shown or in sequential order, or that all illustrated operations be performed, to achieve desirable results. In certain circumstances, multitasking and parallel processing may be advantageous. Likewise, while several details are contained in the above discussions, these should not be construed as limitations on the scope of the subject matter described herein, but rather as descriptions of features that may be specific to particular embodiments. Certain features that are described in the context of separate embodiments may also be implemented in combination in a single embodiment. On the other hand, various features that are described in the context of a single embodiment may also be implemented in multiple embodiments separately or in any suitable sub-combination. 
     Although the subject matter has been described in language specific to structural features and/or methodological acts, it is to be understood that the subject matter defined in the appended claims is not necessarily limited to the specific features or acts described above. Rather, the specific features and acts described above are disclosed as example forms of implementing the claims.