This disclosure is directed to switch assemblies, and more particularly is directed to floating switch assemblies and methods for making the same.
Users can provide inputs to electronic devices (e.g., portable media players and cellular telephones) using many different approaches. Some known input components are conventional switch assemblies, which may include a stack up having a switch (e.g., a dome switch). As used herein, the term “stack up” is intended to refer to the layered components that form a switch assembly. Depending on design, a switch assembly stack up may contain several components. A conventional stack up of a switch assembly includes a dome switch having two leads that are soldered to a circuit board, and the circuit board is attached to a bracket. When the switch is pressed, an inner conductive surface of the switch contacts a contact pad on the circuit board to complete a circuit. The pressing of the switch can provide a tactile ‘click’ that enhances the user's interaction with the switch. In some cases, a cosmetic piece may be placed over the switch to form a button. In response to the user pressing the cosmetic piece, the switch is in turn depressed and contacts the contact pad thereby generating an input.
Conventional switch assemblies can suffer from a number of drawbacks that affect performance, assembly, and incorporation into an electronic device. These drawbacks can stem from variations in the stack up of the switch assembly. In particular, the stack up is susceptible to solder height variance, which can result in various height differences between the dome and the circuit board. In addition, height differences can also be realized in the circuit board/bracket interface (e.g., the thickness of the circuit board may vary). If the stack up height exceeds predetermined tolerances, then the switch assembly may not be able to fit within an electronic device it is designed to be used with, or the switch assembly may not function in its intended manner if it does not fit properly.
Accordingly, there is a need for improved switch assemblies that mitigate stack up variations.
Switch assemblies that mitigate stack up variations and methods of making the same are provided. The stack up variations are mitigated by embodiments that use a floating switch design. The floating switch design may eliminate height variations in the stack up by directly mounting an activation assembly to a support bracket. This ensures that the stack up height of the activation assembly and support bracket remain fixed, independent of a flexible printed circuit board (PCB) that may also be secured to the activation assembly. This way, regardless of the thickness of the flexible PCB and any height variations in solder used to secure the flexible PCB to the activation assembly, the stack up height of the activation assembly and support bracket remains fixed. Thus, the flexible PCB floats relative to the activation assembly, and any variations in solder height will vary the height of the flexible PCB relative to the activation assembly, but have no effect on the overall height of the switch stack up.
According to a particular embodiment, a floating switch assembly includes a bracket, an activation assembly, and a flexible printed circuit board. The activation assembly is mounted on the bracket. The flexible printed circuit board is coupled to the activation assembly, and is operative to move, or float, relative to the activation assembly.
According to another particular embodiment a floating switch assembly includes a bracket, an activation assembly, a flexible printed circuit board, and a support member. The activation is fixed to the bracket. The flexible printed circuit board is coupled to the activation assembly, and is operative to float relative to the activation assembly. The support member is operative to support the flexible printed circuit board without interfering with the flotation of the flexible printed circuit board.
According to yet another embodiment, a method of forming a floating switch assembly having a bracket, an activation assembly, and a flexible printed circuit board is disclosed. The method includes placing the activation assembly on a surface of the bracket and coupling the flexible printed circuit board to the activation assembly such that the flexible printed circuit board is operative to float relative to the activation assembly.
The above and other features of the present invention, its nature and various advantages will be more apparent upon consideration of the following detailed description, taken in conjunction with the accompanying drawings in which:
Floating switch assemblies and methods for making the same are described below with reference to
Floating switch assembly 100 may include activation assembly 110, bracket 120, flexible printed circuit board (PCB) 130, and support members 140. Activation assembly 110 may further include terminals 111 and actuator 112. Flexible PCB 130 may also include cutout 131. Activation assembly 110 is mounted directly to bracket 120 using any suitable approach (e.g., using an adhesive). Flexible PCB 130 is mounted directly to activation assembly 110 via terminals 111 and may be mounted to bracket 120 via support members 140.
Activation assembly 110 may be designed to house a suitable switch (e.g., actuator 112), and may be constructed from any suitable material (e.g., plastic). Terminals 111 may be integrated into activation assembly 110 and may protrude from the box-like region of activation assembly 110. Terminals 111 may be made from any suitable conductive material such as, for example, metal. Although activation assembly 110 is depicted as box shaped, it is understood that activation assembly 110 may have any suitable shape. Activation assembly 110 is operative to register switch events when a user presses down on actuator 112 in the direction of arrow A. Activation assembly 110 can convey information through terminals 111 via an electrical signal when a switch event occurs.
Bracket 120 serves as an anchor for activation assembly 110. For example, bracket 120 can support activation assembly 110 when the user presses on actuator 112. In this manner, bracket 120 may ensure that activation assembly 110 does not move or recede when force is applied to it. Bracket 120 may also provide support for other portions of floating switch assembly 100 (e.g., support members 140).
Flexible PCB 130 may include traces for relaying switch events to another component of an electronic device. For example, when switch events occur within activation assembly 110, flexible PCB 130 may relay the switch events to a processing unit (not shown) of the electronic device. Flexible PCB 130 may also include other components (not shown) of the electronic device. Flexible PCB 130 may fit around some or all of activation assembly 110. In order to properly fit around activation assembly 110, flexible PCB 130 may include cutout 131. Although cutout 131 is shown as a rectangular cutout, cutout 131 can be any shape needed to accommodate activation assembly 110. For example, cutout 131 may have a shape similar to activation assembly 110. More generally, one skilled in the art will appreciate that cutout 131 may have any suitable shape and dimensions to accommodate a floating switch design. Because flexible PCB 130 fits around activation assembly 110, it does not contribute to the overall stack up height of floating switch assembly 100.
Support members 140 may be positioned adjacent to activation assembly 110 and can couple flexible PCB 130 to bracket 120. Support members 140 may be constructed from a compliant material (e.g., foam, rubber, and/or plastic) that is operative to support flexible PCB 130 without hindering movement of flexible PCB 130.
The coupling interaction of activation assembly 110, bracket 120, and flexible PCB 130 enables PCB 130 to move, or float, relative to activation assembly 110. As used herein, the term “float” is intended to mean that an object is able to undergo fluid movement relative to another object. The fluid movement may include translational movement, rotational movement, or a combination thereof.
The floating aspect of switch assembly 100 is achieved, in part, based on the design of flexible PCB 130 and how it is coupled to bracket 120 and terminals 111. As shown in
Terminals 111 may be coupled to flexible PCB 130 using any suitable approach, for example, via solder. Flexible PCB 130 may be coupled to terminals 111 such that the ability of flexible PCB 130 to float relative to activation assembly 110 is not hindered. In some embodiments, terminals 111 may be operative to flex or rotate in order to allow for increased movement of flexible PCB 130 relative to activation assembly 110. Flexing of terminals 111 may be about one axis of switch assembly 111 (e.g., about an axis out of the page of
By incorporating a floating switch design, floating switch assembly 100 can mitigate stack up variations. Floating switch assembly 100 may eliminate height variations in its stack up because the stack up height of activation assembly 110 and bracket 120 remain fixed, independent of flexible PCB 130. This way, regardless of the thickness of flexible PCB 130 and any height variations in the coupling between flexible PCB 130 and terminals 111, the stack up height of activation assembly 110 and bracket 120 remains fixed. Thus, flexible PCB 130 floats relative to activation assembly 110, and any variations (e.g., in solder height) will vary the height of flexible PCB 130 relative to activation assembly 110, but have no effect on the overall height of floating switch assembly 100. As shown in
In contrast, conventional switch assemblies are formed by soldering an activation assembly on top of a circuit board. The circuit board is then fixed to a bracket. In this manner, conventional switch assemblies include a circuit board in their stack up and add height to their stack up as a result. Additionally, any variations in the uniformity of the circuit board or in the coupling of the activation assembly and the circuit board affect the orientation of the activation assembly. As a result, undesirable variations may cause conventional switch assemblies to function improperly.
Structural member 213 may be fixed to bracket 220 using adhesive 214. Structural element 213 may be constructed from a rigid material and can provide structural support to other elements of activation assembly 210. For example, structural element 213 may provide structural support to switch 212, terminals 211, or any other portion of activation assembly 210.
Terminals 211 may be coupled to flexible PCB 230 using coupling joint 216. Coupling joint 216 may electrically couple terminals 211 to flexible printed circuit board 230 using any suitable conductive material (e.g., solder). Coupling joint 216 may be constructed such that flexible printed circuit board 230 is operative to float relative to activation assembly 210.
Switch 212, depicted as a dome-shaped switch in
As shown in
Returning to
Support members 240 may be positioned adjacent to coupling joint 216 and can support flexible PCB 230 to prevent unnecessary strain on flexible printed circuit board 230, terminals 211, and/or coupling joint 216. Support members 240 may further include compliant members 241 and support member adhesives 242. Compliant members 241 may be fixed to bracket 220 using support member adhesives 242. Compliant members 241 may be constructed from a compliant material (e.g., foam, rubber, or plastic) that is operative to support flexible printed circuit board 230 without compromising its ability to move relative to activation assembly 210.
Referring to
Activation assembly 310 may be fixed to bracket 320 using any suitable approach (e.g., using adhesive 314). In some embodiments, activation assembly 310 may include alignment posts 317 to engage bracket 320. Alignment posts 317 may secure activation assembly 310 to bracket 320 and may prevent activation assembly 310 from moving relative to bracket 320. Alignment posts 317 may be any suitable shape, including, but not limited to, cylindrical, spherical, ellipsoidal, hexahedral, tetrahedral, or combinations thereof. Bracket 320 may include a corresponding feature configured to receive alignment posts 317. In some embodiments, alignment posts 317 may include at least one feature (not shown) that secures structural member 313 to bracket 320 (e.g., a snap or a hook).
Electronic device 300 may also include a cosmetic actuator (e.g., actuator 350) positioned over activation assembly 310. Actuator 350 is secured within housing 360 and forms an outer surface of electronic device 300. Actuator 350 may be made from any suitable material, including, but not limited to metal, rubber, plastic, or combinations thereof. Actuator 350 may provide an aesthetically pleasing outer surface of electronic device 300, and may also protect inner components of electronic device 300 from shock or other physical damage.
Shim 370 may be included between actuator 350 and activation assembly 310 to support actuator 350, adjust for a better fit between actuator 350 and activation assembly 310, and/or provide a level surface which actuator 350 may be seated on. Shim 370 may be constructed from any suitable material. For example, shim 370 may be constructed from metal, plastic, or any other suitable material.
Electronic device 300 may include bracket pin 380 and bracket screw 390 which secure bracket 320 to housing 360. Bracket pin 380 may be operative to be inserted into housing 360. When inserted in housing 360, bracket pin 380 may provide a hinge to which one end of bracket 320 may be attached. The other end of bracket 320 may be secured via bracket screw 390. Bracket screw 390 may be threaded into housing 360 and tightened to hold bracket 320 in place against housing 360.
As shown in
Switch 512 may be operative to deform when actuated such that the inner surface of switch 512 contacts contact pad 515 and provides a conductive path between terminals 511. The pressing of switch 512 may also provide a tactile ‘click’ that enhances a user's interaction with switch 512. When switch 512 is depressed, air from under switch 512 may travel through vent hole 518. Vent hole 518 may be any suitable size. In some cases, vent hole 518 may have a volume smaller than the internal volume of switch 512 while in other cases vent hole 518 may have a volume substantially the same as the internal volume of switch 512.
In some embodiments, vent hole 518 may be in fluid communication with an internal venting volume (not shown). In other embodiments, additional layers may be provided to further aid in forming the internal venting volume. For example, pockets may be formed with at least one film in fluid communication with the internal volume of switch 512.
As used herein, the term “electronic device” can include, but is not limited to, music players, video players, still image players, game players, other media players, music recorders, video recorders, cameras, other media recorders, radios, medical equipment, calculators, cellular telephones, other wireless communication devices, personal digital assistants, programmable remote controls, pagers, laptop computers, printers, or combinations thereof.
The previously described embodiments are presented for purposes of illustration and not of limitation. It is understood that one or more features of an embodiment can be combined with one or more features of another embodiment to provide systems and/or methods without deviating from the spirit and scope of the invention. It will also be understood that various directional and orientational terms are used herein only for convenience, and that no fixed or absolute directional or orientational limitations are intended by the use of these words. For example, the devices of this invention can have any desired orientation. If reoriented, different directional or orientational terms may need to be used in their description, but that will not alter their fundamental nature as within the scope and spirit of this invention. Those skilled in the art will appreciate that the invention can be practiced by other than the described embodiments, which are presented for purposes of illustration rather than of limitation, and the invention is limited only by the claims which follow.
Number | Date | Country | |
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Parent | 13589236 | Aug 2012 | US |
Child | 14717005 | US |