Patent Publication Number: US-2012039052-A1

Title: Electronic communication device and method

Description:
RELATED APPLICATIONS 
     This application is a continuation-in-part of and claims priority to U.S. patent application Ser. No. 13/055,389, filed May 16, 2011, which application is a national stage application of and claims priority to International Patent Application PCT/US2008/008860, filed Jul. 21, 2008, which application is a continuation-in-part of and claims priority to International Patent Application PCT/US2007/007806, filed Mar. 29, 2007, which application is a continuation-in-part of and claims priority to U.S. patent application Ser. No. 11/396,263, filed Mar. 30, 2006, now U.S. Pat. No. 7,897,888, issued Mar. 1, 2011. 
    
    
     BACKGROUND OF THE INVENTION 
     Conventional key fobs often include a two-piece housing, molded silicone rubber buttons, a printed circuit board (“PCB”), an antenna, and a battery clip coupled to one of the two pieces of the housing. To reduce costs, the pieces of the housing are typically made from black plastic. At least one piece of the housing usually includes one or more apertures for receiving a button. The buttons are usually defined by a single piece of molded silicone rubber that is substantially the same size as the housing. In many cases, the molded rubber piece is positioned inside the two pieces of the housing with the buttons aligned with the apertures in the housing. The molded rubber piece also usually includes a lip around its perimeter that provides a seal between the two pieces of the housing. Carbon pieces can be attached to the undersides of the buttons. Normally, the PCB is positioned beneath the silicon rubber buttons and includes electrical traces. When a button is depressed, the carbon piece on the underside of the button closes the traces on the PCB and activates a desired feature on a vehicle. 
     For a family of conventional key fobs (having different functionalities), an entire family of tooling is typically required to accommodate varying numbers of buttons, patterns, textures, and other styling. Due to the costs of the additional tooling, molding a family of key fobs with different features and styling is usually difficult and expensive. Similar problems arise in other applications, such as for other portable and non-portable electronic communication devices (e.g., mobile phones, GPS devices, audio equipment, and the like). 
     SUMMARY OF THE INVENTION 
     In some embodiments, a key fob is provided, and comprises a spacer layer defining at least one aperture; and a flexible film covering at least a portion of the spacer layer and defining an exterior surface of the key fob, the flexible film including at least one contact surface and a surface adjacent to the at least one contact surface, the at least one contact surface flexing when a force is applied in order to actuate at least one switch. 
     Some embodiments of the present invention provide a key fob comprising a flexible circuit including at least one switch; and a flexible film covering at least a portion of the flexible circuit and defining an exterior surface of the key fob including at least one contact surface, the at least one contact surface flexing when a force is applied in order to actuate the at least one switch. 
     In some embodiments, a method of forming a key fob is provided, and comprises: providing a flexible spacer layer including at least one aperture; providing a flexible film defining an exterior surface of the key fob including at least one contact surface and a surface adjacent to the at least one contact surface, the at least one contact surface flexing when a force is applied in order to actuate at least one switch; and joining the flexible spacer layer and the flexible film. 
     Some embodiments of the present invention provide a key fob, comprising: a flexible film defining an exterior surface of the key fob including at least one contact surface, the at least one contact surface flexing when a force is applied in order to actuate the at least one switch; and encapsulating material defining at least a portion of an interior of the key fob. 
     In some embodiments, a method of forming a key fob is provided, and comprises: providing a flexible film defining an exterior surface of the key fob including at least one contact surface and a surface adjacent to the at least one contact surface, the at least one contact surface flexing when a force is applied in order to actuate at least one switch; and injecting an encapsulating material into a mold to define at least a portion of an interior of the key fob. 
     Some embodiments of the present invention provide a key fob, comprising: a substantially transparent flexible film defining an exterior surface of the key fob including at least one contact surface, the at least one contact surface flexing when a force is applied in order to actuate at least one switch included in the key fob, the substantially transparent flexible film including a printed interior surface. 
     In some embodiments, a key fob is provided, and comprises a flexible film defining an exterior surface of the key fob including at least one contact surface, the at least one contact surface flexing when a force is applied in order to actuate the at least one switch, the flexible film formed to define an upper surface and a side surface of the key fob. 
     Some embodiments of the present invention provide a method of forming a key fob, comprising: providing a substantially transparent flexible film defining an exterior surface of the key fob, the exterior surface including at least one contact surface, the at least one contact surface flexing when a force is applied in order to actuate the at least one switch; and printing on an interior surface of the substantially transparent flexible film. 
     In some embodiments, a key fob is provided, and comprises a switch matte including at least one actuation finger and a flexible film covering at least one portion of the switch matte and defining an exterior surface of the key fob, the flexible film including at least one contact surface and a surface adjacent to the at least one contact surface, the at least one contact surface flexing when a force is applied in order to actuate at least one switch. 
     Some embodiments of the present invention provide a key fob comprising a flexible circuit including at least one switch, a flexible film covering at least a portion of the flexible circuit and defining an exterior surface of the key fob including at least one contact surface, the at least one contact surface flexing when a force is applied in order to actuate the at least one switch, and a switch matte including at least one actuation finger, the at least one actuation finger aligning with the at least one switch and the at least one contact surface. 
     Some embodiments of the present invention provide a method of forming a key fob, comprising: providing a switch matte including at least one actuation finger, providing a flexible film defining an exterior surface of the key fob including at least one contact surface and a surface adjacent to the at least one contact surface, the at least one contact surface flexing when a force is applied in order to actuate at least one switch, and joining the switch matte and the flexible film. 
     In some embodiments, a key fob is provided, and comprises a flexible film defining an exterior surface of the key fob including at least one contact surface, the at least one contact surface flexing when a force is applied in order to actuate at least one switch included in the key fob, the flexible film including a substantially transparent exterior layer and an inner layer, a back side of the exterior layer being attached to a front side of the inner layer. 
     Some embodiments of the present invention provide a method of forming a key fob, comprising: providing a flexible film having an inner layer and a substantially transparent exterior layer, printing on a front side of the inner layer, and attaching the inner layer to the exterior layer. 
     Other aspects of the present invention will become apparent by consideration of the detailed description and accompanying drawings. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a perspective view of a key fob according to an embodiment of the present invention. 
         FIG. 2  is an exploded perspective view of the key fob of  FIG. 1 . 
         FIG. 3  is a perspective view of the key fob of  FIG. 1 , illustrating a flexible film being depressed to actuate a switch. 
         FIG. 4   a  is a cross-sectional view of the key fob of  FIGS. 1-3 , taken along line  4 - 4  of  FIG. 1 . 
         FIG. 4   b  is a cross-sectional view of an alternative embodiment of the key fob of  FIGS. 1-3 , taken along line  4 - 4  of  FIG. 1 . 
         FIG. 5  is an exploded cross-sectional view of the key fob of  FIGS. 1-3 , taken along line  5 - 5  of  FIG. 1   
         FIG. 6  is a perspective view of the key fob of  FIGS. 1-3 , illustrating a removable mechanical key blade. 
         FIG. 7  is an exploded perspective view of the key fob of an alternative embodiment of  FIG. 1 . 
         FIG. 8  is a perspective view of a key fob according to another embodiment of the present invention. 
         FIG. 9  is a perspective view of a key fob according to another embodiment of the present invention. 
         FIG. 10  is a cross-sectional view of the key fob of  FIG. 7 , taken along line  10 - 10  of  FIG. 7 . 
         FIG. 11   a  is a perspective view of a key fob according to another embodiment of the present invention. 
         FIG. 11   b  is cross-sectional view the key fob of  FIG. 11   a,  taken along line  11 - 11  of  FIG. 11   a.    
         FIG. 12  is an exploded cross-sectional view of the key fob of  FIGS. 11   a - b.    
         FIG. 13  is a cross-sectional view of a key fob according to another embodiment of the present invention. 
         FIG. 14  is an exploded cross-sectional view of the key fob of  FIG. 13 . 
         FIG. 15  are views of an assembly of the flexible film and flexible circuit included in the key fob of  FIGS. 13 and 14 . 
         FIG. 16  are views of an assembly of a flexible circuit and a PCB included in the key fob of  FIGS. 13 and 14 . 
         FIG. 17  are views of an assembly of a flexible film and a flexible circuit included in the key fob of  FIGS. 13 and 14 , according to another embodiment of the present invention. 
         FIG. 18  is a cross-sectional view of a key fob according to yet another embodiment of the present invention. 
         FIG. 19  is an exploded cross-sectional view of the key fob of  FIG. 18 . 
         FIG. 20   a  is a perspective view of a key fob according to another embodiment of the present invention. 
         FIG. 20   b  is a cross-sectional view of the key fob of  FIG. 20   a , taken along line  20 - 20  of  FIG. 20   a.    
         FIG. 21  is an exploded cross-sectional view of the key fob of  FIGS. 20   a - b.    
         FIG. 22  is a cross-sectional view of a key fob according to another embodiment of the present invention. 
         FIG. 23  is an exploded cross-sectional view of the key fob of  FIG. 22 . 
         FIG. 24  is a cross-sectional view of a key fob according to another embodiment of the present invention. 
         FIG. 25  is an exploded cross-sectional view of the key fob of  FIG. 24 . 
         FIG. 26   a  is a perspective view of a key fob according to another embodiment of the present invention. 
         FIG. 26   b  is a cross-sectional view of the key fob of  FIG. 26   a , taken alone line  26 - 26  of  FIG. 26   a.    
         FIG. 27  is an exploded cross-sectional view of the key fob of  FIGS. 26   a - b.    
         FIG. 28  is a cross-sectional view of a key fob according to another embodiment of the present invention. 
         FIG. 29  is an exploded cross-sectional view of the key fob of  FIG. 28 . 
         FIG. 30  is a cross-sectional view of a key fob according to another embodiment of the present invention. 
         FIG. 31  is an exploded cross-sectional view of the key fob of  FIG. 30 . 
         FIG. 32  is a perspective view of a key fob according to an embodiment of the present invention. 
         FIG. 33  is a cross-sectional view of an upper assembly of the key fob of  FIG. 32 , taken along line  33 - 33  of  FIG. 32  according to an embodiment of the present invention. 
         FIG. 34  is an exploded cross-sectional view of the upper assembly of  FIG. 33 . 
         FIG. 35  is a perspective view of a key fob according to an embodiment of the present invention. 
         FIG. 36  is a cross-sectional view of an upper assembly of the key fob of  FIG. 35 , taken along line  36 - 36  of  FIG. 35  according to an embodiment of the present invention. 
         FIG. 37  is an exploded cross-sectional view of the upper assembly of  FIG. 35 . 
         FIG. 38  is a cross-sectional view of the flexible film of the key fob of  FIG. 35 , taken along line  36 - 36  of  FIG. 35 . 
         FIG. 39  is a perspective view of a key fob according to an embodiment of the present invention. 
         FIG. 40  is an exploded cross-sectional view of the key fob of  FIG. 39 . 
         FIG. 41  is a perspective view of an insert included in the embodiment of  FIG. 39 . 
         FIG. 42  is a perspective view of a spider included in the embodiment of  FIG. 39 . 
         FIG. 43  is a perspective view of a housing including a PCB and a spider used in the embodiment of  FIG. 39 . 
         FIG. 44  is a perspective view of a housing, insert and flexible film used in the embodiment of  FIG. 39 . 
         FIG. 45  is a cross-sectional view of the key fob of  FIG. 39 , taken along line  45 - 45  of  FIG. 39 . 
         FIG. 46  is a cross-sectional view of the key fob of  FIG. 39 , taken along line  45 - 45  of  FIG. 39 , showing a portion of a flexible film being pressed. 
         FIG. 47  illustrates an alternative construction of a flexible film, a switch matte, a floating plunger, a switch and a PCB that may be used with other embodiments heretofore described, in particular the embodiments illustrated in  FIGS. 35-46 . 
         FIG. 48  illustrates the construction of  FIG. 47 , showing a portion of a flexible film being pressed. 
         FIG. 49  illustrates an alternative construction of a flexible film, a switch matte, a floating plunger, a switch and a PCB that may be used with other embodiments heretofore described, in particular the embodiments illustrated in  FIGS. 35-46 . 
         FIG. 50  illustrates the construction of  FIG. 49 , showing a portion of a flexible film being pressed. 
         FIG. 51  illustrates an alternative construction of a flexible film, a switch matte, a floating plunger, a switch and a PCB that may be used with other embodiments heretofore described, in particular the embodiments illustrated in  FIGS. 35-46 . 
         FIG. 52  illustrates the construction of  FIG. 51 , showing a portion of a flexible film being pressed. 
         FIG. 53  a perspective view of a key fob according to an embodiment of the present invention. 
         FIG. 54  is a perspective view of the upper housing included in the embodiment of  FIG. 53 . 
         FIG. 55  is a cross-sectional view of the key fob of  FIG. 53 , taken along line  55 - 55  of  FIG. 53 . 
         FIG. 56  a perspective view of a key fob according to an embodiment of the present invention. 
         FIG. 57  is a perspective view of the upper housing included in the embodiment of  FIG. 56 . 
         FIG. 58  is a cross-sectional view of the key fob of  FIG. 56 , taken along line  57 - 57  of  FIG. 56 . 
         FIG. 59  illustrates the PCB included in the embodiment of  FIG. 56 . 
         FIG. 60  is a perspective view of a key fob according to an embodiment of the present invention. 
         FIG. 61  is an exploded cross-sectional view of the key fob of  FIG. 60 . 
         FIG. 62  is a perspective view of an upper housing included in the embodiment of  FIG. 60 . 
         FIG. 63  is a perspective view of the upper housing and a spider included in the embodiment of  FIG. 60 . 
         FIG. 64  is a perspective view of the upper housing and a flexible film included in the embodiment of  FIG. 60 . 
         FIG. 65  is a cross-sectional view of the key fob of  FIG. 60 , taken along line  65 - 65  of  FIG. 60 . 
         FIG. 66  is a cross-sectional view of the key fob of  FIG. 60 , taken along line  65 - 65  of  FIG. 60 , showing a portion of a flexible film being pressed. 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     Before any embodiments of the present invention are explained in detail, it is to be understood that the invention is not limited in its application to the details of construction and the arrangement of components set forth in the following description or illustrated in the accompanying drawings. The invention is capable of other embodiments and of being practiced or of being carried out in various ways. Also, it is to be understood that the phraseology and terminology used herein is for the purpose of description and should not be regarded as limiting. The use of “including,” “comprising,” or “having” and variations thereof herein is meant to encompass the items listed thereafter and equivalents thereof as well as additional items. Unless specified or limited otherwise, the terms “mounted,” “connected,” “supported,” and “coupled” and variations thereof are used broadly, and encompass both direct and indirect mountings, connections, supports, and couplings. Further, “connected” and “coupled” are not restricted to physical or mechanical connections or couplings. 
       FIGS. 1-6  illustrate a key fob  10  according to an embodiment of the present invention. As shown in  FIG. 2 , the key fob  10  can include a housing  12 , a printed circuit board (PCB)  14 , a lid  16 , one or more switches  18 , and a flexible film  20 . The housing  12  can be generally tub-shaped and can be constructed from plastic. In other embodiments, the housing  12  can be constructed from a composite material, a metal, or another suitable material. The housing  12  can include a valet hook  22  for hanging up the key fob  10 . The housing  12  can include a cylindrical recess  24  that can receive a battery  26  and a battery access door  28 . The housing  12  can include an elongated aperture  30  that can receive a mechanical key blade  34 . The housing  12  can include standoffs  36  on an interior portion in order to provide surfaces to support the PCB  14 . The standoffs  36  can help ensure that the PCB  14  is positioned correctly with respect to other components within the key fob  10 . Above or at substantially the same vertical position of the standoffs  36 , a shelf  38  can be defined around the perimeter of the housing  12 . The shelf  38  can provide a surface to support the lid  16  above the PCB  14 . 
     The PCB  14  can be shaped according to the shape of the interior portion of the housing  12 . The PCB  14  can include electrical components that allow the key fob  10  to control various functions of a vehicle. These functions can include, but are not limited to, remotely actuating door locks, a trunk lock, lights, and an ignition. The PCB  14  can include an antenna (not shown), a controller (not shown), and one or more of the switches  18 . The PCB  14  can receive power from the battery  26 . The PCB  14  can be positioned between the standoffs  36  and the lid  16 . 
     As shown in  FIG. 5 , the lid  16  can include one or more standoffs  40  and one or more apertures  42  defined in a sheet of a plastic material. In some embodiments, the lid  16  can be injection molded in order to define the standoffs  40  and the apertures  42 . In other embodiments, the lid  16  can be constructed of metal or another suitable material. The standoffs  40  can contact portions of the PCB  14  away from the electrical components and/or the switches  18 . When the lid  16  is joined to the housing  12 , the standoffs  40  can help hold the PCB  14  in place by pressing the PCB  14  against the standoffs  36  of the housing  12  (as shown in  FIGS. 4 and 5 ). The lid  16  can be positioned above the PCB  14  to allow the switches  18  to be actuated through the apertures  42 . 
     In some embodiments, the switches  18  can be tact switches. For their size, tact switches typically require a relatively high force to actuate the switch. Tact switches also typically have a relatively short stroke (e.g., 0.25 mm) and generate an audible click when actuated. The number of switches  18  included in the fob  10  can be based on each application, such as each make in a family of vehicles. Rather than tact switches, other types of switches or actuators can be used. For example, an electrically-conductive material can be positioned under a contact surface of the flexible film  20  in order to contact two conductive traces on the PCB  14  to complete a circuit. In some embodiments, the switches  18  can be soldered onto the PCB  14  and can be positioned within the apertures  42 , so that the top of the switch  18  is at or slightly below a top surface of the lid  16 . The switches  18  can be actuated through each one of the corresponding apertures  42  in the lid  16 . 
     As shown in  FIG. 2 , the flexible film  20  can include a relatively thin piece of plastic having a perimeter substantially equal to the perimeter of the lid  16  and the housing  12 . In some embodiments, the lid  16  can include a portion extending above the housing  12  as shown in  FIGS. 8 and 9 . In the embodiment shown in  FIG. 8 , the flexible film  20  can have a smaller perimeter than the perimeter of the lid  16 . In the embodiment shown in  FIG. 9 , the flexible film  20  can be thermoformed such that the shape of the flexible film  20  substantially matches the contour of the lid  16 . The flexible film  20  can define contact surfaces  44  above one or more of the apertures  42 . In some embodiments, the flexible film  20  is coupled to the lid  16  by an adhesive. In other embodiments, the flexible film  20  can be coupled to the lid  16  by at least one of injection molding the lid  16  onto the flexible film  20 , laser welding, or sonic welding. In still other embodiments, the flexible film  20  can be coupled to the lid  16  by snap fitting the flexible film  20  to the lid  16 . 
     With reference again to  FIG. 1 , as an example only, the key fob  10  can include three contact surfaces  44  corresponding to three vehicle functions. As shown in  FIG. 2 , the key fob  10  can include three switches  18  corresponding to the three contact surfaces  44 . However, the number of switches  18  and contact surfaces  44  can vary depending on remotely actuated functions required for a particular vehicle. 
     As shown in  FIG. 3 , a switch  18  can be actuated through one of the apertures  42  by pressing a contact surface  44  of the flexible film  20 , which can flex enough to actuate the switch  18 . Due to the positioning of the switch  18  and its short stroke, the flexible film  20  only needs to flex a minimal distance to actuate the switch  18 . The life of the flexible film  20  can be extended by using switches with a short stroke that only requires the flexible film  20  to flex a minimal distance. The audible and tactile click of the switch  18  can alert the operator that the switch  18  has been depressed. 
     In some embodiments, the flexible film  20  can be screen printed on one or both sides in order to add stylized graphics, contact surfaces, textures, and the like in any combination on the interior and/or exterior surfaces of the flexible film  20 . In some embodiments, the flexible film  20  can be screen printed or otherwise stylized on an interior side in order to provide graphics, contact surfaces, or textures less susceptible to fading and wearing than graphics, contact surfaces, and textures printed on an exterior side of the flexible film  20 . For example, words or graphics defining contact surfaces  44  can be printed on an interior surface of the flexible film  20 , and textures can be printed on an exterior surface of the flexible film  20 . In other embodiments, multiple flexible films  20  can be layered to add stylized graphics, contact surfaces, textures, and the like to the key fob  10 . For example, the key fob  10  can include a first flexible film printed with a background color for the key fob  10 . A second flexible film printed with graphics, text, and the like can then be placed on top of the first flexible film. The second flexible film can include substantially transparent portions in order to display the color, graphics, text, textures, patterns, and the like printed on the first flexible film. 
     In some embodiments, each individual flexible film  20  is die-cut to shape from a sheet of flexible film. Also in some embodiments, the flexible film  20  can be constructed from a clear polycarbonate resin. The flexible film  20  can be relatively thin (e.g., approximately 0.4-0.5 mm thick). Screen printing can be used to provide high resolution printing in a single or multiple layers at a relatively low cost. Other embodiments can use other methods of customizing the flexible film  20 , such as laser printing, colored films, decals, and the like. 
     In addition to printing graphics and contact surfaces  44  on the flexible film  20 , it is possible to print a rail of thicker ink around the contact surfaces  44  to provide a tactile boundary for one or more contact surfaces  44 . Additionally, more plastic or polydoming material can be located within or outside of (e.g., poured into or around) the rail of thicker ink to fill in and/or dome the contact surface  44  or to otherwise change the contour of the contact surface  44  or area(s) surrounding the contact surface  44 . For example, where additional material is placed within a rail of thicker ink, a domed surface can be formed to correspond to one or more of the switches  18 . A domed surface can also be created using embossing techniques. Similar techniques for providing tactile surfaces on the flexible film  20  can also be used to provide surfaces replicating rubber, leather, wood, metal, fabric, and the like. For example, in some embodiments, the flexible film  20  can be printed with a metallic-based paint or substance, such as chrome and/or aluminum paint, in order to provide a pseudo chrome surface on the key fob  10 . As discussed above, such surfaces can be defined on either or both sides of the flexible film  20 . 
     In some embodiments, the flexible film  20  can have raised contact surfaces  44  created by thermoforming the flexible film  20 . Thermoforming can include heating the flexible film  20  and applying a vacuum between the flexible film  20  and a die representative of a desired shape for the contact surface  44 . In some embodiments, the lid  16  can be formed with a domed shape, and the flexible film  20  can be thermoformed to match the domed shape of the lid  16 , as shown by way of example in  FIG. 4   b . As shown, for example, in  FIGS. 56-63  and described below, the flexible film  20  can also be shaped to provide beveled or faceted edges, grooves, and/or other shapes. Such shapes can be made by thermoforming the flexible film  20  or by other suitable methods. 
     Screen printing of the flexible film  20  can allow for customized styling of the key fob  10  for different vehicles, but for use with the same housing  12 , PCB  14 , and lid  16 . In some embodiments, another flexible film can be coupled to the underside of the housing  12  to add additional stylized graphics and/or textures to the key fob  10 . 
     The number of switches  18  in each key fob  10  can vary. However, in some embodiments, the number of apertures  42  in the lid  16  can be the same for each key fob  10 . For example, the lid  16  can include enough apertures  42  for the maximum number of functions that can be controlled for any make in a family of vehicles. However, the number of switches  18  and contact surfaces  44  can be the same as or less than the number of apertures  42  in the lid  16 . For a vehicle make, the desired number of switches  18  can be soldered to the PCB  14  in desired locations. When the flexible film  20  is screen printed, a contact surface  44  can be printed to be positioned over each switch  18  on the PCB  14 . The flexible film  20  can be pressed and flexed over the apertures  42  that do not include a switch  18 , but the flexible film  20  can be sufficiently resilient to spring back without a switch  18  forcing it back. If desired, the lid  16  can be redesigned at minimal cost to eliminate the apertures  42  in the lid  16  where a switch  18  is not needed. 
       FIGS. 4   a ,  4   b , and  5  illustrate cross-sections of the key fob  10 . The key fob  10  can be assembled almost entirely in a single position, meaning that the components do not need to be turned over until the end of the assembly, which speeds the process and lowers costs. The PCB  14  (which can include the necessary electronic components and required number of switches  18  for the particular vehicle model) can be placed into the housing  12  so that the PCB  14  rests on the standoffs  36  in the housing  12 . The lid  16  can be placed on top of the PCB  14 . Depending on the manufacturing process chosen for the lid  16 , the lid  16  can be separate from the flexible film  20  or already joined to the flexible film  20  (such as by injection molding or another suitable process as described above). If the flexible film  20  is not already joined to the lid  16 , the flexible film  20  can be placed on top of the lid  16  and joined to the lid  16  by adhesive, laser welding, sonic welding, or by another suitable method in order to form a watertight seal between the lid  16  and the flexible film  20 . 
     In some embodiments, laser welding can be used to join the lid  16  to the housing  12 . For example, a portion of the flexible film  20  and the lid  16  can be constructed of a material that transmits energy from the laser, while a portion of the housing  12  can be constructed of a material that absorbs energy from the laser. As shown in  FIGS. 4   a  and  4   b , the laser beam can be transmitted through the flexible film  20  and the lid  16  and absorbed by the housing  12  at a point  46  in order to heat the shelf  38  of the housing  12  to its melting point. This can cause the shelf  38  of the housing  12  to bond to the lid  16  and, in some embodiments, to the flexible film  20 . If laser welding is used, a transparent region can be left around the perimeter of the flexible film  20  through which energy can be transmitted from the laser. For example, in some embodiments, that portion of the flexible film  20  that will be attached to the lid  16  and housing  12  can be made from a clear material, and that portion of the lid  16  that will be attached to the flexible film  20  and housing  12  can be made from an opaque white material (both of which can transmit energy from the laser), while the housing  12  can be made from a material that is substantially black or has a darker color and absorbs energy from the laser. In other embodiments, the housing  12  can be joined to the lid  16  and the flexible film  20  with an adhesive, by sonic welding, or by another suitable method capable of forming a watertight seal between the housing  12 , the lid  16 , and the flexible film  20 . 
     After most of the components have been assembled, the key fob  10  can be turned over to install the battery  26  and the removable battery access door  28 . The battery access door  28  can snap into the housing  12  and can be sealed against the housing  12  with an o-ring  48  in the cylindrical aperture  24 . In some embodiments, the cylindrical aperture  24  and the o-ring  48  can be used in all the key fobs  10  for a line of vehicles, and the battery access door  28  can have any one of a variety of shapes (e.g., square, round, covering the entire back of the key fob  10 , irregular shapes, and the like) for each vehicle make. The battery access door  28  can also include, for example, a mirror, a company logo, or other stylized graphics for a particular vehicle make. In some embodiments, screen printed film can be coupled to the battery access door  28  to provide the stylized graphics or the company logo. 
       FIG. 6  illustrates a mechanical key blade  34  that can be stored in the housing  12 . The mechanical key blade  34  can be used to manually operate the door locks, ignition, trunk, and the like. The mechanical key blade  34  can include a relatively small head with an aperture  50  for attaching the mechanical key blade  34  to a key ring, or other device. As shown in  FIG. 2 , the mechanical key blade  34  can slide into the elongated aperture  30  in the housing  12  and can be held in place by a release button  51  on the housing  12  that can engage a recess  52  on the mechanical key blade  34 . The release button includes a protrusion  53  that engages the recess  52 . A spring  55  biases the release button  51  toward a position wherein the mechanical key blade  34  is retained within the housing  12 . The illustrated mechanical key blade  34  can be released by depressing the release button  51 , which disengages the protrusion  53  from the recess  52 . In some embodiments, when the mechanical key blade  34  is inserted into the elongated aperture  30 , the head can cover the valet hook  22 . When the mechanical key blade  34  is removed from the housing  12 , the valet hook  22  can be exposed, allowing the key fob  10  to be hung. In some embodiments, the mechanical key blade  34  can be held in the elongated aperture  30  tightly enough by the release button  51  that the key fob  10  can be carried on a key ring via the aperture  50  in the head. This arrangement allows the operator to detach the key fob  10  from the mechanical key blade  34 , which can remain on the operator&#39;s key ring, in order to provide only the key fob  10  to a valet. In some embodiments, the key fob  10  can be used to actuate the vehicle&#39;s ignition, but not to open the vehicle&#39;s trunk, glove box, and/or other secure area. This is particularly useful if the operator wishes to have the car parked by a valet. The valet can use the key fob  10  to unlock the doors, drive, park, and lock the doors, but the valet cannot access the trunk. Numerous other scenarios may arise in which the operator wishes to detach the key fob  10  for vehicle use, but retain the mechanical key blade  34 . 
       FIG. 7  illustrates the key fob  10  in an alternative embodiment. The embodiment of  FIG. 7  is substantially identical to the embodiment of  FIGS. 1-6 , but includes dome switches  60  rather than the tact switches  18  of  FIGS. 1-6 , and has a lid  16  modified for use with dome switches  60 . The dome switches  60  can have a much lower profile than the tact switches  18 , and thus can require actuators  62  positioned within the apertures  42  of the lid  16  to be actuated. When an operator applies force to a contact surface  44 , the flexible film  20  transfers the force to the actuator  62 . The actuator  62  is flexible, and will bend enough to actuate the dome switch  60 . In some embodiments, the actuators  62  are integrally formed with the lid  16 , whereas in other embodiments, the actuators  62  can be separate elements attached to the lid  16  within the apertures  42  in any suitable manner. 
     The actuators  62  are biased away from the dome switches  60 , such that when an operator removes the force applied to the contact surface  44 , the actuator  62  will retract from the dome switch  60 . In the illustrated embodiment of  FIG. 7 , an actuator  62  can be positioned in every aperture  42  of the lid  16 . Similar to the tact switches  18  described earlier, the number of dome switches  60  can vary between key fobs  10 . To reduce costs associated with manufacturing key fobs  10 , actuators  62  can be positioned in each aperture  42  of the lid  16 , whether or not a dome switch  60  is positioned within the aperture  42 . This means that only one lid  16  needs to be manufactured for any key fob  10 , regardless of the number of dome switches  60  that are included in the key fob  10 . If dome switches  60  and actuators  62  are used in conjunction with a dome-shaped lid  16  (as in  FIG. 4   b , for example), longer actuators  62  can be used to ensure that the actuator  62  flexes to engage the dome switch  60 , which is generally centered in the aperture  42 .  FIG. 10  illustrates a cross-sectional view of the key fob  10  of  FIG. 7 . In some embodiments, the key fob  10  of  FIG. 7  can be assembled as described above with respect to the key fob of  FIGS. 1-6  (see  FIGS. 4   a ,  4   b , and  5 ). 
       FIG. 11   a  illustrates a key fob  10  according to another embodiment of the present invention. As shown in  FIG. 11   a , the illustrated key fob  10  includes a housing  12  and a flexible film  20  including a plurality of contact surfaces  44 . The housing  12  illustrated in  FIG. 11   a  includes a lower housing  12   a  and an upper housing  12   b.  The lower housing  12   a  covers a lower portion of the key fob  10 , and the upper housing  12   b  covers an upper portion of the key fob  10 . Although the lower housing  12   a  and the upper housing  12   b  are shown in  FIG. 11   a  as each covering approximately one half of the thickness of the key fob  10 , other ratios can be used. For example, in some embodiments, the lower housing  12   a  can define approximately 75% of the thickness of the key fob  10  and the upper housing  12   b  can define approximately 25% of the thickness of the key fob  10 . 
     In some embodiments, the lower housing  12   a  can be generally tub-shaped as the housing  12  described above with respect to  FIGS. 1-6 . Similarly, as described above, the lower housing  12   a  can include a cylindrical recess  24  that can receive a battery  26  and a battery access door  28 . In addition, the lower housing  12   a  can include standoffs (not shown) on an interior portion in order to provide surfaces to support a PCB  14 . Furthermore, the lower housing  12   a  can include an elongated aperture (not shown) that can receive a mechanical key blade  34  as described above with respect to  FIG. 6 . 
     As shown in  FIG. 11   a , the illustrated upper housing  12   b  includes an opening  70  and a rim  71 . In some embodiments, the rim  71  extends around the perimeter of the opening  70  and covers at least a portion of the flexible film  20 . Therefore, the rim  71  can frame at least a portion of the flexible film  20  within the opening  70 . In other embodiments, the rim  71  can include one or more tabs that extend from the perimeter of the opening  70  and cover at least a portion of the flexible film. Through the opening  70 , a user can apply force to one or more of the contact surfaces  44  provided on the flexible film  20 . In some embodiments, the opening  70  can include a substantially transparent flexible cover  71   a  (e.g., a substantially transparent film, see  FIG. 12 ). The flexible cover  71   a  can protect the flexible film  20  and other components of the key fob  10  from dust, debris, and moisture, while still allowing a user to view and apply force to the contact surfaces  44  provided on the flexible film  20 . 
     The lower housing  12   a  and the upper housing  12   b  can be constructed from plastic, rubber, silicone, or another suitable material. In other embodiments, the lower housing  12   a  and the upper housing  12   b  can be constructed from a composite material, a metal, or another suitable material. In some embodiments, the lower housing  12   a  and the upper housing  12   b  can be constructed from different materials. The lower housing  12   a  and the upper housing  12   b  can be joined using a snap or force fit. The lower housing  12   a  and the upper housing  12   b  can also or instead be joined using an adhesive bonding material, laser welding, sonic welding, or by another suitable method. For example, as described above with respect to  FIGS. 1-6 , the lower housing  12   a  and the upper housing  12   b  can be laser welded by passing a laser through at least a portion of the flexible film  20 . When joined, the lower housing  12   a  and the upper housing  12   b  can form a watertight seal between the lower housing  12   a  and the upper housing  12   b.    
       FIGS. 11   b  and  12  are cross-sectional views the key fob of  FIG. 11   a  taken along line  11 - 11  of  FIG. 11   a  according to an embodiment of the invention. As shown in  FIGS. 11   b  and  12 , the illustrated key fob  10  includes an upper housing  12   b,  a flexible film  20 , a spacer layer  72 , a PCB  14  with one or more switches (e.g., one or more dome switches  60 ), a battery  26 , a lower housing  12   a,  and a removable battery access door  28 . Similar to the lid  16  described above with respect to  FIGS. 1-10 , the spacer layer  72  defines one or more apertures  42 , which align with one or more switches  60  on the PCB  14 . Although the spacer layer  72  can be constructed of any of the materials described above in connection with the lid  16  of the earlier-described embodiments, the illustrated spacer layer  72  is constructed from one or more layers of flexible film, similar to the flexible film  20 . For example, the spacer layer  72  can be die-cut from a sheet of composite film layers. As compared to injection molding, processes such as cutting, die-cutting, stamping, or punching the spacer layer  72  from a sheet of material allows the position and number of apertures  42  to be modified relatively easily and inexpensively. 
     Similar to the key fobs of  FIGS. 1-10 , in some embodiments, the key fob  10  of  FIGS. 11   a ,  11   b , and  12  can be constructed almost entirely in a single position. Therefore, the key fob components do not need to be turned over until the end of assembly, which can speed the manufacturing process and lower manufacturing costs. For example, the key fob  10  of  FIGS. 11   a ,  11   b  and  12  can be back assembled or loaded (e.g., assembled through the back of the key fob  10 ) by initially placing the flexible film  20  into the upper housing  12   b.  As noted above, the rim  71  of the upper housing  12   b  can cover a portion of the flexible film  20  and can hold the flexible film  20  (and additional interior components) within the key fob  10 . In some embodiments, the flexible film  20  can be joined to an interior surface of the upper housing  12   b  (e.g., the rim  71 ) in any of the manners described above, such as by using adhesive bonding, laminating, or another suitable method. After the flexible film  20  is installed in the upper housing  12   b,  the spacer layer  72  can be joined to an interior surface of the flexible film  20  using adhesive bonding material, or by another suitable method (including those described above in connection with the flexible film-to-lid attachment methods of earlier-described embodiments). In some embodiments, the flexible film  20  and the spacer layer  72  are joined before installing the components within the upper housing  12   b.  For example, the flexible film  20  can be joined with the spacer layer  72  by adhesive bonding or another suitable method. Once the flexible film  20  and the spacer layer  72  are assembled, the resulting assembly can be placed within the upper housing  12   b.    
     After the flexible film  20  and the spacer layer  72  are installed in the upper housing  12   b,  the PCB  14  can be installed. In some embodiments, the PCB  14  can be joined to the spacer layer  72  by adhesive bonding or another suitable method. Also in some embodiments, the flexible film  20 , spacer layer  72 , and PCB  14  can be assembled together prior to installation within the upper housing  12   b  as a single unit. Next, the lower housing  12   a  can be joined with the upper housing  12   b,  and the battery  26  and the battery access door  28  can be installed. As noted above, the lower housing  12   a  and the upper housing  12   b  can be laser welded, for example, by passing a laser through a portion of the flexible film  20  and the spacer layer  72 . In other embodiments, the lower housing  12   a  and the upper housing  12   b  can be joined using a snap or force fit, by adhesive, or another suitable method. In some embodiments, if the lower housing  12   a  includes standoffs on an interior portion to provide supporting surfaces for the PCB  14 , the standoffs can be aligned with the PCB  14  when the lower housing  12   a  is joined with the upper housing  12   b.  Adhesive bonding can also be used to join the PCB  14  with the standoffs. It should be understood that in addition to or in place of using adhesive bonding or another similar methods, one or more of the components of the key fob  10  can be assembled using a force or pressure fit. For example, a force provided by the lower housing  12   a  joined with the upper housing  12   b  can be applied to the internal components of the key fob  10  to hold all or a subset of the components in place within the key fob  10 . It should be noted that the interior components and configuration described with respect to the embodiment of  FIGS. 11   a,    11   b  and  12  can also be used with other exterior key fob configurations, such as the configurations described above with respect to  FIGS. 1 ,  4   b ,  8 , and  9 . Similarly, the exterior fob components and configuration described with respect to the embodiment of  FIGS. 11   a ,  11   b,  and  12  can also be used with other interior components and configurations, such as the configurations described above with respect to  FIGS. 1-6 ,  7 , and  10 . 
       FIGS. 13 and 14  illustrate cross-sectional views of a key fob  10  according to a further embodiment of the invention. In some embodiments, the exterior of the key fob  10  of  FIGS. 13 and 14  is similar to the exterior of the key fob  10  illustrated in  FIG. 11   a.  It should be understood, however, that the interior components of the key fob  10  illustrated in  FIGS. 13 and 14  can be used with other exterior configurations, such as the configurations described above with respect to  FIGS. 1 ,  4   b ,  8 , and  9 . 
     As shown in  FIGS. 13 and 14 , the illustrated key fob  10  includes an upper housing  12   b,  a flexible film  20 , a spacer layer  72 , a flexible circuit  74  including one or more switches, one or more connectors  76 , a PCB  14 , a lower housing  12   a,  a battery  26 , and a removable battery access door  28 . As described above with respect to  FIGS. 11   a,    11   b  and  12 , the spacer layer  72  defines one or more apertures  42  for receiving a switch  60 . However, as shown in  FIGS. 13 and 14 , rather than or in addition to placing switches (e.g., tact or dome switches) on the PCB  14 , the flexible circuit  74  includes one or more switches  60 . For example,  FIG. 15  is an exploded cross-sectional view of an assembly  77  of the flexible film  20  and the flexible circuit  74  of  FIGS. 13 and 14  according to an embodiment of the present invention. As shown in  FIG. 15 , the flexible circuit  74  can include one or more switches  60  (e.g., a snap dome switch, a tact switch, a tactless membrane switch, and the like) that align with the apertures  42  in the spacer layer  72 . Therefore, a user can actuate a switch  60  on the flexible circuit  74  by applying a force to a contact surface  44  on the flexible film  20 , which flexes within one of the apertures  42  defined in the spacer layer  72  and actuates the switch  60 . 
     In some embodiments, the flexible circuit  74  is die-cut or otherwise stamped, punched, or cut from a sheet of flexible material (e.g., plastic). The flexible material can include multiple layers. For example, the switches  60  can be positioned between two or more layers of flexible material. As shown in  FIG. 15 , each switch  60  also includes at least two electrical traces  82  (e.g., a power or signal trace  82   a  and a ground trace  82   b ). Like the switches  60 , each electrical trace  82  can be positioned between two or more layers of flexible material. In some embodiments, the electrical traces  82  are constructed by printing or providing conductive material on the surface of a layer of flexible material. 
     As shown in  FIG. 15 , each electrical trace  82  can end at a contact patch  84 . Each contact patch  84  provides an external electrical connection point or terminal for the electrical traces  82  on the flexible circuit  74 . Therefore, each switch  60  on the flexible circuit  74  can be associated with at least one contact patch  84 . Accordingly, each contact patch  84  can be associated with a particular function to be executed when the user actuates a particular switch  60  on the key fob  10 . For example, a first contact patch  84  on the flexible circuit  74  can be associated with unlocking a vehicle door and a second contact patch  84  can be associated with unlocking the vehicle door. As shown in  FIG. 15 , the flexible circuit  74  can also include a common ground electrical trace  82   b  and an associated common ground contact patch  84   b.    
     In some embodiments, the contact patch  84  for each electrical trace  82  on the flexible circuit  74  can be positioned within a common location. For example, as shown in  FIG. 15 , each contact patch  84  can be positioned along a common edge of the flexible circuit  74  (e.g., to one common side of the key fob  10 ), or can be positioned in any other common area of the flexible circuit  74  (e.g., a middle portion of the key fob  10 ). It should be understood that the flexible circuit  74  can include additional or fewer contact patches  84  than those illustrated in  FIG. 15 . 
       FIG. 16  illustrates an assembly  85  including the flexible circuit  74  and the PCB  14  included in the key fob  10  of  FIGS. 13 and 14  according to an embodiment of the present invention. As shown in  FIG. 16 , the contact patches  84  of the flexible circuit  74  are connected to contact patches  86  on the PCB  14  through one or more connectors  76 . Similar to the contact patches  84  of the flexible circuit  74 , each contact patch  86  on the PCB  14  can be associated with a particular function to be executed when a user actuates a particular switch  60 . Although not shown in  FIG. 16 , the contact patches  86  on the PCB  14  are connected to electrical traces within the PCB  14  that carry any electrical signals received on the contact patches  86  to the proper components (e.g., the controller) installed in the PCB  14 . 
     In some embodiments, the contact patches  86  on the PCB  14  can be positioned in the same common location as the contact patches  84  of the flexible circuit  74 . For example, as shown in  FIG. 16 , the contact patches  86  can be positioned along a common edge of the PCB  14 . Similarly, the contact patches  86  on the PCB  14  can be positioned in a similar order as the contact patches  84  of the flexible circuit  74 . For example, a first contact patch on the edge of both the flexible circuit  74  and the PCB  14  can be associated with the same function, such as locking a vehicle door, unlocking a vehicle door, and the like. 
     As shown in  FIG. 16 , the connector  76  can be positioned between the flexible circuit  74  and the PCB  14 . The connector  76  generally connects one or more contact patches  84  of the flexible circuit  74  with corresponding contact patches  86  on the PCB  14 . In some embodiments, the connector  76  includes one or more elastomeric connectors, such as those manufactured by Fujipoly America Corporation® of Carteret, N.J. under the name Zebra® Elastomeric Connector. In other embodiments, the connector  76  is an electrically conductive adhesive transfer tape, such as those manufactured by 3M Corporation® of St. Paul, Minn. Other types of connectors  76  are possible, and fall within the spirit and scope of the present invention. 
     The connector  76  provides redundant electrical paths for connecting electrical components. For example, in some embodiments, the connector  76  includes a plurality of alternating conductive and non-conductive (i.e., insulating) sections or paths. When the connector  76  is joined with an electrical component, if a conductive section of the connector  76  aligns with an electrical path or terminal of the electrical component, the connector  76  passes any signal received on the electrical terminal of the electrical component through the aligned conductive section. In this sense, when the connector  76  is positioned between the flexible circuit  74  and the PCB  14 , the connector  76  passes any electrical signals received from contact patches  84  on the flexible circuit  74  that align with any of its conductive sections to the contact patches  86  on the PCB  14  that also align with the same conductive sections. 
     In some embodiments, the connector  76  is self-adhesive, and is pressure-activated. Therefore, the connector  76  can be joined to the flexible circuit  74  and the PCB  14  through a pressure fit that activates the adhesive. Also, elastomeric connectors  76  (described above) can be used to bridge gaps between the flexible circuit  74  and the PCB  14 , as they can have any shape and thickness desired. The self-adhesive feature of many transfer tape connectors and elastomeric connectors can increase the speed and efficiency of assembling the key fob  10  and, consequently, can reduce the cost of the key fob  10 . Similarly, in some embodiments, the connector  76  can include a greater number of alternating conductive and non-conductive sections than the number of contact patches  84 ,  86  such that multiple conductive sections can align with a contact patch  84  or  86 . This feature can increase the ease of assembling the key fob  10 , because as long as one conductive section of the connector  76  aligns with a single contact patch  84  on the flexible circuit  74  and the corresponding contact patch  86  on the PCB  14 , an electrical connection is established between the flexible circuit  76  and the PCB  14 . Therefore, some degree of mismatch between the flexible circuit  74 , the connector  76 , and the PCB  14  can be tolerated during assembly and afterwards (e.g., if components of the key fob  10  shift). 
     As described above with respect to  FIGS. 11   a ,  11   b  and  12 , by die-cutting, stamping, punching, or otherwise cutting the spacer layer  72 , the number and locations of contact surfaces  44  can be varied relatively easily and inexpensively. Similarly, by combining the spacer layer  72  with a die-cut flexible circuit  74 , the number and locations of the associated switches can also be easily and inexpensively modified. Furthermore, by providing a separate, easily changeable flexible circuit  74 , a common PCB  14  can generally be used in a key fob  10  even as the number and/or locations of contact surfaces  44 , apertures  42 , and associated switches  60  changes. As shown in  FIGS. 13 and 14 , the switches  60  can be removed from the PCB  14  by placing them on the flexible circuit  74 . This feature can further lower the cost of the key fob  10 . Another aspect of the embodiment of  FIGS. 13-16  is the increased ability to easily select the number of positions of the contact surfaces  44  as needed without changing the PCB  14 . As with the embodiment of  FIG. 17  described below, the use of the connector  76  and the location of the switches  60  on the flexible circuit enables this advancement. 
       FIG. 17  illustrates an alternative assembly  77  of the flexible film  20  and flexible circuit  74  for the key fob of  FIG. 13  according to another embodiment of the present invention. As shown in  FIG. 17 , the flexible circuit  74  can include one or more light emitting diodes (“LEDs”)  88 . The LEDs  88  can be positioned on the flexible circuit  74 , and can be located between two or more sheets of flexible material and/or can be surface-mounted on the flexible circuit  74 . As shown in  FIG. 17 , in some embodiments the flexible circuit  74  can include one or more LEDs  88  around one or more switches  60 . In other embodiments, the flexible circuit  74  can include one or more LEDs  88  positioned separate from a switch  60 . As shown in  FIG. 17 , the flexible film  20  can include a corresponding LED surface  92  for one or more LEDs  88 . In some embodiments, the flexible film  20  can include a LED surface  92  similar in size to a single LED  88 . In other embodiments, the flexible film  20  can include a LED surface  92  smaller than or greater than the size of a single LED  88 . The LED surface  92  is back-lit when the LED  88  is illuminated. In some embodiments, the LED surface  92  can be stylized in a manner different from other portions of the flexible film  20 . For example, the LED surface  92  can be substantially transparent, can be colored, and/or can include a graphic or text. 
     As shown in  FIG. 17 , similar to the switches  60 , the LEDs  88  can include electrical traces  82  ending at contact patches  84 . As described above, the contact patches  84  are connected to contact patches  86  on the PCB  14  through the connector  76 . Therefore, the PCB  14  can control when one or more of the LEDs  88  are illuminated. The LEDs  88  can operate in various manners. For example, an LED  88  can be illuminated when a switch  60  is actuated. Therefore, one or more LEDs  88  can alert a user that he or she has actuated a switch  60  on the key fob  10 . In other embodiments, the key fob  10  can receive feedback from the vehicle and can display the feedback to the user using the LEDs  88 . For example, if the user actuates the “lock” switch  60  on the key fob  10 , the key fob  10  can transmit a “lock” signal to the vehicle and can wait to receive a “lock confirmed” signal from the vehicle. The vehicle can generate and transmit a “lock confirmed” signal once it locks one or more doors (e.g., sends a lock signal to a lock controller) and/or once it verifies that the one or more doors have actually locked (e.g., receives signals from one or more sensors). Once the key fob  10  receives a “lock confirmed” signal, the key fob  10  can illuminate one or more of the LEDs  88 . Therefore, the key fob  10  can participate in two-way communication with the vehicle and can present feedback information to a user. 
     It should be understood that, in some embodiments, multiple connectors  76  can be used to connect the flexible circuit  74  and the PCB  14 . For example, as shown in  FIGS. 18 and 19 , a connector  76  can be used for each contact patch  84  on the flexible circuit  74 . Using this configuration, each contact patch  84  on the flexible circuit  74  can be connected to a contact patch  86  on the PCB  14  where a corresponding switch  80  would be if not provided in the flexible circuit  74 . Therefore, in some embodiments, this configuration allows the flexible film  20 , the spacer layer  72 , and the flexible circuit  74  to be used in a key fob without substantially modifying the PCB  14  previously used in the key fob. Also, regardless of whether one connector  76  is used or whether multiple connectors  76  are used, the number of positions of the switches  44  and LEDs  88  can be changed in many embodiments without changing the PCB  14 . 
     As described above with respect to  FIG. 12 , the key fob  10  illustrated in  FIGS. 13-17  can be assembled almost entirely in a single position. For example, as described above, the key fob  10  can be back loaded or assembled by initially placing the flexible film  20  into the upper housing  12   b.  As noted above, the rim  71  of the upper housing  12   b  can cover a portion of the flexible film  20  and hold the flexible film  20  (and additional interior components) within the key fob  10 . In some embodiments, the flexible film  20  can be joined to an interior surface of the upper housing  12   b  (e.g., the rim  71 ) using adhesive bonding, laminating, or another suitable method. After the flexible film  20  is installed in the upper housing  12   b,  the spacer layer  72  can be joined to an interior surface of the flexible film  20  using adhesive bonding or another similar method. The flexible circuit  74  can be joined to an interior surface of the spacer layer  72  using adhesive bonding or by another suitable method. Next, the one or more connectors  76  and the PCB  14  can be installed in the upper housing  12   b.  As noted above, in some embodiments, the one or more connectors  76  include a self-adhesive that is actuated by pressure applied by the flexible circuit  74  and the PCB  14 . The PCB  14  can also be joined to the flexible circuit  74  using adhesive bonding or by another suitable method. 
     In some embodiments, the flexible film  20 , the spacer layer  72 , and the flexible circuit  74  can be constructed as an assembly before installing the components in the upper housing  12   b  as a single integral unit. For example, the flexible film  20 , the spacer layer  72 , and the flexible circuit  74  can be joined using a laminating process or by another suitable method. Once constructed, the assembly can be placed within the upper housing  12   b.  In some embodiments, the assembly (i.e., the flexible film  20 , the spacer layer  72 , and the flexible circuit  74 ) can be joined to the upper housing  12   b  using adhesive bonding, or in any other suitable manner. For example, as shown in  FIG. 13 , an adhesive can be applied in corners  93  within the upper housing  12   b  adjacent the assembly. In some embodiments, the one or more connectors  76  can also be attached to the assembly using adhesive bonding or by another suitable method before the assembly is installed in the upper housing  12   b.    
     After the flexible film  20 , the spacer layer  72 , the flexible circuit  74 , the one or more connectors  76 , and the PCB  14  are installed in the upper housing  12   b,  the lower housing  12   a  can be joined with the upper housing  12   b,  and the battery  26  and the battery access door  28  can be installed. As noted above, the lower housing  12   a  and the upper housing  12   b  can be laser welded by passing a laser through a portion of the flexible film  20 , the spacer layer  72 , and/or the flexible circuit  74 . In other embodiments, the lower housing  12   a  and the upper housing  12   b  can be joined using a snap or force fit, an adhesive, or another suitable method. In some embodiments, if the lower housing  12   a  includes standoffs on an interior portion to provide supporting surfaces for the PCB  14 , the standoffs can be aligned with the PCB  14  when the lower housing  12   a  is installed. Adhesive bonding can also be used to join the PCB  14  with the standoffs. It should be understood that in addition to or in place of using adhesive bonding or other similar connection methods, one or more of the components of the key fob  14  can be assembled using a force or pressure fit. For example, force provided by the lower housing  12   a  joined with the upper housing  12   b  can be applied to the internal components of the key fob  10  to hold all or a subset of the components in place. 
       FIG. 20   a  is a perspective view of a key fob  10  according to another embodiment of the present invention. As shown in  FIG. 20   a , the illustrated key fob includes a flexible film  20  and a housing  12  including a lower housing  12   a  and an upper housing  12   b.  As also shown in  FIG. 20   a , rather than having a rim  71  overlapping an outer edge of the flexible film  20  as described above with respect to  FIG. 11   a,  the upper housing  12   b  illustrated in  FIG. 20   a  includes a frame  94  surrounding an outer edge of the flexible film  20 . As shown in  FIG. 20   b , the frame  94  is at substantially the same height as the flexible film  20 . It should be understood, however, that the frame  94  can be constructed to be at a greater or lesser height than the height of the flexible film  20 . For example, the height of the flexible film  20  can be lower than the height of the frame  94  in order to reduce the opportunity for an edge of the flexible film  20  to catch on external objects and potentially being inadvertently removed and/or damaged. In some embodiments, the frame  94  can also include a lip (not shown) that overlaps an outer edge of the flexible film  20  to further prevent the flexible film  20  from being inadvertently removed and/or damaged. 
       FIGS. 20   b  and  21  are cross-sectional views of the key fob of  FIG. 20   a , taken along line  20 - 20  of  FIG. 20   a . As shown in  FIGS. 20   b  and  21 , the illustrated key fob  10  includes an upper housing  12   b,  a flexible film  20 , a spacer layer  72 , a flexible circuit  74 , a connector  76 , a PCB  14 , a battery  26 , a lower housing  12   a,  and a removable battery access door  28 . As described above with respect to  FIGS. 13-19 , the flexible film  20 , the spacer layer  72 , and the flexible circuit  74  define the number and locations of switches  60  and the associated contact surfaces  44  on the key fob  10 . In some embodiments, because most of these components can be die-cut (e.g., rather than injection molded), they can be easily and inexpensively modified to adapt each fob for different functionality. As also described above with respect to  FIGS. 13-19 , a connector  76 , such as an elastomeric connector, connects contact patches on the flexible circuit  74  to contact patches on the PCB  14 . Therefore, in some embodiments, even as the locations and number of switches  60  on the flexible circuit  74  change, the PCB  14  does not need to change. In addition, in this configuration, the PCB  14  does not require any switches, which lowers the cost of the PCB  14 . 
     As shown in  FIG. 21 , the illustrated upper housing  12   b  includes a recess  95  and a lower surface  96 . The recess  95  receives the flexible film  20 , the spacer layer  72 , and the flexible circuit  74 , which are supported by the lower surface  96 . In some embodiments, the flexible circuit  74  is joined to the lower surface  96  using adhesive bonding or by another suitable method. In this sense, as compared to the rim  71  of the upper housing  12   b  of  FIGS. 11   b  and  12 - 14 , the lower surface  96  provides a large area for supporting and securing the flexible film  20 , the spacer layer  72 , and the flexible circuit  74  within the upper housing  12   b.    
     As also shown in  FIG. 21 , the lower surface  96  of the upper housing  12   b  includes an opening  98 . The opening  98  receives the connector  76 , which electrically connects the flexible circuit  74  with the PCB  14 . Therefore, in some embodiments, the contact patches on the flexible circuit  74  are aligned with the opening  98 . Similarly, the contact patches on the PCB  14  are aligned with the opening  98 . The connector  76  can be placed within the opening  98  to connect the contact patches of the flexible circuit  74  with the contact patches of the PCB  14 . It should be understood that the opening  98  (and associated contact patches) can be positioned anywhere along the lower surface  96  of the upper housing  12   b.  Similarly, multiple openings  98  and connectors  76  can be provided to connect the flexible circuit  74  and the PCB  14 . For example, as shown in  FIGS. 22 and 23 , in some embodiments, an opening  98  in the lower surface  96  and an associated connector  76  can be provided for each contact patch on the flexible circuit  74 . Using this configuration, each contact patch on the flexible circuit  74  can be connected to a contact patch on the PCB  14  where a corresponding switch  60  would be if not provided in the flexible circuit  74 . Therefore, in some embodiments, this configuration allows the flexible film  20 , the spacer layer  72 , and the flexible circuit  74  to be used in a key fob  10  without substantially modifying the PCB  14  previously used in the key fob  10 , and permits the number and locations of switches  60  to be changed from application to application without the expense of modifying the PCB  14 . 
     To assemble the key fob  10  illustrated in  FIGS. 20   a - b  and  21 - 23 , the flexible film  20 , the spacer layer  72 , and the flexible circuit  74  can be front loaded or assembled (i.e., installed from a front of the key fob  10 ) into the recess  95  of the upper housing  12   b.  In some embodiments, the flexible circuit  74  can be joined with the lower surface  96  of the recess  95  using adhesive bonding or by another suitable method. Therefore, once the flexible circuit  74  is installed, the spacer layer  72  can be joined to the flexible circuit  74  and the flexible film  20  can be joined to the spacer layer  72  using adhesive bonding or by another suitable method. In other embodiments, the flexible film  20 , the spacer layer  72 , and the flexible circuit  74  are joined before the components are installed in the recess  95 . For example, the flexible film  20 , the spacer layer  72 , and the flexible circuit  74  can be joined using a lamination process, by adhesive bonding, or using another suitable method. The resulting assembly can then be placed within the recess  95  and joined with the upper housing  12   b  (e.g., the lower surface  96 ) using adhesive bonding or by another suitable method. 
     Once the flexible film  20 , the spacer layer  72 , and the flexible circuit  74  are installed in the recess  95 , the one or more connectors  76  and the PCB  14  can be installed within the upper housing  12   b.  As described above, in some embodiments, the connector  76  can be self-adhesive, and can be actuated by pressure applied by the flexible circuit  74  and the PCB  14 . In some embodiments, the PCB  14  can also be joined to an interior surface of the lower surface  96  of the upper housing  12   b  using adhesive bonding or by another suitable method. The lower housing  12   a  can then be joined with the upper housing  12   b,  and the battery  26  and the battery access door  28  can be installed. In some embodiments, the lower housing  12   a  and the upper housing  12   b  can be joined using a snap or force fit, by adhesive, or using another suitable method. In some embodiments, if the lower housing  12   a  includes standoffs on an interior portion to provide supporting surfaces for the PCB  14 , the standoffs can be aligned with the PCB  14  when the lower housing  12   a  is installed. Adhesive bonding can also be used to join the PCB  14  with the standoffs. It should be understood that in addition to or in place of using adhesive bonding or other suitable methods, one or more of the components of the key fob  14  can be assembled using a force or pressure fit. For example, force provided by the lower housing  12   a  joined with the upper housing  12   b  can be applied to the internal components of the key fob  10  in order to hold all or a subset of the components in place. 
     It should also be noted that the interior components of  FIGS. 20   a - b  and  21 - 23  can also be used with other exterior configurations, such as the configurations described above with respect to  FIGS. 1 ,  4   b ,  8 ,  9 , and  11   a.  Similarly, the exterior components and configuration of  FIGS. 20   a - b  and  21 - 23  can be used with other interior configurations, such as the configurations described above with respect to  FIGS. 1-6 ,  7 ,  10 ,  11   b , and  12 . 
       FIGS. 24 and 25  are cross-sectional views of a key fob according to another embodiment of the present invention. In some embodiments, the exterior of the key fob  10  of  FIGS. 24 and 25  is similar to the exterior of the key fob  10  illustrated in  FIG. 20   a . It should be understood, however, that the interior components of the key fob  10  illustrated in  FIGS. 24 and 25  can be used with other exterior configurations, such as the configurations described above with respect to  FIGS. 1 ,  4   b ,  8 ,  9 , and  11   a.    
     As shown in  FIGS. 24 and 25 , the illustrated key fob  10  includes an upper housing  12   b  including a recess  95 , a lower surface  96 , and an opening  98 ; a flexible film  20 ; a spacer layer  72 ; a flexible circuit  74  including one or more switches  60 ; one or more connectors  76 ; a PCB  14 ; a lower housing  12   a;  a battery  26 ; and a removable battery access door  28 . As also shown in  FIGS. 24 and 25 , the illustrated flexible circuit  74  includes a trace tail  100 . The trace tail  100  can be constructed of flexible material (such as that of the flexible circuit  74 ) and can extend from an end of the flexible circuit  74  or from any other location on the flexible circuit  74 . The trace tail  100  includes all or a subset of the electrical traces of the flexible circuit  74  and the associated contact patches. 
     In some embodiments, the key fob  10  of  FIGS. 24 and 25  can be assembled as described above with respect to  FIGS. 20   a - b  and  21 - 23 . However, the trace tail  100  can be fed through the opening  98  of the upper housing  12   b,  and the contact patches on the trace tail  100  can be connected to the contact patches on the PCB  14  using one or more connectors  76 , as described above. By placing the contact patches of the flexible circuit  74  on the trace tail  100 , the flexible circuit  74  no longer needs to be rigidly joined to the PCB  14 . This feature can increase the speed and ease of installation, because the flexible circuit  74  no longer needs to be accurately aligned with the connector  76  and/or the PCB  14  to form a proper electrical connection. In addition, the flexible trace tail  100  can allow the PCB  14  to move with respect to the flexible circuit  74 . For example, if the key fob  10  is dropped, movement of the PCB  14  will generally not cause the PCB  14  to lose its electrical connection with the flexible circuit  74  because the flexible trace tail  100  will flex and move with the PCB  14 . In addition, in some embodiments, the PCB  14  can be held within the housing  12  of the key fob  10  with resilient or flexible elements, such as rubber feet. The resilient or flexible elements, combined with the flexible trace tail  100 , can further allow the PCB  14  to “float” or move within the key fob  10  in order to avoid shock or damage to the PCB  14  while still maintaining an electrical connection with the flexible circuit  74 . In some embodiments, the trace tail  100  also permits the use of a curved or bowed flexible circuit  74  (and associated spacer layer  72  and/or flexible film  20 ) to be joined to a relatively flat PCB  14 . 
     It should be understood that, in some embodiments, the flexible circuit  74  can include multiple trace tails  100 . For example, the flexible circuit  74  can include a trace tail  100  for each contact patch. In some embodiments, each trace tail  100  can have its own opening  98  in the upper housing  12   b.  In other embodiments, multiple trace tails  100  can use a common opening  98 . By providing a trace tail  100  for each contact patch, each contact patch can be connected to a contact patch on the PCB  14  where a corresponding switch  60  would be if not provided in the flexible circuit  74 . Therefore, in some embodiments, this configuration allows the flexible film  20 , the spacer layer  72 , and the flexible circuit  74  to be used in a key fob  10  without substantially modifying the PCB previously used in the design of the key fob  10 . 
       FIG. 26   a  is a perspective view of a key fob  10  according to another embodiment of the present invention. The illustrated key fob  10  includes a flexible film  20  including a plurality of contact surfaces  44  and a housing  12  consisting of a lower housing  12   a.  As shown in  FIG. 26   a , the flexible film  20  is thermoformed (as described above with respect to  FIG. 9 ) to define an upper portion of the key fob  10 . When thermoformed, the flexible film  20  can define one or more side surfaces  102  of the key fob  10  that join with the housing  12 . As shown in the cross-sectional views of  FIGS. 26   b  and  27 , the flexible film  20  can be thermoformed such that the shape of the flexible film  20  substantially matches the contour of an encapsulating material  104  defining an interior of the key fob  10 . Although the flexible film  20  can be thermoformed as just described, in other embodiments, other manners of forming the flexible film  20  are possible depending at least in part upon the material used for the flexible film. Such alternative manners of forming the flexible film  20  fall within the spirit and scope of the present invention. 
     As shown in  FIGS. 26   b  and  27 , an encapsulating material  104  can at least partially encase the spacer layer  72 , the flexible circuit  74 , the one or more connectors  76 , and the PCB  14  within the thermoformed flexible film  20 . In some embodiments, the encapsulating material  104  includes a resin, such as polyamide hot melt adhesive, that provides low-pressure molding. For example, the encapsulating material  104  can be passed under low pressure into a mold or form containing the fob components. Using low pressure encapsulation (as compared to higher-pressure encapsulation) can prevent the components of the key fob  10  from being damaged during the assembly process. 
     Once encapsulated, the encapsulating material  104  protects the components from dust, debris, moisture, and shock. For example, once encapsulated, the components cannot move even if the key fob  10  is dropped or strikes another surface. In addition, using the encapsulating material  104  to define an upper housing for the key fob  10  eliminates the need for a separate upper housing (such as an injection molded housing), which can have a higher tooling cost. Similarly, by forming an upper housing of the key fob  10  with the encapsulating material  104 , in some embodiments the flexible film  20  no longer needs to be adhesively bonded to an upper housing. In addition, the encapsulating material  104  can eliminate adhesive bonding for joining other components of the key fob  10  (e.g., the flexible circuit  74  and the PCB  14 ). 
     To assemble the key fob  10  of  FIGS. 26   a - b  and  27 , the spacer layer  72 , the flexible circuit  74 , the one or more connectors  76 , and the PCB  14  can be back loaded or assembled within the thermoformed flexible film  20  using adhesive bonding or another similar method. Once the components are assembled, the encapsulating material  104  can be injected or otherwise introduced around the components, such as within a mold or form. As shown in  FIG. 26   b , the encapsulating material  104  can fully encapsulate the components except for a connection point on the PCB  14  for the battery  26 . As also shown in  FIG. 26   b , the encapsulating material  104  can also form a joint  105  that interfaces with the lower housing  12   a.  For example, the lower housing  12   a  can be joined at the joint  105  to the encapsulating material  104  and/or the thermoformed flexible film  20  using adhesive bonding or by another suitable method. Once the lower housing  12   a  and the upper housing  12   b  are joined, the battery  26  and the battery access door  28  can be installed. As described above, in some embodiments, the key fob  10  of  FIGS. 26   a - b  and  27  can be assembled almost entirely in a single position (e.g., back loaded), meaning that the components do not need to be turned over until the end of the assembly, which can speed the process and lower costs. 
     In some embodiments, the encapsulating material  104  encases only a portion of an interior cavity of the key fob  10 . For example, as shown in  FIG. 26   b , the key fob  10  can include a space  106  between the encapsulating material  104  and a portion of the lower housing  12   a.  In other embodiments, the encapsulating material  104  can fill more of the interior cavity of the key fob  10 , or can fill all or substantially all of the interior cavity. For example, as shown in  FIGS. 28 and 29 , the encapsulating material  104  can substantially fill the interior cavity of the key fob  10 . Using this configuration, the encapsulating material  104  can bind the lower housing  12   a  to the thermoformed flexible film  20  without the need for adhesive bonding or another manner of attachment. 
     Similarly, in some embodiments, the encapsulating material  104  can itself form or define a lower housing for the key fob  10 . For example, as shown in  FIGS. 30 and 31 , the encapsulating material  104  can be molded to define the lower portion of the key fob  10 . As shown in  FIGS. 30 and 31 , the encapsulating material  104  can encase the spacer layer  72 , the flexible circuit  74 , the one or more connectors  76 , and the PCB  14  within the thermoformed flexible film  20 , and can provide an opening for a connection point on the PCB  14  for the battery  26  and the battery access door  28 . In some embodiments, the battery access door  28  can be installed and joined with the encapsulating material  104  using a force or snap fit. In other embodiments, the battery access door  38  can be installed and joined with the encapsulating material  104  using an adhesive or by another suitable method. Using the encapsulating material  104  to define the lower housing of the key fob  10  eliminates the need to provide a separate lower housing, such as an injection molded housing, and can thereby reduce manufacturing costs. Similarly, using the encapsulating material  104  to define the lower housing of the key fob  10  can eliminate the need to adhesively bond the flexible film  20  (and/or a separate upper housing) to a lower housing. 
     It should be understood that the encapsulating material  104  described above with respect to  FIGS. 26   a ,  26   b , and  27 - 31  can be used in other interior configurations of the key fob  10  described and/or illustrated herein. For example, the encapsulating material  104  can be used in various manners in the configurations described above with respect to  FIGS. 2 ,  4   a ,  4   b ,  5 ,  7 ,  11   b,    13 ,  18 ,  20   b,    22 , and  24 . In each of these configurations, the encapsulating material  104  can be used to adhere one or more components together and/or to encase one or more components to protect the components from dust, debris, moisture, and shock. 
     It should also be understood that the interior and exterior configurations described above with respect to  FIGS. 1-31  can be combined in various manners. Furthermore, the functionality provided by the components included in the key fob  10  can be combined and/or distributed among fewer or additional components. For example, in some embodiments, the functionality provided by the PCB  14  (e.g., an antenna, a controller or processor, etc.) can be provided by components included in the flexible circuit  74 . Similarly, in some embodiments, the functionality provided by the spacer layer  74  can be combined with the flexible film  20  and/or the flexible circuit  74  such that a separate spacer layer  74  is not needed. Furthermore, in some embodiments, the battery  26  can include a flexible battery (e.g., a “paper” battery) that can be joined to the PCB  14  or the flexible circuit  74  using adhesive bonding or by another suitable method. Using this configuration, if the battery  26  is exhausted, the battery  26  can be replaced or a portion of the key fob  10  can be replaced. For example, to replace the battery  26 , a new assembly can be installed including a new flexible film  20 , a new spacer layer  72 , a new flexible circuit  74 , and a new battery  26 . 
     Furthermore, in some embodiments, portions of the key fob  10  can be changed or replaced after assembly in order to provide customized features. For example, in some embodiments, the flexible film  20  can be removed and/or overlaid with a new flexible film  20  including customized colors, patterns, textures, and/or graphics (e.g., graphics associated with sports teams, universities, companies, designers, personal photographs, personal names, and the like). In other embodiments, the flexible film  20 , spacer layer  72 , and flexible circuit  74  can be removed and replaced with a new flexible film  20 , spacer layer  72 , and flexible circuit  74  to customize the colors and/or graphics, and/or to customize the number and/or locations of the contact surfaces  44  and associated switches on the key fob  10 . For example, if a user desires to add or remove a contact surface  44  and associated switch on the key fob  10 , the user can replace the flexible film  20 , spacer layer  72 , and flexible circuit  74  on the key fob  10  with a new flexible film  20 , a new spacer layer  72 , and a new flexible circuit  74  defining fewer or additional contact surfaces  44  and associated switches. 
     In some embodiments, an upper housing  12   b  and/or a lower housing  12   a  of the key fob  10  or a portion thereof can be removed to allow a user to replace the flexible film  20 , the spacer layer  72 , and/or the flexible circuit  74 . For example, in some embodiments, the upper housing  12   b  illustrated in  FIGS. 11   b  and  12  can be removed to replace the flexible film  20 , the spacer layer  72 , and/or the flexible circuit  74 . Similarly, the upper housing  12   b  illustrated in  FIGS. 20   b  and  21 , which includes a recess  95  that receives the flexible film  20 , spacer layer  72 , and flexible circuit  74 , can also include a substantially transparent cover or lid that can be pivoted or removed to replace the flexible film  20 , the spacer layer  72 , and/or the flexible circuit  74  contained within the recess  95 . In some embodiments, the one or more connectors  76  between the flexible circuit  74  and the PCB  14  can provide a force or snap fit and/or a reusable or replaceable adhesive to accommodate replacement of the flexible circuit  74 . Similarly, other components of the key fob  10  can also provide a force or snap fit and/or a reusable or replaceable adhesive to accommodate the replacement of components after assembly. 
     It should be understood that the key fobs  10  described and illustrated herein can be configured in various shapes and sizes and with various features. For example,  FIG. 32  is a perspective view of a key fob according to another embodiment of the present invention. As shown in  FIG. 32 , the flexible film  20  of the key fob can include a groove  114 . In some embodiments, the groove  114  provides a pseudo “part line” defining one or more sections of the flexible film  20 . For example, the groove  114  can define a first area for locking and unlocking vehicle doors and a second area for activating a vehicle alarm. Similarly, as shown in  FIG. 32 , the groove  114  can define a user interface surface  20   a  including one or more contact surfaces  44  and a side or edge surface  20   b.  In some embodiments, the sections defined by the groove  114  can include different colors, graphics, textures, and/or patterns to further differentiate the sections. For example, the key fob  10  of  FIG. 32  includes a first user interface surface with multiple contact surfaces  44  and includes a chrome-colored side surface  20   b.    
     As shown in  FIG. 32 , the key fob  10  can also include an opening  110  for receiving a key ring  112  or other device for hanging the key fob  10  and/or connecting the key fob  10  with other keys, key fobs, key rings, purses, wallets, and the like. In some embodiments, the opening  110  can be formed within the housing  12  of the key fob  10 , such as within a lower housing  12   a  and/or an upper housing  12   b.  In other embodiments, the opening  110  can be formed on a ridge  113  extending from the housing  12 . It should be understood that the opening  110  and key ring  112  can be at various locations on the key fob  10 . 
       FIGS. 33 and 34  are cross-sectional views of an upper assembly  116  of the key fob  10  of  FIG. 32 , taken along line  33 - 33  of  FIG. 32  according to an embodiment of the present invention. The upper assembly  116  can include an upper housing  12   b,  a flexible film  20 , a spacer layer  72 , a flexible circuit  74  with a trace tail  100 , a connector  76 , and a PCB  14 . In some embodiments, the flexible film  20  can be thermoformed to match the contour of the upper housing  12   b,  as described above with respect to  FIG. 9 . As shown in  FIG. 33 , the groove  114  is positioned over an open space  117  between an edge of the spacer layer  72  and the flexible circuit  74  and an interior edge of the upper housing  12   b.  The open space  117  can receive the groove  114  of the flexible film  20  in order to maintain a substantially continuous height of the flexible film  20 . 
     As shown in  FIGS. 33 and 34 , the upper housing  12   b  of the key fob  10  can include a recess  95  with a lower surface  96 . As described above with respect to  FIGS. 21-25 , the recess  95  and the lower surface  96  can receive and support the flexible film  20 , the spacer layer  72 , and the flexible circuit  74 . As shown in  FIG. 33 , the upper housing  12   b  can also include an opening  98  for receiving a trace tail  100  of the flexible circuit  74 . As described above with respect to  FIGS. 24-25 , one or more connectors  76  can be used to connect the trace tail  100  to the PCB  14 . It should be understood that other interior configurations described and/or illustrated herein can be used with the groove  114 . For example, the flexible film  20  with the groove  114  can be used with the configurations described above with respect to  FIGS. 2 ,  4   a ,  4   b ,  5 ,  7 ,  11   b ,  13 ,  18 ,  20   b ,  22 ,  24 ,  26   b ,  28 , and  30 . 
       FIG. 35  is a perspective view of an embodiment of the key fob  10 . The upper housing  12   b  of the key fob  10  can include one or more grooves  118 . One of the grooves  118  serves to receive an edge of a flexible film  20 . The groove  118  can also serve to as a psuedo “part line” defining one or more sections of the key fob  10 . The key fob  10  can also include one or more openings  110  for receiving a key ring  112  or other device for hanging the key fob  10  and/or connecting the key fob  10  with other keys, key fobs, key rings, purses, wallets, and the like. The flexible film  20  may include different colors, graphics, textures, and/or patterns to differentiate sections of the key fob  10 . 
       FIGS. 36 and 37  are cross-sectional views of the upper assembly  116  of the key fob  10  of  FIG. 35 , taken along line  36 - 36  of  FIG. 35  according to an embodiment of the present invention. The upper assembly  116  includes the upper housing  12   b,  the flexible film  20 , a switch matte  120 , the printed circuit board (PCB)  14 , and one or more switches  18 . The switch matte  120  includes one or more actuation fingers  122  and one or more support members  124 . In some embodiments, the flexible film  20  can be thermoformed to match the contour of the upper housing  12   b,  as described above with respect to  FIG. 9 . In some embodiments, an adhesive is applied to the portion of the switch matte  120  that is in contact with the upper housing  12   b.  In other embodiments, the switch matte  120  is manufactured to certain tolerances such that the switch matte  120  is fixed in place with regard to the upper housing  12   b  using a press fit. The flexible film  20  is placed over the switch matte  120  and a portion of the upper housing  12   b.  In one embodiment, a portion of the flexible film  20  is forced into the groove  118 . In some embodiments, an adhesive is applied to the flexible film  20  to fix the flexible film  20  to either the upper housing  12   b,  the switch matte  120 , or both. 
     As shown in  FIGS. 35-37 , the switch matte  120  transmits a user input to the PCB  14 . A user selects a portion of the flexible film  20  to press. In the disclosed embodiment, the flexible film  20  has graphics of various functions for an automobile such as locking doors, sounding the horn, and unlocking the doors. Each graphic is aligned with an actuation finger  122 . The user applies pressure to the graphic corresponding to a desired automobile function, the graphic appearing on a portion of the flexible film  20 . The pressure on the flexible film  20  forces the flexible film  20  to deform towards the PCB  14 . As the flexible film  20  deforms toward the PCB  14 , the flexible film  20  forces the actuation finger  122  to move toward the switch  18 . When the actuation finger  122  has moved a set amount, the switch  18  is triggered, which sends a signal to the PCB  14 , which then sends a signal to an automobile. In some embodiments, when the switch  18  is triggered an audible click is emitted. One embodiment includes a light source disposed on the PCB  14 , the light source being activated when the switch  18  is triggered, the light source being viewable by the user. In some embodiments the light source is viewable through at least one of the flexible film  20  and the switch matte  120 . In these embodiments, the switch matte  120  may be made of a material, such as polyethylene, which allows light to pass through. In addition to the embodiments illustrated in  FIGS. 35-37 , it is contemplated that the light source may be incorporated in any of the embodiments described herein. 
     As shown in  FIGS. 35-37 , the key fob  10  includes multiple graphics corresponding to various different automobile functions. The support means  124  and a support web  119  of the switch matte  120  ensure that multiple switches  18  are not triggered when the user presses on only one graphic. When the user applies pressure to a portion of the flexible film  20 , the entire flexible film  20  begins to deform. As the flexible film  20  deforms it begins to move the actuation finger  122  as described above, which also results in the support web  119  being moved and/or deformed. The support means  124  is substantially rigid, and is substantially fixed for movement relative to the upper housing  12   b.  Thus the support means  124  does not substantially move when the user applies pressure to a portion of the flexible film  20 . In some embodiments the support means  124  is in contact with the PCB  14 . 
       FIG. 38  shows an embodiment of the flexible film  20  of the key fob  10  illustrated in  FIG. 35 , including an exterior layer  126  of the flexible film  20  and an inner layer  128  of the flexible film  20 . The flexible film  20  of the key fob  10  illustrated in  FIG. 35  can be used with any of the key fobs described herein. For example, the flexible film  20  which includes an exterior layer  126  and an inner layer  128  can be used with the configurations described above with respect to  FIGS. 2 ,  4   a ,  4   b ,  5 ,  7 ,  11   b,    13 ,  18 ,  20   b,    22 ,  24 ,  26   b,    28 ,  30 , and  33  or with any of the configurations described below. The exterior layer  126  includes a front side  130  and a back side  132 . The inner layer  128  includes a front side  134  and a back side  136 . The exterior layer  126  and inner layer  128  may be formed with a die-cut as described herein or formed by using a thermal forming process as described herein. A matched metal tool may also be used to form the inner layer  128  and exterior layer  126 . Both the inner layer  128  and exterior layer  126  may be formed with various shapes, such as a groove or a raised surface. In one embodiment, both the inner layer  128  and exterior layer  126  are formed to substantially match a contour of a portion of the key fob  10 . The inner layer  128  is attached to the exterior layer  126  using a substantially transparent adhesive; the inner layer  128  and exterior layer  126  may also be pressed together or rolled together using rollers. In one embodiment, the inner layer  128  is attached to the exterior layer  126  using a thermoset bond. 
     Graphics, colors, patterns, textures and text may be printed on the front side  134  of the inner layer  128 . Screen printing can be used to provide high resolution printing in a single or multiple layers at a relatively low cost. Other embodiments can use other methods of customizing the flexible film  20 , such as laser printing, colored films, decals, and the like. The exterior layer  126  of the flexible film  20  is substantially transparent so that the printing on the front side  134  of the inner layer  128  may be seen when the inner layer  128  is attached to the exterior layer  126 . 
     The exterior layer  126  and inner layer  128  may be made of polycarbonate, polyester, a polyester-polycarbonate blend, or some other material with similar properties. It is not necessary that the exterior layer  126  and inner layer  128  be made of the same material. In one embodiment, the exterior layer  126  and inner layer  128  have approximately the same thickness. In another embodiment, the exterior layer  126  and inner layer  128  have different thicknesses. In one embodiment, the exterior layer has a thickness of approximately 0.13 mm. In yet another embodiment seen in  FIG. 38   a  only one layer of flexible film  20  is used, the flexible film  20  having a front side  131  and a back side  133 . 
       FIG. 39  is a perspective view of another embodiment of the key fob  10 . The embodiment illustrated in  FIG. 39  may share components with other illustrated embodiments. Therefore, like components are designated with like reference numerals and will not be described again in detail. The key fob  10  includes the elongated aperture  30  that can receive the mechanical key blade  34 .  FIG. 40  is an exploded cross-sectional view of the embodiment illustrated in  FIG. 39 . The key fob  10  includes the flexible film  20 , the upper housing  12   b,  an insert  150 , a spider  152 , the PCB  14 , and the lower housing  12   a.  The upper housing  12   b  includes an opening  151 . The PCB  14  can include one or more of the switches  18 . 
       FIG. 41  illustrates the insert  150 . The insert  150  is shaped and configured to be approximately the same size as the opening  151 . The insert  150  includes a plurality of apertures  153 . In one construction, the number of apertures  153  corresponds to the number of switches  18  on the PCB  14 . A support surface  155  surrounds each aperture  153 , the support surface  155  serving to inhibit the flexible film  20  when flexing more than a preset limit. Thus each support surface  155  has a size and shape determined to allow the flexible film  20  to flex a preset amount. The upper side of the insert  150  may include a plurality of ridges  154 , the ridges  154  to assist in providing the operator with a tactile sense of where each button lies. The lower side of the insert  150  includes a plurality of cutouts  156 , the cutouts  156  being included to ease the assembly of the key fob  10 . A plurality of extensions  158  (not shown) is molded to the lower side of the insert  150  to ease the assembly of the key fob  10 . Alternative embodiments include an insert  150  being larger or smaller than the opening  151 . 
       FIG. 42  illustrates the spider  152 . The spider  152  includes a plurality of plungers  160 . In one construction, the number of plungers  160  corresponds to the number of switches  18  on the PCB  14 . The spider  152  includes a plurality of legs  162  which couple the plungers  160  together. A plurality of holes  161  are molded in the spider  152 , the holes  161  corresponding to the extensions  158  of the insert  150 . The plurality of holes  161  and legs  162  are included to facilitate assembly of the key fob  10 . The spider  152  may be molded of a material that will not stress crack during flexure. 
       FIG. 43  illustrates the upper housing  12   b,  including the insert  150  and the spider  152 .  FIG. 44  is an alternative view of the upper housing  12   b,  including the insert  150  and the flexible film  20 . During assembly the spider  152  is assembled to the insert  150 , then the insert  150  and spider  152  are dropped into the upper housing  12   b.  The flexible film  20  is then secured to the upper housing  12   b  as has been described in other embodiments. The lower housing  12   a  may be attached to the upper housing  12   b  before or after the flexible film  20  is secured to the upper housing  12   b.  The lower housing  12   a  and upper housing  12   b  may be coupled together using a press fit, a snap fit, a screw, an adhesive, or some other means of holding the two pieces together. In addition to the assembly sequence described herein, other assembly sequences are contemplated. 
     In some embodiments the flexible film  20  may be made of polycarbonate. In other embodiments the flexible film  20  may be made of polyester, as polyester film is resilient and not prone to denting. The flexible film  20  may include various layers, as has been described herein. One construction of the flexible film  20  may include graphics showing various functions of the key fob  10 . In another construction, the flexible film  20  includes ridges  164  molded therein, the ridges  164  corresponding in shape and size to the ridges  154  of the insert  150 . 
     The key fob  10  is shown in cutaway view in  FIGS. 45 and 46 .  FIG. 45  shows the plunger  160  in a first position.  FIG. 46  shows the plunger  160  in a second position illustrating what occurs when an operator presses down on the flexible film  20  to actuate the switch  18 . The flexible film  20  deforms in a downward direction, towards the switch  18 , pressing the plunger  160  in the downward direction as well. As the plunger  160  moves in the downward direction, the switch  18  on the PCB  14  is pressed. When the switch  18  is pressed, a signal is sent from the key fob  10 . In an alternative embodiment, the spider  152  is not used and instead individual plungers  160  are individually disposed proximate to the insert  150 , thus allowing the plungers to float. 
     The embodiment illustrated in  FIGS. 39-46  includes several advantages. The insert  150  provides a gently contoured surface in each button area, improving the tactile feel for the operator. The insert  150  also provides a rigid support underneath the flexible film  20  which prevents the flexible film  20  from being over flexed. If the flexible film  20  is over flexed, permanent deformation of the flexible film  20  may occur. The insert  150  and spider  152  also provide for ease of assembly of the key fob  10 , as has been described. 
       FIGS. 47-48  illustrate an alternative construction that may be used with other embodiments heretofore described, in particular the embodiments illustrated in  FIGS. 35-46 . The switch matte  120  may be modified to include an aperture  170  therein. The switch matte  120  includes a connecting piece  172  which bridges across the aperture  170 . Coupled to the connecting piece  172  is a support  174 . A floating plunger  176  is disposed in the aperture  170 . The floating plunger  176  is able to move relative to the switch matte  120  between a first position when the switch  18  is not activated (see  FIG. 47 ) and a second position when the switch  18  is activated (see  FIG. 48 ). When the operator places pressure on the portion of the flexible film  20  corresponding to the location of the floating plunger  176 , as shown in  FIG. 48 , the flexible film  20  deforms moving the support  174 . As the support  174  moves, the floating plunger  176  moves, thus pressing the switch  18  to send a signal from the key fob  10 . The illustrated construction is advantageous because the possible deflection of the flexible film  20  is limited by the floating plunger  176 , thus inhibiting permanent denting of the flexible film  20 . 
       FIGS. 49-50  illustrate an alternative construction that may be used with other embodiments heretofore described, in particular the embodiments illustrated in  FIGS. 35-46 . The construction is similar to the construction illustrated in  FIGS. 47 and 48 , but it does not include a support  174 . In addition, the floating plunger  176  is longer, such that when the flexible film  20  is depressed the flexible film  20  contacts connecting piece  172  which contacts the floating plunger  176 . In the construction illustrated in  FIGS. 49-50  the portion of the floating plunger  176  which contacts the connecting piece  172  is convex in shape, however, other constructions contemplate having the portion of the floating plunger  176  which contacts the connecting piece  172  be concave in shape. When the operator places pressure on the portion of the flexible film  20  corresponding to the location of the floating plunger  176 , as shown in  FIG. 50 , the flexible film  20  deforms moving the connecting piece  172 . As the connecting piece  172  is moved the floating plunger  176  moves, thus pressing the switch  18  to send a signal from the key fob  10 . 
       FIGS. 51-52  illustrate yet another alternative construction that is similar to the construction illustrated in  FIGS. 49 and 50 . However, the switch matte  120  of the construction illustrated in  FIG. 51  includes the connecting piece  172  being disposed between the floating plunger  176  and the switch  18 . The illustrated construction includes the floating plunger  176  having an upper surface  180  which is concave in shape and is in contact with the contact surface  44  of the flexible film  20  when pressure is placed on the contact surface  44 , moving the floating plunger  176  to the second position. As can be seen in  FIG. 51 , the entirety of the concave portion  180  is not touching the contact surface  44  when pressure is not placed on the the contact surface  44 . When the operator places pressure on the contact surface  44 , as shown in  FIG. 52 , the flexible film  20  deforms moving the floating plunger  176 . As the floating plunger  176  is moved, the connecting piece  172  moves, thus pressing the switch  18  to send a signal from the key fob  10 . The floating plunger  176  and switch matte  120  serve together to fully support the flexible film  20  and to inhibit the flexible film  20  from being permanently dented or deformed when the floating plunger  176  is in the second position. Positioning the connecting piece  172  as described may be advantageous for ease of assembly of the key fob  10 . 
     Alternative constructions of the insert  150 , the spider  152  and the upper housing  12   b  are contemplated. For example, the insert  150  and spider  152  may be molded as one piece. In another example, the insert  150  and the upper housing  12   b  may be molded as one piece. In yet another example the insert  150 , the spider  152  and the upper housing  12   b  may all be molded as one piece. Of course, in any of these constructions the switch matte  120  may be used in place of the insert  150 , and/or the floating plunger  176  may be used in place of the spider  152 . These constructions may be used in the embodiments illustrated in  FIGS. 35-52 . 
     Alternative embodiments of the key fob  10  utilize the PCB  14  (illustrated in  FIG. 59 ) in a standard configuration having five switches  18  thereon. The PCB  14  may be purchased for a more economical price per unit, or manufactured more efficiently, if large quantities are purchased or manufactured. One embodiment illustrated in  FIGS. 53-55 , includes the PCB  14 , the flexible film  20  having five functions printed thereon, and the upper housing  12   b  having multiple holes  183 , the number of holes  183  corresponding to the number of functions printed on the flexible film  20 . Coupled to the upper housing  12   b  is a plurality of fingers  184 , one finger  184  being disposed in each hole  183 . Each finger  184  is attached to the upper housing  12   b  at only one point, so that the fingers  184  cantilever when a force is applied to the finger  184 . The key fob  10  is assembled such that each function printed on the flexible film  20  is aligned with a tip  188  of one of the fingers  184 , and the tip  188  of one of the fingers  184  is aligned with one of the switches  18  such that when the user presses on the function printed on the flexible film  20 , the corresponding switch  18  is activated. The key fob  10  also includes the lower housing  12   a,  the battery  26  and other components as have been described herein. 
     The PCB  14  in a standard configuration having five switches  18  thereon may also be used in an alternative embodiment of the key fob  10  wherein the flexible film  20  has only four functions printed thereon, as shown in  FIGS. 56-58 . The embodiment illustrated in  FIGS. 56-58  is largely identical to the embodiment illustrated in  FIGS. 53-55 , but the upper housing  12   b  includes only four holes  183  and four fingers  184 , and the flexible film  20  includes only four functions printed thereon. However, the PCB  14  (illustrated in  FIG. 59 ) does include five switches  18 . For purposes of aesthetics, auto manufacturers desire that the functions printed on the flexible film  20  are centered along an axis of the key fob  10 . Thus in the case of one printed function, the printed function and corresponding hole  183  are not aligned with any of the switches  18 . The finger  184  is still able to actuate the switch  18  by sizing and configuring the finger  184  so that the tip  188  is aligned with the switch  18 , as shown in  FIG. 58 . 
       FIG. 60  is a perspective view of another embodiment of the key fob  10 . The embodiment illustrated in  FIG. 60  may share components with other illustrated embodiments. Therefore, like components are designated with like reference numerals and will not be described again in detail. The key fob  10  includes the elongated aperture  30  that can receive the mechanical key blade  34 .  FIG. 61  is an exploded cross-sectional view of the embodiment illustrated in  FIG. 60 . The key fob  10  includes the flexible film  20 , the upper housing  12   b,  a spider  152 , the PCB  14 , and the lower housing  12   a.  The PCB  14  can include one or more of the switches  18 . 
       FIG. 62  illustrates the upper housing  12   b.  The upper housing  12   b  includes multiple apertures  153 . In one construction, the number of apertures  153  corresponds to the number of switches  18  on the PCB  14 . At least one support surface  155  surrounds each aperture  153 , the support surfaces  155  serving to inhibit the flexible film  20  from flexing more than a preset limit. Thus each support surface  155  has a size and shape determined to allow a portion of the flexible film  20  to flex a preset amount. The upper housing  12   b  may include a plurality of ridges  154 , the ridges  154  to assist in providing the operator with a tactile sense of where each button lies. 
       FIG. 63  illustrates the spider  152  and the upper housing  12   b,  the spider  152  being disposed in the upper housing  12   b.  The spider  152  includes multiple plungers  160 . In one construction, the number of plungers  160  corresponds to the number of switches  18  on the PCB  14 . The spider  152  includes a plurality of legs  162  which couple the plungers  160  together. In an alternative embodiment, the spider  152  is not used and instead individual plungers  160  are individually disposed proximate to the upper housing  12   b,  thus allowing the plungers to float. The spider  152  and plungers  160  may be molded of a material that will not stress crack during flexure. 
       FIG. 64  is an alternative view of the upper housing  12   b  and the flexible film  20 . During assembly the spider  152  is assembled to the upper housing  12   b.  The flexible film  20  is then secured to the upper housing  12   b  as has been described in other embodiments. The PCB may then be secured to one of the upper housing  12   b  and the lower housing  12   a.  The lower housing  12   a  may be attached to the upper housing  12   b  before or after the flexible film  20  is secured to the upper housing  12   b.  The lower housing  12   a  and upper housing  12   b  may be coupled together using a press fit, a snap fit, a screw, an adhesive, or some other means of holding the two pieces together. In addition to the assembly sequence described herein, other assembly sequences are contemplated. 
     In some embodiments the flexible film  20  may be made of polycarbonate. In other embodiments the flexible film  20  may be made of polyester, as polyester film is resilient and not prone to denting. The flexible film  20  may include various layers, as has been described herein. One construction of the flexible film  20  may include graphics showing various functions of the key fob  10 . In another construction, the flexible film  20  includes ridges  164  molded therein, the ridges  164  corresponding in shape and size to the ridges  154  of the upper housing  12   b.    
     The key fob  10  is shown in cutaway view in  FIG. 65 , with the plungers  160  being in a first position.  FIG. 66  shows one of the plungers  160  in a second position illustrating what occurs when an operator presses down on the flexible film  20  to actuate the switch  18 . As can be seen in  FIG. 65 , when the plungers are in the first position, the contact surfaces  44  of the flexible film  20  are substantially not in contact with the support surfaces  155 . However, as can be see in  FIG. 66 , when one of the plungers is in the second position the corresponding contact surface  44  being pressed by the operator is substantially entirely in contact with the corresponding support surface  155 . The support surface  155  thus serves to inhibit the flexible film  20  from deforming more than a preset amount. The support surfaces  155  are sized, shaped and configured to allow the flexible film  20  to deform that preset amount. In one embodiment the support surfaces  155  are concave in shape. 
     When the contact surface  44  is pressed, the flexible film  20  deforms in a downward direction, towards the switch  18 , pressing the plunger  160  in the downward direction as well. As the plunger  160  moves in the downward direction, the switch  18  on the PCB  14  is pressed. When the switch  18  is pressed, a signal is sent from the key fob  10 . 
     The embodiment illustrated in  FIGS. 60-66  includes several advantages. The upper housing  12   b  provides a gently contoured surface in each button area, improving the tactile feel for the operator. The upper housing  12   b  includes support surfaces  155  which prevent the flexible film  20  from being over flexed. If the flexible film  20  is over flexed, permanent deformation of the flexible film  20  may occur. The upper housing  12   b  and spider  152  also provide for ease of assembly of the key fob  10 , as has been described with regard to other embodiments. 
     Thus, some embodiments of the invention provide, among other things, a key fob that can be customized with various numbers and locations of contact surfaces and associated switches in various shapes, sizes, colors, patterns, textures, and other stylized graphics. Accordingly, a group of vehicles of different makes, models, and editions can generally use the same key fob components but have individually customized key fobs by printing different graphics, textures, etc. on the flexible film, providing different spacer layers, and/or providing different flexible circuits, which can provide a significant cost savings. 
     Although the various devices described and illustrated herein are key fobs, it will be appreciated that many of the features disclosed herein can be employed in other portable and non-portable devices and systems. In short, the features of the present invention can be utilized in any device and system having a user interface in which one or more switches can be actuated by a user to control the device or system (or a device or system connected thereto). Such devices or systems include, without limitation, phones, GPS systems, computers and computer peripheral devices, audio equipment, and the like. 
     Various features and advantages of the invention are set forth in the following claims.