Abstract:
A device can include a molded housing having at least a first surface, and configured to contain electronic components; a capacitance sense structure attached to the first surface; and a capacitance sensing circuit comprising at least one integrated circuit device electrically coupled to the capacitance sense structure.

Description:
PRIORITY CLAIMS 
       [0001]    This application is a continuation or U.S. patent application Ser. No. 13/340,349 filed on Dec. 29, 2011 the contents of which are incorporated by reference herein. 
     
    
     TECHNICAL FIELD 
       [0002]    The present disclosure relates generally to electronic devices input systems, and more particularly to capacitance sensing systems. 
       BACKGROUND 
       [0003]    Electronic devices and systems can include input devices having a generally flat surface to enable cursor type control inputs. In particular, laptop computers typically include a touchpad assembly positioned adjacent to a keyboard, which can operate as a substitute for a pointing device, such as a mouse. Touchpads can utilize capacitance or resistance sensing to sense user inputs. 
         [0004]      FIG. 26  is an exploded view of a conventional laptop computer  2600 . A conventional laptop computer  2600  can include a display  2605 , a top housing portion  2603  and a bottom housing portion (not shown). A top housing portion  2603  can include openings  2605  to accommodate a separate touchpad assembly  2601  in a palm rest area  2607 . 
         [0005]      FIG. 27  is an exploded view of another conventional laptop computer  2700 . Conventional laptop computer  2700  can include a palm rest assembly  2707  having a housing  2703  with a touchpad assembly  2701  connected thereto. Touchpad assembly  2701  can extend through openings formed in the housing  2703 . 
         [0006]    Conventionally, sensing electrodes of a touchpad assembly  2701  can be formed from traces on a printed circuit board (PCB) contained within a touchpad assembly. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0007]      FIG. 1  is a side cross sectional view of a capacitance sensing system according to an embodiment. 
           [0008]      FIG. 2  is a side cross sectional view of a capacitance sensing system according to another embodiment. 
           [0009]      FIG. 3  is a side cross sectional view of a capacitance sensing system according to a further embodiment. 
           [0010]      FIG. 4  is a side cross sectional view of a capacitance sensing system according to another embodiment. 
           [0011]      FIG. 5  is a side cross sectional view of a capacitance sensing system according to another embodiment. 
           [0012]      FIG. 6  is a side cross sectional view of a capacitance sensing system according to another embodiment. 
           [0013]      FIG. 7  is a diagram showing a method of making a capacitance sensing system by ink jet printing according to an embodiment. 
           [0014]      FIGS. 8A to 8C  are a series of side cross sectional views showing a method of capacitance sensing system by screen printing according to an embodiment. 
           [0015]      FIGS. 9A to 9D  are a series of side cross sectional views showing a method of making a capacitance sensing system by pad printing according to an embodiment. 
           [0016]      FIGS. 10A and 10B  are side cross sectional views showing a method of making a capacitance sensing system with a subtractive process according to an embodiment. 
           [0017]      FIGS. 11A and 11B  are side cross sectional views showing a method of making a capacitance sensing system with a pre-formed conductive pattern according to an embodiment. 
           [0018]      FIGS. 12A to 12C  are a series of side cross sectional views showing a method of making a capacitance sensing system with a pre-formed conductive pattern according to a further embodiment. 
           [0019]      FIGS. 13A and 13B  are side cross sectional views showing a method of making a capacitance sensing system with a pre-formed conductive pattern according to another embodiment. 
           [0020]      FIGS. 14A and 14B  are side cross sectional views showing a method of making a capacitance sensing system with a pre-formed conductive pattern according to another embodiment. 
           [0021]      FIG. 15  is a top plan view of a single layer conductive pattern that can be included in embodiments. 
           [0022]      FIG. 16  is a top plan view of a further single layer conductive pattern that can be included in embodiments. 
           [0023]      FIG. 17  is a top plan view of another single layer conductive pattern that can be included in embodiments. 
           [0024]      FIGS. 18A to 18D  are a series of side cross sectional views showing a method of making a capacitance sensing system with multiple conductive patterns according to embodiments. 
           [0025]      FIGS. 19A to 19C  are top plan views showing a method of making a capacitance sensing system with multiple conductive patterns according to an embodiment. 
           [0026]      FIGS. 20A and 20B  are top plan views of a multiple layer conductive pattern that can be included in embodiments. 
           [0027]      FIGS. 21A and 21B  are top plan views of a further multiple layer conductive pattern that can be included in embodiments. 
           [0028]      FIGS. 22A and 22B  are top plan views of another multiple layer conductive pattern that can be included in embodiments. 
           [0029]      FIGS. 23A to 23C  are diagrams showing a connection between a conductive pattern and capacitance sensing circuits according to an embodiment. 
           [0030]      FIGS. 24A to 24D  are diagrams showing connections between a conductive pattern and capacitance sensing circuits according to various other embodiments. 
           [0031]      FIGS. 25A to 25I  are diagrams of electronic systems according to various embodiments. 
           [0032]      FIG. 26  is an exploded view of a conventional laptop computer having a touch pad. 
           [0033]      FIG. 27  is an exploded view of another conventional laptop computer having a touch pad. 
       
    
    
     DETAILED DESCRIPTION 
       [0034]    Various embodiments will now be described that include capacitance sensing structures and methods that can enable a capacitance sensing area to be formed on a surface of the housing (or some other assembly surface) of an electronic device. 
         [0035]    In the various embodiments shown below, like items are referred to by the same reference character. 
         [0036]    Referring now to  FIG. 1 , a capacitance sensing system  100  according to an embodiment is shown in a side cross sectional view. A capacitance sensing system  100  can include a housing  102 , a conductive pattern  108 , and circuit connections  110  to the conductive pattern  108 . A housing  102  can be a structure for containing components of an electronic or electrical device. In some embodiments, a housing  102  can be a molded or stamped structure. In one particular embodiment, a housing  102  can be a molded plastic structure. A housing  102  can have a first surface  104  and an opposing second surface  106 . In one very particular embodiment, a first surface  104  can be an internal surface of a housing  102 , while a second surface  106  can be an external surface of a housing  102 . 
         [0037]    A conductive pattern  108  can be formed on a first surface  104 . A conductive pattern  108  can generate variations in capacitance in response to the proximity of an object. This is in contrast to conventional approaches like those shown in  FIGS. 26 and 27 , in which sensing structures are circuit board traces (i.e., components protected by a housing). In the embodiment of  FIG. 1 , a conductive pattern  108  can be attached to a first surface by an intervening layer  114 . In one very particular embodiment, an intervening layer can be an adhesive for mechanically attaching conductive pattern  108  to first surface  104 . 
         [0038]    A circuit connection  110  can provide a conductive connection to capacitance sensing circuits. In some embodiments, a circuit connection  110  can extend vertically from a first surface  104 . 
         [0039]    In one embodiment, a second surface  106  can be an input surface of an electronic device  100 , with conductive pattern  108  sensing capacitance changes arising from objects proximate to, or contacting, the second surface  106 . In a very particular embodiment, a second surface  106  can be a touch surface for detecting finger (or other object) touch positions. 
         [0040]    Referring to  FIG. 2 , a capacitance sensing system  200  according to another embodiment is shown in a side cross sectional view.  FIG. 2  differs from  FIG. 1  in that a conductive pattern  108  can be formed directly on a first surface  104 . That is, there is no intervening layer ( 114  in  FIG. 1 ). 
         [0041]    Referring to  FIG. 3 , a capacitance sensing system  300  according to another embodiment is shown in a side cross sectional view.  FIG. 3  differs from  FIG. 1  in that a conductive pattern  108  can be inset into a first surface  104 . Accordingly, a first surface  104  can include insets  316  that receive and/or retain conductive pattern  108 . 
         [0042]    Referring to  FIG. 4 , a capacitance sensing system  400  according to a further embodiment is shown in a side cross sectional view.  FIG. 4  differs from  FIG. 1  in that a conductive pattern  108  can be formed within a housing  102 , and hence have little or no surfaces exposed. In such an embodiment, circuit connections  410  can include portions that extend into housing  102  to contact conductive pattern  108 . In addition or alternatively, conductive pattern  108  can include portions (not shown) that extend to first surface  104 . 
         [0043]    Referring to  FIG. 5 , a capacitance sensing system  500  according to yet another embodiment is shown in a side cross sectional view.  FIG. 5  differs from  FIG. 1  in that a housing  502  can include a first housing portion  502 - 0  that is thicker than a second housing portion  502 - 1 . A conductive pattern  108  can be formed on a surface  104  of the second housing portion  502 - 1 . 
         [0044]    Referring to  FIG. 6 , a capacitance sensing system  600  according to another embodiment is shown in a side cross sectional view.  FIG. 6  differs from  FIG. 1  in that a second surface  106  can include user indications  618  formed thereon. User indications  618  can identify locations where capacitance sensing can occur, including a type of input and/or an area of input. User indications  618  can include any suitable indication type, including but not limited to: symbols or lines formed with paint, ink, surface etching, or decals; variations in surface texture, surface color, surface material; or an illuminated area, to name just a few examples. 
         [0045]    It is noted that while  FIGS. 1 to 6  have shown systems with a single conductive pattern, such systems can include additional conductive patterns formed over the one conductive pattern shown. Particular embodiments having multiple conductive patterns are shown in more detail below. 
         [0046]    Having described various capacitance sensing system according to embodiments, methods of making such systems will now be described. 
         [0047]      FIG. 7  shows an inkjet printing method according to an embodiment. An inkjet printer can include an inkjet nozzle  712  that prints a conductive ink (or paint)  722  onto a first surface  104  of a housing  102 . Such a process can be an additive process as the conductive ink  722  can be printed in the desired conductive pattern shape. A conductive ink  722  can be any conductive ink suitable for providing the conductivity necessary for a desired capacitance sensing method. A conductive ink  722  can be a silver and/or carbon ink, as but two examples. 
         [0048]      FIGS. 8A to 8C  show a screen printing method according to an embodiment. 
         [0049]    Referring to  FIG. 8A , a screen  820  can be placed over a first surface  104  of a housing  102 . A conductive ink (or paint)  722  can be placed over screen  722 . 
         [0050]      FIG. 8B  shows the removal of excess conductive ink  722 , which can leave conductive pattern  108  within openings of screen  820 . 
         [0051]      FIG. 8C  shows the removal of the screen  820 , leaving the conductive pattern  108  on first surface  104 . 
         [0052]      FIGS. 9A to 9D  show a pad printing method according to an embodiment. 
         [0053]    Referring to  FIG. 9A , a pattern etching  928  can have etch openings  928  in the shape of a desired conductive pattern. Etch openings  928  can be initially filled with conductive ink (or paint)  722 . A pad  926  can contact etch openings  928  to attract conductive ink  722  in the shape of the desired conductive pattern. 
         [0054]      FIG. 9B  shows the pad  926  being positioned over first surface  104  of housing  102 .  FIG. 9C  shows pad  926  bringing conductive ink  722  into contact with first surface  104 . 
         [0055]    Referring to  FIG. 9D , a pad  926  can be lifted from first surface  104 , leaving a conductive pattern  108  on first surface  104 . 
         [0056]    While additive processes can be used to form a conductive pattern, in other embodiments, subtractive processes can be used. In a subtractive process, a conductive layer can be formed on a first surface. Subsequently, portions of the conductive layer can be removed to form the desired conductive pattern. 
         [0057]      FIGS. 10A and 10B  show one example of a subtractive process for forming a conductive pattern  108 . Referring to  FIG. 10A , a conductive layer  1032  can be formed over a first surface  104  (in this embodiment, directly on first surface  104 ). An etch mask  1030  can be formed on conductive layer  1032  having the shape of a desired conductive pattern. A conductive layer  1032  can be formed with any suitable method, including deposition, plating, or mechanical attachment, as but a few examples. 
         [0058]    Referring to  FIG. 10B , portions of conductive layer  1032  not covered by etch mask  1030  can be removed. Such etching can include wet chemical etching or plasma etching as but two examples. 
         [0059]    It is noted that a subtractive process does not require an etch mask. For example, in other embodiments, different removal techniques can be used to create a conductive pattern. As but a few examples, portions of a conductive layer can be removed by laser removal or mechanical methods, such as cutting or scraping. 
         [0060]    While some embodiments can pattern a conductive layer while it is over a first surface, other embodiments can utilize pre-fabricated conductive patterns. Examples of such embodiments will now be described. 
         [0061]      FIGS. 11A and 11B  show a method of forming a capacitance sensing system with a pre-fabricated conductive pattern. 
         [0062]    Referring to  FIG. 11A , a pre-formed conductive pattern  108  can be attached to a carrier  1136  on one side, and can have an adhesive  1134  formed on an opposing side. A pre-formed conductive pattern  108  can be formed according to any suitable method, including, but not limited to: cutting, etching, stamping, or printing. 
         [0063]    Referring to  FIG. 11B , adhesive  1134  on conductive pattern  108  can be brought into contact with first surface  104  of housing  102 . A carrier  1136  can then be removed, leaving a conductive pattern  108  on the first surface  104 . 
         [0064]      FIGS. 12A to 12C  show another embodiment in which a conductive pattern can be physically embedded into a housing surface. Referring to  FIG. 12A , a pattern frame  1240  can be positioned between a housing  102  and a stamp  1238 . A frame  1240  can include a desired conductive pattern, and may further include members  1242  that enable the frame  1240  to be physically positioned between stamp  1238  and housing  102 . In particular embodiments, a stamp  1238 , frame  1240  and/or housing  102  can be heated, to soften a first surface  104 . 
         [0065]    Referring to  FIG. 12B , a stamp  1238  can force frame  1240  into a first surface  104 . As shown in  FIG. 12C , a stamp  1238  can be withdrawn, and members  1242  trimmed, resulting in a conductive pattern  108  formed in the first surface  104 . 
         [0066]      FIGS. 13A and 13B  show an embodiment in which a conductive pattern can be physically embedded within a wall of a housing. Referring to  FIG. 13A , a pattern frame  1240  can be positioned within an opening of a mold  1344 . A material can then be injected into the mold  1344  to form a wall of a housing. Referring to  FIG. 13B , after the material has cured, it can be removed from mold  1344 . A resulting structure can have a conductive pattern  108  formed within a housing  102 , between first and second surfaces ( 104  and  106 ). 
         [0067]      FIGS. 14A and 14B  show an embodiment in which a conductive pattern can be mechanically attached to a surface of a housing. Referring to  FIG. 14A , mechanical members  1446  can be included for a housing  102 . A prefabricated conductive pattern  108  can be mechanically attached to first surface  104  with such mechanical members. It is noted that while  FIGS. 14A and 14B  show mechanical members formed as part of a housing, other embodiments can include alternate mechanical members, including but not limited to: screws, clips, rivets, pegs, bosses, etc. 
         [0068]    Conductive patterns according to embodiments herein can take various shapes. Particular embodiments single layer conductive patterns that can be included in embodiments will now be described. 
         [0069]      FIG. 15  shows a conductive pattern  1508  according to one embodiment. A conductive pattern  1508  can be formed on a housing surface  104  with one conductive layer. Conductive pattern  1508  can include a number of first electrodes  1558 - 0  to - 2 , having a same shape repeated in one direction. A second electrode  1560  can be interleaved with first electrodes ( 1558 - 0  to - 2 ). 
         [0070]      FIG. 16  shows another conductive pattern  1608  according to an embodiment. A conductive pattern  1608  can be formed on a housing surface  104  with one conductive layer. As in the case of  FIG. 15 , conductive pattern  1608  can include a number of first electrodes  1658 - 0  to - 2 , having a same shape repeated in one direction that are interleaved (in a spiral-like manner) with a second electrode  1660 . 
         [0071]      FIG. 17  shows another conductive pattern  1708  according to an embodiment. A conductive pattern  1708  can be formed on a housing surface  104  with one conductive layer. Conductive pattern  1708  can include first electrodes (one shown as  1758 - 0 ) repeated in one direction. In addition, second electrodes (one shown as  1760 - 0 ) can be repeated in the same direction. 
         [0072]    It is understood that any of the conductive patterns shown in  FIGS. 15-17  can be repeated in vertical and/or horizontal directions to cover a desired surface area. Further, while such embodiments can be formed with one conductive layer, in other embodiments, such patterns can be formed with more than one conductive layer. In addition, the conductive patterns of  FIGS. 15-17  are intended to be but three examples of numerous conductive patterns that can be employed in capacitance sensing systems described herein. 
         [0073]    As noted above, embodiments can include multiple conductive patterns formed over one another. Embodiments showing the formation of such structures will now be described. 
         [0074]      FIGS. 18A to 18D  show a method forming a multi-layered capacitance sense structure according to embodiments. 
         [0075]    Referring to  FIG. 18A , a first conductive pattern  108  can be formed on a first surface of a housing  102  according to any of the embodiment shown herein, or equivalents. 
         [0076]    Referring to  FIG. 18B-0 , an insulating layer  1862  can be formed over first conductive pattern  108 . An insulating layer  1862  can be deposited or applied. An insulating layer  1862  can include any suitable material, including but not limited to, an insulating ink, paint, or other coating. 
         [0077]    Referring to  FIG. 18C , a second conductive pattern  1864  can be formed on an insulating layer  1862 . A second conductive pattern  1864  can be formed using any of suitable technique described herein, or an equivalent. 
         [0078]      FIGS. 18B-1  shows an alternate method to that shown in FIGS.  18 B- 0 / 18 C. 
         [0079]    Referring to  FIG. 18B-1 , an electrode structure  1866  can include an insulating layer  1862  attached to a pre-formed second conductive pattern  1864 . In one particular embodiment, insulating layer  1862  can be, or can include, an adhesive material. Electrode structure  1866  can be brought into contact with a first surface  104  and first conductive pattern  108  to arrive at a structure like that of  FIG. 18C . 
         [0080]    The embodiments of  FIGS. 18A to 18C  show an arrangement in which an insulating layer  1862  and second conductive pattern  1864  can conform to a shape of a first conductive pattern  108 . However, as shown in  FIG. 18D , in other embodiments an insulating layer  1862 ′ may not be conformal, providing a substantially planar surface for second conductive pattern  1864 . 
         [0081]      FIGS. 19A to 19C  are a series of top plan views showing a method of making a capacitance sensing system according to a particular embodiment. Referring to  FIG. 19A , an electrode area  1970  can be defined on a first surface  104  of a housing. An electrode area  1970  can be an area where capacitance sensors are to be placed. In some embodiments, a region opposite to electrode area  1970  (i.e., a region on a surface opposite to  104 ) can be a user input surface. 
         [0082]    Referring to  FIG. 19B , a first conductive pattern  1908  can be formed on a first surface  104  as described herein, or equivalents. In the embodiment shown, a first conductive pattern  1908  can include first electrodes (one shown as  1958 ) and first circuit connection portions  1968 . First electrodes (e.g.,  1958 ) can be repeated in a first direction (shown as “y”). 
         [0083]    Referring to  FIG. 19C , an insulating layer (not shown) can be formed over a first conductive pattern  1908 . A second conductive pattern  1964  can be then be formed as described herein, or equivalents. In the embodiment shown, a second conductive pattern  1946  can include second electrodes (one shown as  1960 ) and second circuit connection portions  1968 ′. Second electrodes (e.g.,  1960 ) can be repeated in a second direction (shown as “x”). 
         [0084]    It is noted that while an insulating layer can be formed between first and second conductive patterns ( 1902  and  1964 ), such an insulating layer may not be formed over circuit connection portions  1968  (or can be subsequently removed from such portions) to ensure capacitance sensing circuits can have an electrical connection to the first conductive pattern  1908 . 
         [0085]    First and second circuit connection portions ( 1968  and  1968 ′) can provide connections to a capacitance sensing circuit. 
         [0086]      FIGS. 20A and 20B  are top plan views showing a method of making a capacitance sensing system according to another embodiment. Referring to  FIG. 20A , a first conductive pattern  2008  can be formed on first surface  104  as described herein, or equivalents. In the embodiment shown, a first conductive pattern  2008  can include first electrodes  2058 - 0  to - 2  that repeat in a first direction. First electrodes ( 2058 - 0  to - 2 ) can have a relatively large width (such a width being determined in the vertical direction in  FIG. 20A ). 
         [0087]    Referring to  FIG. 20B , following the formation of an insulating layer (not shown), a second conductive pattern  2064  can be formed as described herein, or equivalents. In the embodiment shown, a second conductive pattern  2064  can include second electrodes  2060 - 0  to - 2  that repeat in a second direction. Second electrodes ( 2060 - 0  to - 2 ) can have a relatively narrow width (such a width being determined in the horizontal direction in  FIG. 20B ), as compared to the first electrodes ( 2058 - 0  to - 2 ). 
         [0088]      FIGS. 21A and 21B  are top plan views showing a method of making a capacitance sensing system according to another embodiment. Referring to  FIG. 21A , a first conductive pattern  2108  can be formed on first surface  104  as described herein, or equivalents. In the embodiment shown, a first conductive pattern  2108  can include first electrodes  2158 - 0  to - 3  that repeat in a first direction. First electrodes ( 2158 - 0  to - 3 ) can have a repeating diamond pattern. 
         [0089]    Referring to  FIG. 21B , following the formation of an insulating layer, a second conductive pattern  2164  can be then be formed as described herein, or equivalents. In the embodiment shown, a second conductive pattern  2146  can include second electrodes  2160 - 0  to - 3  that repeat in a second direction. Second electrodes ( 2160 - 0  to - 3 ) can have a repeating diamond pattern that crosses over first electrodes ( 2158 - 0  to - 3 ) of first conductive pattern  2108 . 
         [0090]      FIGS. 22A and 22B  show an alternate diamond pattern capacitance sensing structure that can be included in the embodiments. Referring to  FIG. 22A , a first conductive pattern  2208  can include first electrodes  2158  like those labeled as  2158 - 0  to - 3  in  FIG. 21A . However, first conductive pattern  2208  can also include separated electrodes  2258  which can have a diamond shape, but be isolated from any other electrodes. Separated electrodes  2258  can have edge regions  2257  adjacent to narrow portions of first electrodes  2158 . 
         [0091]    Referring to  FIG. 22B , following the formation of an insulating layer (not shown) having openings that expose edge regions  2257 , a second conductive pattern  2264  can be formed. Second conductive pattern  2264  can include overpass electrode structures  2270  that join separated electrodes  2258  in a direction perpendicular to first electrodes  2158 . 
         [0092]    It is understood that any of the conductive patterns shown in  FIGS. 19A-22B  can be repeated in both vertical and horizontal direction to cover a desired surface area. Further, while such embodiments can be formed with two conductive layers, in other embodiments, such patterns can be formed with more than two conductive layers. In addition, the multi-layer conductive patterns of  FIGS. 19A-22B  are intended to be but examples of numerous conductive patterns that can be employed in capacitance sensing systems described herein. 
         [0093]    It is understood that once a last conductive pattern has been formed, a protective coating can be formed over the capacitance sensing structure, to protect it during subsequent manufacturing steps (e.g., transportation, assembly into a device, etc.). 
         [0094]    As noted above, conductive patterns formed on a housing surface, as described herein, can include portions that enable connections to capacitance sensing circuits. Embodiments showing connections to capacitance sensing circuits will now be described. 
         [0095]      FIG. 23A  shows a portion of a housing  102  having connection portions  2368  of a conductive pattern formed on a first surface  104 . It is understood that connection portions  2368  are but a small portion of one or more larger conductive patterns (see, for example,  FIG. 19C , which shows connection portions  1968 / 1968 ′). Optionally, a housing  102  can include mechanical connector structures (one shown as  2372 ). 
         [0096]      FIG. 23B  shows a printed circuit board (PCB)  2374  having connection traces  2375  formed thereon. Connection traces  2375  can provide a conductive path to one or more integrated circuit (IC) devices containing capacitance sensing circuits. In one embodiment, such IC device(s) can be mounted on the PCB  2374  on side opposite to that shown in  FIG. 23B . 
         [0097]    PCB  2374  is in sharp contrast to conventional approaches like that of  FIGS. 26 and 27 . PCB  2374  does not include traces that serve as capacitance sensors, and so is significantly smaller than a circuit board utilized in a conventional approach. As in the case of  FIG. 23A , optionally, a PCB  2374  can include mechanical connector structures (one shown as  2376 ). 
         [0098]      FIG. 23C  shows PCB  2374  mounted to housing  102  by vertical conductors  2380 . Vertical conductors  2380  can provide a conductive path between connection traces  2375  (of the PCB  2374 ) and connection portions  2368  (of a conductive pattern for capacitance sensing). In one embodiment, vertical conductors  2380  can be formed from a conductive adhesive, and thus provide both mechanical attachment and electrical connection to connection portions  2368 . In one very particular embodiment, vertical connectors  2380  can be formed from an anisotropic conductive adhesive (ACA). As noted above, an IC device  2351  containing capacitance sensing circuits can be attached to PCB  2374 . 
         [0099]    In some embodiments vertical conductors  2380  can provide the mechanical attachment between connection portions  2368  and connection traces  2370 . However, as noted above, in alternate embodiments, additional mechanical connections can be made between PCB  2374  and housing  102  by way of mechanical connector structures (e.g.,  2372 ,  2374 ). Such mechanical connector structures (e.g.,  2372 ,  2374 ) can secure PCB  2374  to housing  102  and help ensure that connection portions  2368  remain aligned with connection traces  2370 . Mechanical connector structures (e.g.,  2372 ,  2374 ) can take any suitable form, including but not limited to, screws, threaded inserts, plastic pegs, or bosses. 
         [0100]    While  FIGS. 23A to 23C  show embodiments that can include vertical conductors formed with a conductive adhesive, alternate embodiments can include conductive elastomeric connectors. In such embodiments, a spacer can be included to align the elastomeric connector with respect to a conductive pattern and corresponding circuit board traces. Such an embodiment is shown in  FIGS. 24A and 24B . 
         [0101]      FIG. 24A  shows a spacer  2486  having openings  2482  formed therein. A spacer  2486  can include a mechanical connector structures (one shown  2484 ). 
         [0102]      FIG. 24B  shows PCB  2374  mounted to housing  102  by elastomeric vertical conductors  2380 ′. Spacer  2486  can be situated between PCB  2374  and housing  102 . Openings  2482  within spacer  2486  can ensure vertical connectors  2380 ′ are properly aligned between connection portions  2368  and circuit traces of a PCB  2374 . Elastomeric vertical conductors  2380 ′ can require pressure in order to provide good electrical contact, accordingly, mechanical connector structures (e.g.,  2372 ,  2374 ,  2484 ) can be used to ensure such pressure exists. As noted above, mechanical connector structures (e.g.,  2372 ,  2374 ,  2484 ) can take any suitable form, including but not limited to, screws, threaded inserts, plastic pegs, or bosses. 
         [0103]    It is understood that after a PCB has been mounted to a housing, the resulting assembly could be covered with a protective coating. 
         [0104]    While embodiments above have shown capacitance sensing systems in which capacitance sensing circuits can be mounted in a PCB, in alternate embodiments, such circuits can be directly mounted on a conductive pattern formed on a housing surface. 
         [0105]    Referring to  FIG. 24C , a connection portion  2368  of a conductive pattern can be formed by plating with a suitable material, such as copper and/or gold. An integrated circuit  2351  in die form can be bonded to such connection portions. Integrated circuit  2351  includes capacitance sensing circuits. 
         [0106]    Referring to  FIG. 24D , alternatively, an integrated circuit  2351  in packaged form could have its physical connectors (e.g., leads, pins, landings, etc.) attached to the connection portions  2368  of the conductive pattern(s). Integrated circuit  2351  includes capacitance sensing circuits. 
         [0107]    While embodiments can include capacitance sensing systems formed on, or within, a housing wall of an electronic device, other embodiments can include electronic devices employing such systems. Such embodiments will now be described. 
         [0108]    Referring to  FIG. 25A , an electronic system according to an embodiment can include a laptop computer  2590 -A having a palm rest area  2592  next to a keyboard  2591 . All or a portion of palm rest area  2592  can form a housing portion of a capacitance sensing system  2500  as described herein, or equivalents. 
         [0109]    Referring to  FIG. 25B , an electronic system according to another embodiment can include a cell phone or similar device  2590 -B having a touch screen display  2593 . All or a portion of the region peripheral to the display  2593  can form a housing portion of a capacitance sensing system  2500  as described herein, or equivalents. 
         [0110]    Referring to  FIG. 25C , an electronic system according to another embodiment can include a telephone system  2590 -C. All or a portion of the housing for the device can form a housing portion of a capacitance sensing system  2500  as described herein, or equivalents. 
         [0111]    Referring to  FIG. 25D , an electronic system according to another embodiment can include a tablet computing device  2590 -D. A tablet computing device  2590 -D can include a touch screen display  2593 . As in the case of  FIG. 25B , all or a portion of the peripheral region can form a housing portion of a capacitance sensing system  2500  as described herein, or equivalents. 
         [0112]    Referring to  FIG. 25E , an electronic system according to another embodiment can include a human interface device (HID)  2590 -E, which in the embodiment shown, can be a computer mouse. All or a portion of HID housing can be a housing portion of a capacitance sensing system  2500  as described herein, or equivalents. In some embodiments, a HID  2590 -E can have one contiguous surface, dispensing with the need for mechanical buttons and/or wheels. 
         [0113]    Referring to  FIG. 25F , an electronic system according to another embodiment can include a computer keyboard  2590 -F. All or a portion of a surface of the keyboard can be a housing portion of a capacitance sensing system  2500  as described herein, or equivalents. In some embodiments, keyboard  2590 -F can have one contiguous surface, dispensing with mechanical buttons. 
         [0114]    Referring to  FIG. 25G , an electronic system according to another embodiment can include a gaming controller  2590 -G. All or a portion of a surface of the controller  2590 -G can be a housing portion of a capacitance sensing system  2500  as described herein, or equivalents. 
         [0115]    Referring to  FIG. 25H , an electronic system according to another embodiment can include a remote control device  2590 -H. All or a portion of a surface of the remote control can be a housing portion of a capacitance sensing system  2500  as described herein, or equivalents. 
         [0116]    Referring to  FIG. 251 , an electronic system according to another embodiment can include a light switch assembly  2590 -I. All or a portion of a face plate for can be a housing portion of a capacitance sensing system  2500  as described herein, or equivalents. 
         [0117]    Embodiments described herein can provide for more compact (e.g., thinner) devices, and thus improvements in aesthetics of a device. Large circuit board based assemblies, such as those utilized in conventional devices, can be replaced by electrodes formed on a housing surface, reducing the space needed for electronics. 
         [0118]    Embodiments described herein can provide for greater functionality than conventional approaches. Touch areas can be programmable, in both size and function. For example, in one configuration, a housing surface may function in a touchpad fashion. However, in an alternate configuration, the same housing surface may serve as multiple input buttons. In addition or alternatively, embodiments can provide larger area touch surfaces, not being limited to an assembly size, but rather the size and configuration of a housing surface. 
         [0119]    It should be appreciated that in the foregoing description of exemplary embodiments, various features are sometimes grouped together in a single embodiment, figure, or description thereof for the purpose of streamlining the disclosure aiding in the understanding of one or more of the various inventive aspects. This method of disclosure, however, is not to be interpreted as reflecting an intention that the claimed invention requires more features than are expressly recited in each claim. Rather, as the following claims reflect, inventive aspects lie in less than all features of a single foregoing disclosed embodiment. Thus, the claims following the detailed description are hereby expressly incorporated into this detailed description, with each claim standing on its own as a separate embodiment of this invention. 
         [0120]    It is also understood that the embodiments of the invention may be practiced in the absence of an element and/or step not specifically disclosed. That is, an inventive feature of the invention may be elimination of an element. 
         [0121]    Accordingly, while the various aspects of the particular embodiments set forth herein have been described in detail, the present invention could be subject to various changes, substitutions, and alterations without departing from the spirit and scope of the invention.