PATENT DOCUMENT

Publication Number: US-11429158-B2
Application Number: US-202117192722-A
Country: US
Kind Code: B2

Title: Sensor assemblies for electronic devices

Abstract:
Sensor assemblies for electronic devices are described. According to some embodiments, the sensor assemblies include solid-state sensors, such as capacitive sensors, piezoelectric sensors or piezoresistive sensors. The sensor assemblies can include a number of features that provide a compact profile, making them well suited for integration into small spaces of electronic device enclosures. The sensor assemblies can also include features that isolate movement of various parts of the sensor assemblies, allowing for accurate detection of a sensing event. According to some embodiments, the sensor assemblies are coupled to haptic actuators, speaker, or both, which mimic the feel of a mechanical button and enhance a user&#39;s experience.

Claims:
What is claimed is: 
     
       1. An electronic device, comprising:
 a housing comprising a wall, the housing defining a first opening, a second opening, and an internal volume; 
 a processor carried by the housing; 
 a speaker disposed at least partially within the internal volume and positioned to direct sound through the first opening; 
 a sensor assembly positioned within the second opening and in communication with the processor, the sensor assembly comprising:
 a sensor cover defining an accessible and movable outer surface; and 
 a light detecting sensor capable of detecting a first movement of the outer surface and providing a first signal in response to the first movement, the first movement exceeding a first distance of about 4 micrometers, the light detecting sensor further capable of detecting a second movement of the outer surface and providing a second signal in response to the second movement, the second movement exceeding a second distance of about 4 micrometers, the second movement being in a different direction than the first movement; and 
 an acoustic component in communication with the light detecting sensor and capable of providing a first sound based on the first movement, and a second sound based on the second movement; 
 wherein the first sound mimics a mechanical component. 
 
 
     
     
       2. The electronic device of  claim 1 , wherein the first sound mimics a first mechanical component, and the second sound mimics a second mechanical component. 
     
     
       3. The electronic device of  claim 2 , wherein the acoustic component produces a clicking sound in response to the first movement. 
     
     
       4. The electronic device of  claim 1 , wherein the wall is a side wall of the housing. 
     
     
       5. The electronic device of  claim 1 , wherein the accessible and movable outer surface is offset from an exterior surface defined by the wall. 
     
     
       6. The electronic device of  claim 1 , wherein the light detecting sensor is capable of detecting a push input on the sensor cover. 
     
     
       7. The electronic device of  claim 1 , wherein the light detecting sensor is capable of detecting a motion of the sensor cover. 
     
     
       8. The electronic device of  claim 1 , wherein the sensor assembly comprises a pre-assembled module. 
     
     
       9. The electronic device of  claim 1 , wherein the speaker is positioned proximate to the sensor assembly. 
     
     
       10. A portable electronic device, comprising:
 a housing carrying a speaker and defining an opening; 
 a processor carried by the housing; 
 a sensor assembly carried by the housing and in communication with the processor, the sensor assembly having a solid-state sensor and a sensor cover, the sensor assembly disposed within the opening, wherein:
 a first movement of the sensor cover in a first direction, in accordance with a first input applied by a user, is detectable by the solid-state sensor; 
 a second movement of the sensor cover in a second direction different than the first direction, in accordance with a second input applied by a user, is detectable by the solid-state sensor; and 
 the sensor assembly is configured to provide a first signal to the processor corresponding to a detection of the first movement exceeding a first distance of about 4 micrometers and a second signal to the processor corresponding to a detection distance of the second movement exceeding a second distance of about 4 micrometers; and 
 
 an acoustic component in communication with the processor, the acoustic component capable of providing, based on the first signal indicative of the first movement exceeding the first distance, an acoustic feedback. 
 
     
     
       11. The portable electronic device of  claim 10 , wherein the housing comprises metal. 
     
     
       12. The portable electronic device of  claim 10 , wherein the speaker is a first speaker and the housing carries a second speaker. 
     
     
       13. The portable electronic device of  claim 10 , wherein the housing is non-transparent. 
     
     
       14. The portable electronic device of  claim 10 , wherein the solid-state sensor is capable of detecting a push input on the sensor cover. 
     
     
       15. A wearable electronic device, comprising:
 a housing comprising a side wall at least partially defining a housing opening and a side wall opening; 
 a processor carried by the housing; 
 a speaker carrier by the housing and positioned to direct sound through the housing opening; 
 a pre-assembled sensor assembly carried by the housing in the side wall opening and in communication with the processor, the sensor assembly comprising:
 a sensor cover disposed within the side wall opening and having an accessible and movable outer surface; and 
 a capacitive sensor capable of detecting a first movement and a second movement of the outer surface and providing a first signal and a second signal in response to the first movement or the second movement, respectively, the first movement being in a first direction and the second movement being in a second direction different than the first direction; and 
 
 an acoustic component in communication with the processor and capable of providing an acoustic feedback in response to a command from the processor based on the first signal. 
 
     
     
       16. The wearable electronic device of  claim 15 , wherein the acoustic component is capable of producing a clicking sound. 
     
     
       17. The wearable electronic device of  claim 15 , wherein the capacitive sensor is capable of detecting a motion of the sensor cover. 
     
     
       18. The wearable electronic device of  claim 15 , wherein the acoustic component is proximate to the sensor assembly.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     The present application is a continuation of U.S. application Ser. No. 16/586,678, filed Sep. 27, 2019, entitled “SENSOR ASSEMBLIES FOR ELECTRONIC DEVICES,” which is a continuation of U.S. application Ser. No. 15/844,162, filed Dec. 15, 2017, now U.S. Pat. No. 10,488,891 issued Nov. 26, 2019, which is a continuation of U.S. application Ser. No. 15/449,810, filed Mar. 3, 2017, entitled “SENSOR ASSEMBLIES FOR ELECTRONIC DEVICES,” now U.S. Pat. No. 9,870,033 issued Jan. 16, 2018, which claims the benefit of U.S. Provisional Application No. 62/381,525, entitled “SENSOR ASSEMBLIES FOR ELECTRONIC DEVICES” filed on Aug. 30, 2016; U.S. Provisional Application No. 62/384,083, entitled “SENSOR ASSEMBLIES FOR ELECTRONIC DEVICES” filed on Sep. 6, 2016; and U.S. Provisional Application No. 62/424,300, entitled “SENSOR ASSEMBLIES FOR ELECTRONIC DEVICES” filed on Nov. 18, 2016, all of which are hereby incorporated by reference. 
    
    
     FIELD 
     The described embodiments relate to sensor assemblies suitable for consumer electronic devices. According to some embodiments, the sensor assemblies include solid-state sensors, such as capacitive touch sensors. 
     BACKGROUND 
     Conventional mechanical switches are used in numerous applications in electronic products. For example, many button and keyboard designs include mechanically based actuators that rely on relatively large movements to complete electrical circuits. Advantages of mechanical switches include their low cost and ability to provide audible and tactile response to a user. However, mechanical switches are relatively large in size and, therefore, are difficult to integrate into products that have very limited space. This can be a major obstacle for integrating into modern portable electronic products, which include a multitude of electronic components packed within small enclosures. Furthermore, mechanical switches can wear out quickly, and therefore may need frequent replacing. What are needed, therefore, are improved sensor and actuator designs for electronic devices. 
     SUMMARY 
     This paper describes various embodiments that relate to sensor assemblies for electronic devices. In particular embodiments, the sensor assemblies include solid-state sensors that require small deflections for activation and have small cross-section profiles. 
     According to a further embodiment, an electronic device is described. The electronic device includes a speaker and a haptic component. The electronic device also includes a display cover that covers a display of the electronic device. The display cover has an opening. The electronic device further includes a sensor assembly for accepting input for the electronic device. The sensor assembly includes a sensor cover positioned within the opening of the display cover and having an outer surface configured to accept the input. The sensor assembly also includes a sensor configured to detect the input. The sensor generates one or more signals that activate the haptic component and the speaker in response to the input. 
     According to one embodiment, a sensor assembly for detecting and responding to input is described. The sensor assembly includes a sensor cover having an exterior surface for accepting the input. The sensor assembly also includes a trim that encompasses a perimeter. The sensor assembly further includes a compliant member positioned between the sensor cover and a ledge of the trim. The compliant member is configured to compress and provide a return force in response to the input. The sensor assembly additionally includes a capacitive touch sensor configured to detect the input. 
     According to another embodiment, an electronic device is described. The electronic device includes a display cover that covers a display of the electronic device. The display cover has an opening defining an interior chamfered edge. The electronic device also includes a sensor assembly for accepting input for the electronic device. The sensor assembly includes a sensor cover positioned within the opening and having an outer surface configured to accept the input. The sensor assembly also includes a trim positioned within the opening between the sensor cover and the display cover. The trim has an exterior chamfered edge that engages with the interior chamfered edge of the display cover. The sensor assembly further includes a sensor configured to detect the input. 
     These and other embodiments will be described in detail below. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The disclosure will be readily understood by the following detailed description in conjunction with the accompanying drawings, wherein like reference numerals designate like structural elements. 
         FIGS. 1A and 1B  show perspective views of consumer electronic devices that can include sensor assemblies described herein. 
         FIG. 2  shows an exploded view of a portion an electronic device with a sensor assembly in accordance with some embodiments. 
         FIGS. 3A and 3B  show top views of a sensor assembly portion of an electronic device of show in  FIG. 1A . 
         FIG. 4A  shows a cross-section view of the sensor assembly portion of the electronic device shown in  FIG. 3B . 
         FIG. 4B  shows a top view of an electronic device having a sensor assembly, a haptic engine and a speaker. 
         FIG. 5  shows a cross-section view of a sensor assembly portion of an electronic device in accordance with some embodiments. 
         FIG. 6  shows a flowchart indicating a process for assembling a sensor assembly within an electronic device in accordance with some embodiments. 
         FIGS. 7A-7C  show cross-section views of sensor assembly mounting configurations, in accordance with some embodiments. 
         FIGS. 8A-8E  show cross-section views of sensor assembly sealing configurations, in accordance with some embodiments. 
         FIGS. 9A-9C  show cross-section and top views of a trimless sensor assembly configuration, in accordance with some embodiments. 
         FIGS. 10A-10D  show cross-section and top views of a vibrating sensor assembly configuration, in accordance with some embodiments. 
         FIGS. 11A-11C  show cross-section views of sensor assemblies having different sensing configurations, in accordance with some embodiments. 
         FIG. 11D  shows a perspective view of a bracket as part of sensor assembly configuration of  FIG. 11C , in accordance with some embodiments. 
         FIGS. 12A and 12B  show cross-section views of a portion of an electronic device with a sensor assembly before and during a bonding operation, respectively. 
         FIGS. 13A-13F  show sensor assembly configurations for preventing adhesive overflow from occurring during a bonding operation, in accordance with some embodiments. 
     
    
    
     DETAILED DESCRIPTION 
     Reference will now be made in detail to representative embodiments illustrated in the accompanying drawings. It should be understood that the following descriptions are not intended to limit the embodiments to one preferred embodiment. To the contrary, it is intended to cover alternatives, modifications, and equivalents as can be included within the spirit and scope of the described embodiments as defined by the appended claims. 
     Described herein are features of sensor assemblies that are well suited for consumer products, such as portable electronic devices. According to some embodiments, the sensor assemblies include solid-state sensors. Compared to conventional mechanical switches and buttons that depend on physical contact between contact pads, solid-state sensors utilize voltage or capacitive changes to switch between on and off modes. This aspect makes solid-state sensors less likely to wear out compared to mechanical switches. In addition, solid-state sensors are generally more compact than mechanical switches and buttons, making them well suited for integration within small form factor enclosures, such as those for portable electronic devices. 
     Furthermore, solid-state pressure sensor designs can require very small movements and forces in order to activate compared to mechanical switches and buttons. Since the sensor assemblies involve minimal or little movement (e.g., 10 micrometers or less, sometimes 5 micrometers or less), a user may not perceive movement of the sensor assembly (e.g., button) itself when pressed. Thus, the sensor assembly can be configured to provide tactile feedback (output) to the user in response to a user&#39;s touch input, which this gives the user the experience that the button has been depressed and activated, even if the sensor assembly barely moves. Examples of tactile feedback can include haptic (e.g., vibratory) feedback. In some instances, a signal to the user is in the form of acoustic or sonic feedback (i.e., makes a sound). In some cases, the sensor assembly is configured to provide a combination of tactile and acoustic feedback. These feedback features can mimic the experience of activating a mechanical switch or button, thereby providing a pleasing experience for a user. Furthermore, the sensor assembly can provide tactile feedback in response to a user&#39;s tactile input (e.g., user&#39;s touch), giving the user an engaging and satisfying sensation and experience with the electronic device. 
     The sensor assemblies described herein can include a number of features that enhance performance of the sensor assemblies when integrated within electronic devices. For example, a trim that surround a sensor cover or cap can prevent lateral movement of the sensor assembly and isolate movement of portions of the sensor assembly to a direction toward or away from a touch sensor. 
     The sensor assemblies described herein are well suited for integration into consumer products such as computers, portable phones, tablet devices, wearable electronic devices, and electronic device accessories, such as those manufactured by Apple Inc., based in Cupertino, Calif. 
     These and other embodiments are discussed below with reference to  FIGS. 1A-13F . However, those skilled in the art will readily appreciate that the detailed description given herein with respect to these Figures is for explanatory purposes only and should not be construed as limiting. 
       FIGS. 1A and 1B  show consumer products than can include sensor assemblies such as those described herein.  FIG. 1A  shows portable phone  102 , and  FIG. 1B  shows tablet computer  104 , each of which includes sensor assemblies  106  configured to sense input from a user. Sensor assemblies  106  can be configured to activate one or more electrical circuits within respective devices  102  or  104 , and therefore may be referred to as button assemblies or switch assemblies. For example, sensor assemblies  106  may be configured to activate aspects of displays  108  of devices  102  and  104 , respectively. Sensor assemblies  106  can be designed to cosmetically enhance the appearance of enclosures  110  of devices  102  and  104 . In some cases, sensor assemblies  106  are integrated with display covers  112  of enclosures  110 . 
     Sensor assemblies  106  can include one or more sensors for detecting of input (e.g., touch, push, motion, light). In some cases, the sensors includes one or more capacitive, piezoelectric and piezoresistive sensors. In some cases, sensor assemblies  106  are configured to provide output to a user, such as haptic or acoustic feedback, to indicate that sensor assemblies  106  are activated in response to the input. In some embodiments, sensor assemblies  106  include fingerprint sensors that can detect and distinguish between fingerprints of different users. It should be noted that the sensor assemblies described herein can be integrated within any suitable electronic device and are not limited to devices  102  and  104  shown in  FIGS. 1A and 1B . For example, the sensor assemblies can be implemented in laptop computers or wearable electronic devices. 
       FIG. 2  shows an exploded view of a portion of an electronic device (e.g., portable phone  102 ), showing how sensor assembly  106  is configured to fit within opening  201  of display cover  112 . Display cover  112  can correspond to a transparent or partially transparent material that covers and protects an underlying display assembly. Display cover  112  can be composed of glass (e.g., sapphire), plastic, ceramic, and/or other suitable material. In some cases, display cover  112  is coupled with another portion of an enclosure for the portable phone (e.g., a metal portion of the enclosure) using fastening features  208 . Bracket  210  can be used to secure sensor assembly  106  to display cover  112  via fasteners  211 . It should be noted that the sensor assembly  106  can be inserted within an opening of any suitable portion of an electronic device and is not limited to integration with a display cover. For example, sensor assembly  106  can be inserted within an opening of a non-transparent enclosure wall of an electronic device. 
     As shown, sensor assembly  106  can in a pre-assembled in modular form for ease of assembly into an electronic device. Sensor assembly  106  includes sensor portion  205  and cable portion  207 . Sensor portion  205  can include a sensor that is configured to detect input (e.g., touch, push, motion, light). In some cases the sensor is configured to detect touch or push input from a user&#39;s finger. In some instances the sensor includes one or more capacitive, piezoelectric and piezoresistive sensors. In some cases, sensor assembly  106  includes a fingerprint sensor configured to detect a users fingerprint. Cable portion  207  can include wiring that electrically connects sensor portion  205  to other electrical components within the electronic device. In some embodiments, cable portion  207  includes one or more flexible (flex) cables. Sensor cover  202  corresponds to a cosmetic cover having an exterior or outer surface configured to accept input. In some embodiments, sensor cover  202  is at least partially transparent such that an underlying fingerprint sensor can detect patterns of the user&#39;s fingerprint. 
     A perimeter of sensor cover  202  is encompassed by trim  204 , which can correspond to a rigid ring or frame having an aperture to accommodate sensor cover  202 . In some cases, an intermediate layer, such as an adhesive or polymer layer, is positioned between sensor cover  202  and display cover  112 . In other cases, trim  204  is configured to directly engage with sensor cover  202  and display cover  112  so as to provide a tight fit. In some embodiments, trim  204  is composed of a metal material, which can provide sufficient rigidity without being too brittle. However, in some cases trim is composed of other rigid materials such as polymer or ceramic materials. As described in detail below, trim  204  can limit motion of the sensor assembly  106  once assembled within display cover  112 . In addition, trim  116  is visible to a user, and therefore can enhance the appearance of sensor assembly  106 . Due to its multiple functions, trim  116  can be referred to as a bracket, brace, support, washer, ring, band or other suitable term. 
     Sensor assembly  106  can be configured for easy assembly and disassembly. For example, sensor assembly  106  can be assembled from the top side of opening  201 , and bracket  210  can be assembled from the bottom side of opening  201 , as shown in  FIG. 2 . Bracket  210  can be composed of metal that is grounded to the enclosure of electronic device, and non-conductive portion  212  of bracket  210  electrically isolates the conductive portions of bracket  210  from sensor assembly  106 . Since cable portion  207  should be positioned beneath display cover  112 , cable portion  207  can be threaded through opening  201 , then trim  204  and sensor cover  202  can be adjusted to fit snugly within opening  201 . Fasteners  211  can then be used to secure bracket  210 , which supports sensor assembly  106 , to display cover  112 . In the embodiment of  FIG. 2 , fasteners  211  are screws, but may alternatively or additionally include clips, press-fit fasteners, welds, or other suitable fasteners. In some cases, fastener  211   a  is aligned with a center of opening  201  and sensor cover  202 . 
     It should be noted that the shape of sensor assembly  106  could vary depending on design requirements. In particular, sensor cover  202  and trim  204  are not limited to round or circular forms as shown. For example, sensor cover  202  and trim  204  can have rectangular, triangular, oval or any other suitable shapes. 
       FIGS. 3A and 3B  show top views of a portion of electronic device  102  having sensor assembly  106 .  FIG. 3B  shows sensor assembly  106  with sensor cover  202 , and  FIG. 3A  shows sensor assembly  106  without sensor cover  202 .  FIG. 3A  shows that sensor component  304  is positioned beneath sensor cover  202 . In some embodiments, sensor component  304  is a fingerprint sensor or touch sensor. Surrounding sensor component  304  is compliant member  302 , which corresponds to one or more layers of compliant or resilient material, such a silicone or other polymer. In some cases, compliant member  302  includes separate pieces—in this case, four circle segment-shaped pieces to accommodate a rectangular-shaped sensor component  304 . It should be noted, however, that compliant member  302  can have any suitable shape and include any suitable number of pieces.  FIG. 3B  shows sensor assembly  106  fully assembled within electronic device  102 . As shown, sensor cover  202  is surrounded by trim  204 , both of which are exposed to a user of electronic device  102 . Sensor cover  202  also provides a contact surface for a user to contact and activate sensor assembly  106 . 
       FIG. 4A  shows a cross-section view (A-A in  FIG. 3B ) of a portion of electronic device  102 , showing how sensor assembly  106  can be assembled within electronic device  102 , in accordance with some embodiments. Trim  204  is positioned between sensor cover  202  and display cover  112 , which is, in turn, coupled to enclosure portion  110 . As shown, sensor assembly  106  has a very thin cross-section, thereby making room for components such as component  414 . In one particular embodiment, component  414  is a driver as part of a display assembly. Trim  204  includes ledge  404 , which supports the backside of sensor cover  202 . Compliant member  302 , which has a thickness t, is positioned between sensor cover  202  and ledge  404  of trim  204 . Compliant member  302  can be adhered to sensor cover  202  and ledge  404  by adhesive layers (not shown), such as layers of heat activated film, pressure sensitive adhesive, liquid adhesive, or other suitable adhesive material. In some embodiments, compliant member  302  includes holes or channels that accommodate overflow of the adhesive. 
     Inset  400  shows a detail cross-section view of a stack up of sensor assembly  106 . Beneath sensor cover  202  is fingerprint sensor  304 , which is configured to scan a fingerprint of a user through sensor cover  202 . In some cases, fingerprint sensor  304  is a silicon chip having an array of capacitors and that is in communication with software that can capture a user&#39;s fingerprint image and match it with stored fingerprint data. Fingerprint sensor  304  can be coupled to sensor cover  202  by adhesive  407 , which can be an optically transparent adhesive or other suitable adhesive. 
     Beneath fingerprint sensor  304  is touch sensor  402 , which in the embodiment of  FIG. 4A  is a capacitive touch sensor that includes first layer  402   a  and second layer  402   b . Capacitor module  423  is associated with touch sensor  402 . In some embodiments, first layer  402   a  and second layer  402   b  each correspond to flat flexible materials that include a layer of conductive material (e.g., copper) or other suitable material (e.g., indium tin oxide (ITO)) that are capacitively coupled with respect to one another. First layer  402   a  is physically coupled to fingerprint sensor  304  by first adhesive layer  408 , and second layer  402   b  is physically coupled to stiffener  405  by second adhesive layer  409 —which can be different or the same types of adhesives. First layer  402   a  and second layer  402   b  are spaced apart by gap  406  having a distance d such that a change in distance d is detected by a voltage or capacitive change. Distance d can vary depending on design and manufacture of touch sensor  402 . Gap  406  can be filled with air or other a non-conductive material, such as a compliant gel. In some embodiments, air is found to provide better sensing capability than a gel. 
     When a user touches exterior surface  413  of sensor cover  202 , the force is transferred to first layer  402   a  in a direction  403  toward sensor  402  (referred to as a sensing direction) and into a pressed position. This, in turn, causes a corresponding reduction in distance d between capacitive layers  402   a  and  402   b , thereby causing a change in voltage or capacitance in touch sensor  402 . Touch sensor  402  then generates a signal that activates one or more electrical circuits of electronic device  102 . Compliant member  302  is composed of a compliant material that provides a resistive force (opposite sensing direction  403 ) that returns sensor cover  202 , and therefore also first layer  402   a , back to its un-pressed position. Once sensor cover  202  is back in its un-pressed position, compliant member  302  returns to its full thickness t. Since there is very little space for compliant member  302 , thickness t should be very thin. In some cases, thickness is no more than about 500 micrometers—in some cases, ranging from about 50-100 micrometers. 
     The change in distance d sufficient to cause activation of touch sensor  402  will depend on the design of touch sensor  402 . In general, the required change in distance d will be very small. In some cases, the change in distance d is about 2-3 micrometers (corresponding to a compliance of about 5-10 nm/gram-force for touch sensor  402 ). Ledge  404  of trim  204  acts as a hard stop that prevents the amount of movement of sensor cover  202  in sensing direction  403 . In particular, ledge prevents first layer  402   a  from contacting second layer  402   b , or otherwise allowing first layer  402   a  to come too close to second layer  402   b . In some cases, deflection in the material of sensor cover  202  when pressed by a user can also contribute to changes in distance d. However, this aspect can be factored into the design of sensor assembly  106 . In some embodiments, sensor cover  202  is composed of a rigid material, such as glass (e.g., sapphire), ceramic or rigid polymer, so as to reduce material deflection effects of sensor cover  202 . In some embodiments, sensor cover  202  moves from the un-pressed position to the pressed position by a distance of less than about 50 micrometers sensing direction  403 . In some cases, sensor cover  202  moves from the un-pressed position to the pressed position by a distance of less than about 10 micrometers. In a particular embodiment, sensor cover  202  moves from the un-pressed position to the pressed position by a distance of about 4 micrometers. 
     Note that the embodiments described herein are not limited to capacitive sensors. For example, instead of, or in addition to, a capacitive touch sensor  402 , sensor assembly  106  can include a piezoelectric or piezoresistive sensor. That is, any suitable solid-state sensors may be used. 
     Compared to conventional mechanical switches and buttons, sensor assembly  106  requires very little physical movement with the assembly itself for activation. This allows for sensor assembly  106  to have a much more compact cross-section (z-stack) compared to mechanical switches and buttons, thereby providing more room for other components within electronic device  102 , such as component  414 . Furthermore, sensor assembly  106  may not depend on mechanical contact within touch sensor  402 . Instead, sensor  402  can utilize small voltage or capacitance changes brought about by a relatively small force input, which may be accomplished using a solid-state sensor. In general, solid-state sensors, such as capacitive touch, piezoelectric and piezoresistive sensors, can include electrical circuits built within solid material, such as semiconductor materials. The relatively non-mechanical aspect of solid-state sensors can make sensor assembly  106  less likely to wear out compared to conventional mechanical switches and buttons. Moreover, since sensor assembly  106  may require a small force for activation compared to mechanical switches and buttons, this can provide an easier input means for electronic device  102  and a better user experience. Furthermore, since the solid-state sensor can require less movement in the sensing direction  403  compared to mechanical switches, the cross-section of sensor assembly  106  can be smaller (thinner) than that of a mechanical switch assembly. 
     Other design considerations include features that isolate movement of sensor cover  202  when transitioning between the pressed and un-pressed positions. For example, tight engagement of trim  204  with display cover  112  and sensor cover  202  prevents lateral movement of sensor assembly  106  with respect to sensing direction  403 . Thus, trim  204  should have a size and shape in accordance with the size and shape of each of sensor cover  202  and the opening of display cover  112 . Furthermore, stiffener  405  provides rigid support for second layer  402   b  of touch sensor  402 . Stiffener  405  is coupled to trim  204  via fastening members  418 , which in some embodiments are weld spots. This is because in some cases welding is found to provide the strongest bond and provide the most reliable rigidity within the limited space provided for sensor assembly  106 . The combination of the above structural features and bracket  210  prevents sensor assembly  106  from encroaching into internal cavity  412  and making contact with component  414  during drop events and other large force events. 
     In the embodiment of  FIG. 4A , trim  204  has a chamfered edge  410  that corresponds to a chamfered edge  411  of display cover  112 . This chamfered design creates a hard stop such that sensor assembly  106  is not able to intrude within internal cavity  412  of enclosure  110 . In particular, although bracket  210  and fastener  211   a  support and secure sensor assembly  106  to display cover  112 , the matching chamfered geometries of trim  204  and display cover  112  further prevent shifting of sensor assembly  106  and encroachment of sensor assembly  106  into internal cavity  412 . These chamfered geometries can have an advantage over a stepped geometry for manufacturing purposes. In particular, a stepped geometry is more difficult to polish than a chamfered geometry. Furthermore, the angled geometry allows for more flexibility with regard to stack up tolerance compared to stepped geometry. In some embodiments, chamfered edges  410  and  411  are each chamfered by about 45 degrees with respect to outer surface  425  of display cover  112 . In some embodiments, sensor assembly  106  is installed such that exterior surface  413  of sensor cover  202  is slightly recessed with respect to outer surface  425  of display cover  112  (in some cases, recessed by about 100 micrometers). This recessed configuration of sensor cover  202  can help prevent inadvertent activation (i.e., false triggers) of sensor assembly  106 . 
     In some embodiments, sensor assembly  106  is configured to provide feedback to a user. For example, sensor assembly  106  can be electrically coupled to haptic actuator  415  (which can be referred to as a haptic component) that causes electronic device  102  to vibrate. This type of haptic feedback is sometimes referred to as taptic feedback, and haptic actuator  415  can be referred to as a taptic engine. Additionally or alternatively, sensor assembly  106  can be electrically coupled to speaker  416  that provides acoustic feedback to the user. In some cases, the combination of both haptic feedback and acoustic feedback creates an experience for a user that mimics depression of a mechanical button or switch. In one embodiment, sensor assembly  106  causes speaker  416  to produce a very quiet, high pitch and crisp sound that mimics the sound of mechanical button being pressed, and causes haptic actuator  415  to produce a very brief vibration that mimics the feel of a mechanical button being pressed. In some cases, haptic actuator  415  is able to vibrate and also produce a sound without the addition of sound from speaker  416 . 
     Haptic actuator  415  and speaker  416  can be located in any suitable part of electronic device  102 . For example, haptic actuator  415  can positioned at a distal side (not shown) of electronic device  102  with respect to sensor assembly  106 , and can be activated by other electronic components of electronic device  102 . Likewise, speaker  416  can be positioned on a sidewall (not shown) of electronic device  102 , and can be used to provide other sounds (e.g., ring tones and alerts) to a user. That is, sensor assembly  106  can activate haptic actuator  415  and/or speaker  416 , which are already components of electronic device  102  for other purposes. In other embodiments, haptic actuator  415  and/or speaker  416  are dedicated feedback components for sensor assembly  106 . In these designs, it may be beneficial to position haptic actuator  415  and/or speaker  416  adjacent to sensor assembly  106 . 
     In some embodiments, one or more sealing features provide a moisture barrier from the external environment. For example, seal  420  positioned around an internal perimeter of trim  204  adjacent to compliant member  302  can prevent moisture from the external environment from entering between sensor cover  202  and trim  204  and contacting fingerprint sensor  304  or touch sensor  402 , or from entering internal cavity  412 . Since seal  420  is positioned adjacent to compliant member  302 , the material of seal  420  should be compliant enough to prevent interference with the compressing and decompressing of compliant member  302 . In some cases, seal  420  is composed of a very compliant polymer adhesive, such as a silicone-based adhesive. 
     Seal  421  can prevent moisture from entering internal cavity  412  between trim  204  and display cover  112 . In some cases, seal  421  is in the form of an O-ring that is positioned within groove  422  at an outer perimeter of trim  204 . If seal  421  is an O-ring, the diameter of the O-ring may need to be smaller than conventionally manufactured since space is so limited in and around sensor assembly  106 . In a particular embodiment, the diameter of the O-ring seal  421  is less than about 0.5 millimeters. 
       FIG. 4B  shows a top view of a portion of device  102  indicating location of sensor assembly  106  in relation to haptic actuator  415  and speaker  416 , in accordance with some embodiments. As shown, haptic actuator  415  and speaker  416  can be separate electronic components housed within enclosure  110 . In some cases, haptic actuator  415  and speaker  416  are positioned proximate to and partially under sensor assembly  106 . In some instances, haptic actuator  415  and speaker  416  each serve functions other than solely dictated by sensor assembly  106 . For example, haptic actuator  415  can provide tactile feedback to a user (e.g. by vibrating enclosure  110 ) in response to other types of input from a user, such as touch input from the user contacting display  417 , or any other suitable signal as dictated by device  102  (e.g. phone call, text messages, alarm, etc.). In some cases haptic actuator  415  makes a sound when vibrating, thereby also providing acoustic feedback to a user. Speaker  416  can be arranged to produce sound that is directed through one or more openings  419  within enclosure  110 . Speaker  416  can produce sound  427  in response any suitable signal as dictated by device  102  (e.g. user input, phone call, text messages, alarm, etc.). Thus, haptic actuator  415  and speaker  416  can each have multiple uses and are not solely dedicated to the service of sensor assembly  106 . In some embodiments, however, haptic actuator  415  and speaker  416  are fully dedicated to the responding to signals from sensor assembly  106 . 
     It should be noted that the locations of haptic actuator  415  and speaker  416  of device  102  can vary depending on design needs and are not limited to the locations depicted in  FIG. 4B . In some designs it may be beneficial to have haptic actuator  415  and speaker  416  positioned proximate to sensor assembly  106  so that the user can more readily associate vibrations of haptic actuator  415  and noises of speaker  416  with pressing of sensor assembly  106 . However, in some cases, it may be beneficial to have haptic actuator  415  and speaker  416  positioned in different locations within device  102 . For example, in some designs one or both haptic actuator  415  and speaker  416  can be located at an opposing side of device  102  than the location of sensor assembly  106 . Furthermore, the number of haptic actuators  415  and speakers  416  can vary, depending on desired user experience and design requirements. 
       FIG. 5  shows a cross-section view of a portion of electronic device  500 , which includes sensor assembly  506 , in accordance with some embodiments. Sensor assembly  506  is assembled within an opening of enclosure portion  512 . In some embodiments, enclosure portion  512  corresponds to a display cover that covers a display assembly of electronic device  500 . Sensor assembly  506  includes fingerprint sensor  524  and touch sensor  522 . Fingerprint sensor  524  is configured to recognize fingerprint features of a user through sensor cover  502 . Touch sensor  522  is configured to detect input, such as from a user&#39;s finger touching exterior surface  513  of sensor cover  502 . Touch sensor  522  can be any suitable solid-state sensor capable of detecting a touch input. In some embodiments, touch sensor  522  includes one or more of a capacitive sensor, piezoelectric sensor and piezoresistive sensor. The small cross-section of sensor assembly  506  allows for more room within enclosure  512  for other components, such as electronic component  514 . 
     Trim  504  encompasses a perimeter of sensor cover  502  and isolates movement of the sensor cover  502  between a pressed position and an un-pressed position. In particular, trim  504  prevents lateral movement of sensor cover  502  so as to limit movement of sensor cover  502  to sensing direction  503  (toward touch sensor  522 ) and a direction opposite sensing direction  503  (away from touch sensor  522 ). Compliant member  508  is positioned between sensor cover  502  and ledge  532  of trim  504 . Compliant member  508  can be in the form of a single piece or multiple pieces (e.g., see compliant member  302  in  FIG. 3A ). When a user applies a force on exterior surface  513  of sensor cover  502 , thickness t of compliant member  508  compresses accordingly. Compliant member  508  is configured to provide a return force that returns sensor cover  502  back to the un-pressed position from the pressed position. 
     Sensor cover  502  is coupled to first layer  522   a  of touch sensor  522 , and stiffener  505  is coupled to second layer  522   a  of touch sensor  522 . Stiffener  505  is rigidly coupled to enclosure portion  512  via trim  504 , thereby keeping second layer  522   b  stationary with respect to enclosure portion  512 . Thus, when sensor cover  502  moves in sensing direction  503  to a pressed position in response to a force, distance d of gap  507  between first layer  522   a  and second layer  522   a  is reduced, thereby causing a voltage or capacitance shift within touch sensor  522 . In some cases, this voltage or capacitance change causes touch sensor  522  to generate a signal that activates one or more components. When compliant member  508  returns sensor cover  502  to the un-pressed position, gap  507  returns to its original distance d, thereby returning the voltage or capacitance to the original voltage. In some cases, the voltage or capacitance change causes touch sensor  522  to generate a signal that deactivates the one or more components, and/or that activates one or more other components. 
     In some embodiments, sensor assembly  506  is electrically coupled to haptic actuator  515  and/or speaker  516 . This configuration allows a touch event from a user to be associated with haptic and/or acoustic feedback to the user. For example, sensor assembly  106  can cause speaker  516  to produce a clicking sound, and/or cause haptic actuator  515  to produce a very brief vibration that simulates pushing of a mechanical switch. Haptic actuator  515  and speaker  516  can be part of sensor assembly  506  itself, or be situated in a different region of electronic device  500 . 
       FIG. 6  shows a flowchart indicating a process for assembling a sensor assembly within an electronic device. At  602 , a trim is positioned around a perimeter of a sensor cover of a sensor assembly. The sensor cover can have a round, rectangular, triangular, oval or other suitable shape, with the trim having a correspondingly shaped aperture. At  604 , one or more moisture seals positioned around the trim. In one embodiment, moisture seal has an O-ring shape and is positioned within a groove at an outer perimeter of the trim. The moisture seal can be composed of a compliant material, such as silicon or other polymer material. 
     At  606 , the sensor assembly is positioned within an opening of an enclosure for an electronic device. The sensor assembly can be assembled within a wall of the enclosure, such as a transparent, glass display cover for the electronic device, or an opaque metal or plastic wall of the enclosure. The opening should have a shape corresponding to that of the outer perimeter of the trim such that a tight fit between the two is achieved. In some cases, the sensor assembly is assembled from a top side of the opening while a bracket is assembled from a bottom side of the opening  201 . In some cases, this involves bending and threading a cable portion of the sensor assembly within the opening before adjusting the trim and the sensor cover snugly within opening. In some cases, a top surface of the sensor cover is recessed with respect to a top surface of the enclosure. 
     At  608 , the sensor assembly is secured to the enclosure. In some embodiments, the bracket supports a bottom portion of the sensor assembly with respect to the enclosure. Fasteners, such as screws or welds, can be used to secure the bracket and the sensor assembly to the enclosure. In some cases, the fasteners are tightened in a manner such that chamfered interfaces between the trim and enclosure tightly engage with one another. 
       FIGS. 7A-7C  show cross-section views of sensor assembly mounting configurations, in accordance with some embodiments.  FIG. 7A  shows sensor assembly  706 , which is assembled within electronic device  700 . Sensor assembly  706  includes sensor cover  702  having a perimeter that is encompassed by trim  704 . Trim  704  is positioned between and engages both sensor cover  702  and enclosure portion  712 . In some embodiments, enclosure portion  712  corresponds to a display cover that covers a display assembly of electronic device  700 . As show, trim  704  has a chamfered edge  707 , which engages with corresponding chamfered edge  708  of enclosure portion  712 . In some cases, the geometries of chamfered edges  707  and  708  are chosen such that exterior surface  711  of sensor cover  702  is recessed with respect to exterior surface  713  of enclosure portion  712 . The chamfered edge mounting configuration shown in  FIG. 7A  is similar to that of  FIG. 4A , described above. 
     One of the advantages of the mounting configuration of  FIG. 7A  is chamfered edge  707  of trim  704  can secure sensor cover  702  around its full perimeter, thereby preventing a user from being able to push sensor assembly  706  into internal cavity  715  or putting pressure onto electronic component  714 . This can be of particular importance if electronic component  714  includes relatively fragile components, such as a silicon chip. In some embodiments, electronic component  714  includes a driver as part of a display assembly. Furthermore, chamfered edges  707  and  708  secures sensor assembly  706  so well that sensor assembly  706  does not encroach within cavity  715  or put significant pressure on electronic component  714  even when electronic device  700  experiences a drop event or other high impact events. Another advantage of the mounting configuration of  FIG. 7A  is that chamfered edges  707  and  708  can localize the pressure from a user&#39;s finger in a sensing direction  703 . 
       FIG. 7B  shows sensor assembly  726  is assembled within electronic device  720 . Instead of a trim, sensor assembly  726  is supported by back plate  724 . Back plate  724  is coupled to both sensor cover  722  and enclosure portion  732 , and is positioned below sensors  726  and  727 . In some embodiments, sensor  726  corresponds to a portion of a touch sensor and sensor  727  corresponds to a portion of a fingerprint sensor. Back plate  724  can be coupled to enclosure portion  732  and/or sensor cover  722  by an adhesive or by engagement from an insert molding process. For example, back plate  724  can be composed of a plastic material that is molded onto enclosure portion  732 . In some embodiments, exterior surface  731  of sensor cover  722  is recessed with respect to exterior surface  733  of enclosure portion  732 . 
     One of the advantages of the mounting configuration of  FIG. 7B  is that back plate  724  can be not visible to a user, which may provide a cosmetic advantage in some applications. Furthermore, this configuration can localize the pressure from a user&#39;s finger to a sensing direction  723 . Moreover, because of its position, back plate  724  can provide strong support for sensor assembly  726  such that sensor assembly  726  does not encroach in internal cavity  735  or contact electronic component  734 . However, this configuration may provide less support at the top of sensor assembly  726  than those embodiments that include a trim. This factor may not be important, however, depending on the particular application and other design considerations of electronic device  720 . 
       FIG. 7C  shows sensor assembly  746  is assembled within electronic device  720 . In this embodiment, enclosure portion  752  corresponds to a display cover that covers a display assembly of electronic device  740 . In a particular embodiment, at least part of enclosure portion  752  is at least partially transparent such that the underlying display is viewable through enclosure portion  752 . Instead of a separate sensor cover, enclosure portion  752  covers sensor assembly  746 . That is, part of enclosure portion  752  acts as a sensor cover. In some embodiments, the portion covering sensor assembly  746  is locally thinned so as to provide a recess  742  within enclosure portion  752 . Recess  742  may be detectable by a user when the user touches enclosure portion  752  (and in some cases visually detectable by a user) and act as a guide so that the user can locate sensor assembly  746 . In other embodiments, recess  742  is located within an interior surface of enclosure portion  752  (i.e., backside of enclosure portion  752  adjacent to sensor  747 . 
     One of the advantages of the mounting configuration of  FIG. 7C  is that enclosure portion  752  provides a continuous surface that covers the display and sensor assembly  746  of electronic device  740 . This can provide good protection to sensor assembly  746  from liquids or other agents without the use of seals. Furthermore, the continuous surface of enclosure portion  752  may be cosmetically appealing in some applications. However, this configuration may limit the movement of sensor assembly  746  in sensing direction  743 . In particular, since enclosure portion  752  cover sensor assembly  746 , movement of sensor assembly  746  in sensing direction  743  depends on deflection of the material of enclosure portion  752 , which can limit the amount of movement in sensing direction  743 . Depending on the material of enclosure portion  752 , this can make it more difficult for a user to depress sensor assembly  746  sufficiently for actuation. Furthermore, if the material of enclosure portion  752  is sufficiently flexible, a user&#39;s touch input may cause sensor assembly  746  to encroach into internal cavity  755  or touch electronic component  754 . These factors may not be important, however, depending on the particular application and other design considerations of electronic device  740 . 
       FIGS. 8A-8E  show cross-section views of sensor assembly sealing configurations, in accordance with some embodiments.  FIG. 8A  shows sensor assembly  806  positioned within an opening of enclosure portion  812  of electronic device  800 . For simplicity, sensor assembly  806  and trim  804  are shown as a single block. Inset  802  shows a detailed view of an interface region between trim  804  and enclosure portion  812 , at which seal  808  is positioned. Seal  808  prevents moisture from entering between trim  804  and enclosure portion  812 . In some cases, seal  808  is in the form of an O-ring that is positioned within groove  810  at an outer perimeter of trim  804 . The embodiment shown in  FIG. 8A  has a similar sealing configuration as that of  FIG. 4A . 
       FIG. 8B  shows sensor assembly  826  positioned within an opening of enclosure portion  832  of electronic device  820 . For simplicity, sensor assembly  826  and trim  824  are shown as a single block. Inset  822  shows a detailed view of an interface region between trim  824  and enclosure portion  832 , at which adhesive  828  is positioned Like seal  808  described above, adhesive  828  prevents moisture from entering between trim  824  and enclosure portion  832 . Adhesive  828  can be composed of any suitable adhesive, including one or more of heat activated film, pressure sensitive adhesive, liquid adhesive, or other suitable adhesive material. In some embodiments, trim  834  includes groove  830  that accommodates adhesive  828 . 
       FIG. 8C  shows sensor assembly  846  positioned within an opening of enclosure portion  852  of electronic device  840 . For simplicity, sensor assembly  846  and trim  844  are shown as a single block. Inset  842  shows a detailed view of an interface region between trim  844  and enclosure portion  852 , at which adhesive  848  is positioned. Adhesive  848  prevents moisture from entering between trim  844  and enclosure portion  852 . Adhesive  848  can be composed of any suitable adhesive, including one or more of heat activated film, pressure sensitive adhesive, liquid adhesive, or other suitable adhesive material. In the embodiment of  FIG. 8C , adhesive  848  is positioned within space  850  between trim  844  and enclosure portion  852 . The magnitude of space  850  depends on an offset of chamfer  853  of trim  844  and chamfer  855  of enclosure portion  852 . In one embodiment, chamfer  853  of trim  844  is larger than chamfer  855  of enclosure portion  852 . 
       FIG. 8D  shows sensor assembly  866  positioned within an opening of enclosure portion  872  of electronic device  860 . For simplicity, sensor assembly  866  and trim  864  are shown as a single block. Inset  862  shows a detailed view of an interface region between trim  864  and enclosure portion  872 . Gasket  868  is positioned on interior surfaces of trim  864  and enclosure portion  872 , and is configured to prevent moisture from entering between trim  864  and enclosure portion  872 . Gasket  868  can be composed of any suitable material, including one or more polymer materials, such as silicone. In some cases, gasket  868  is adhered to interior surfaces of trim  864  and/or enclosure portion  872  by an adhesive. In some embodiments, gasket  868  is composed of a waterproof plastic and is adhered to interior surfaces of trim  864  and enclosure portion  872  via a stack of adhesives. Since gasket  868  is accessible from the interior of the enclosure, this configuration allows gasket  868  to be assembled before or after assembling sensor assembly  866 . 
       FIG. 8E  shows sensor assembly  886  positioned within an opening of enclosure portion  892  of electronic device  880 . For simplicity, sensor assembly  886  and trim  884  are shown as a single block. Inset  882  shows a detailed view of an interface region between trim  884  and enclosure portion  892 . Potting  888  is positioned on interior surfaces of trim  884  and enclosure portion  892 , and is configured to prevent moisture from entering between trim  884  and enclosure portion  892 . Potting  888  can include one or more an adhesive material that is applied to interior surfaces of trim  864  and/or enclosure portion  872 . Potting  888  should be applied in a sufficiently flowable state such that portions of potting  888  flows between trim  864  and/or enclosure portion  872 . Once dried and hardened, potting  888  provides sufficient sealing. Potting  888  can be applied before or after assembling sensor assembly  886 . 
       FIGS. 9A-9C  show cross-section and top views of electronic device  900  having a trimless sensor assembly configuration, in accordance with some embodiments.  FIGS. 9A and 9B  show top views of a portion of electronic device  900  having sensor assembly  906 .  FIG. 9A  shows sensor assembly  906  with sensor cover  902 , and  FIG. 9B  shows sensor assembly  906  without sensor cover  202 .  FIG. 9C  shows cross-section view at B-B of  FIG. 9A . 
       FIG. 9A  shows that sensor cover  902  is adjacent to display cover  912  without a trim between them.  FIG. 9B  shows that sensor component  904  is positioned beneath sensor cover  902 . In some embodiments, sensor component  904  is a fingerprint sensor or touch sensor. Surrounding sensor component  904  is mounting ring  916 , which, in turn, is surrounded by compressible gasket  932 . 
       FIG. 9C  shows that sensor cover  902  is adjacent display cover  912  without a trim, and that display cover  912  is coupled to enclosure portion  910 . Mounting ring  916  supports sensor cover  902  and is positioned between sensor cover  902  and stiffener  905 . Sensor assembly  906  is coupled to display cover  912  by fastener  911 . In some embodiments, mounting ring  916  is composed of a conductive material (e.g., metal) that capacitively senses the presence of a finger at exterior surface  913  of sensor cover  902 . That is mounting ring  916  is configured to capacitively detect the presence of a finger through sensor cover  902 . 
     Compressible gasket  932  is positioned between sensor cover  902  and ledge  918  of display cover  912 . Compressible gasket  932  can be made of any suitable compressible material, including one or more polymers or adhesives. In some embodiments, compressible gasket  932  is composed of layers of compressible materials. Compressible gasket  932  can be in the form of a single piece or have multiple pieces. In some cases, compressible gasket  932  has a round ring shape that corresponds to a round shape of sensor cover  902 . When a user touches exterior surface  913  of sensor cover  902 , the thickness of compressible gasket  932  reduces in the sensing direction  903 . The force is transferred to first capacitive layer  922   a , thereby reducing a distance between first capacitive layer  922   a  and second capacitive layer  922   b . This, in turn, causes a change in voltage or capacitance of touch sensor  922 . Touch sensor  922  then generates a signal that activates one or more electrical circuits of electronic device  900 . Compressible gasket  932  is composed of a compliant material that provides a resistive force (opposite sensing direction  903 ) that returns sensor cover  902  back to its un-pressed position. Once sensor cover  902  is back in its un-pressed position, compressible gasket  932  returns to its full thickness. 
       FIGS. 10A-10D  show cross-section and top views of sensor assembly  1006  that is configured to vibrate, in accordance with some embodiments.  FIG. 10A  shows a top view of a portion of electronic device  1000  having sensor assembly  1006 .  FIG. 10B  shows cross-section view at C-C of  FIG. 10A .  FIG. 10C  shows cross-section view D-D of  FIG. 10B .  FIG. 10D  shows cross section view E-E of  FIG. 10B . 
       FIG. 10A  shows piezoelectric actuator  1001  is located adjacent to sensor assembly  1006 . Piezoelectric actuator  1001  is configured to vibrate sensor assembly  1006  in response to a user touching sensor cover  1002 .  FIG. 10B  shows that the perimeter of sensor cover  1002  is surrounded by movable trim  1008 , which is, in turn, surrounded by stationary trim  1004 . Movable trim  1008  can be composed of a compressible and compliant material, such as a compliant polymer (e.g., silicone). Stationary trim  1004  can be made of a relatively rigid material, such as metal. In some embodiments, stationary trim  1004  corresponds to a metal ring. In some cases, stationary trim  1004  has a chamfered edge that engages with a chamfered edge of display cover  1012 . 
     Seal  1011  is positioned between movable trim  1008  and stationary trim  1004 , and is configured to prevent entry of water or other liquid between movable trim  1008  and stationary trim  1004 . In some embodiments, seal  1011  is composed of a compressible material, such as a flexible polymer. The shape and size of seal  1011  will be in accordance with space limitations within sensor assembly  1006 . In some embodiments, seal  1011  has an O-ring shape. In some embodiments, movable trim  1008  has groove  1013  and stationary trim  1004  has groove  1018 , which accommodate seal  1011 . Sensor component  1014  can correspond to a portion of one or more sensors, such as a fingerprint sensor that detects features of a user&#39;s fingerprint and/or a touch sensor that detects a user&#39;s touch. 
     Display cover  1012  is supported by cover frame  1015 , which is, in turn, coupled to enclosure portion  1010 . In some embodiments, cover frame  1015  is composed of a reinforced glass fiber material, such as a glass-fiber reinforced with polyamide. Flange  1016  is positioned between display cover  1012  and cover frame  1015  and provides extra support for display cover  1012 . In some embodiments, flange  1016  is composed of a rigid metal, such a stainless steel. Retaining post  1017  is positioned below sensor component  1014 . Bracket  1019  supports stationary actuator beam  1020 , which is coupled to piezoelectric actuator  1001 . When sensor component  1014  detects a touch from a user, sensor component  1014  generates a signal that activates piezoelectric actuator  1001 . Piezoelectric actuator  1001  then causes portions of sensor assembly  1006  to move up and down (i.e., vibrate) along plane Z. For example, piezoelectric actuator  1001  can be configured to move sensor assembly  1006  such that a user feels sensor cover  1002  vibrate in response to the input. That is, sensor assembly  1006  can provide tactile feedback (output) that the user can feel, and that signals to the user that sensor assembly  1006  has been activated. 
     The cross-section view of  FIG. 10C  shows retaining post  1017  can be secured to bracket  1019  by retaining clip  1025 . Bracket  1019  is coupled to stationary trim  1004  via welds  1022 . Retaining post  1017  is coupled to and supports movable trim  1008 . The cross-section view of  FIG. 10D  shows that stationary actuator beam  1020  is held stationary by bracket  1019 . Flexure dome  1021 , which can be composed of resilient but stiff material (e.g., metal), is coupled one end to connector  1024  via weld  1026  and on another end to stationary actuator beam  1020  via weld  1030 . Connector  1024  is coupled to piezoelectric actuator  1001  (not shown). When sensor component  1014  detects an input, sensor component  1014  generates a signal that activates piezoelectric actuator  1001 . In response, piezoelectric actuator  1001  pushes connector  1024  in a push direction  1029 . Connector  1024  slides along stationary actuator beam  1020  and causes flexure dome  1021  to flex and push up on and release stiffener  1027 . Stiffener  1027  then causes movable trim  1008  compress and decompress, thereby causing sensor cover  1002  to move up and down (i.e., vibrate) along plane Z. 
       FIGS. 11A-11C  show cross-section views of sensor assemblies having different sensing configurations, in accordance with some embodiments. The embodiments in  FIGS. 11A-11C  include architectures that allow for detection of a force input in a less localized bases (i.e., not just directly underneath a sensor cover). 
       FIG. 11A  shows electronic device  1100 , which includes sensor assembly  1106 . Sensor assembly  1106  includes sensor cover  1102 , which is surrounded by trim  1104  and positioned with an opening within display cover  1112 . Display cover  1112  is coupled to enclosure portion  1110 . Bracket  1119  secures sensor assembly  1106  to enclosure portion  1110 . Fingerprint sensor  1105  is configured to recognize fingerprint features of a user through sensor cover  1102 . Sensor assembly  1106  has an active area-based force-sensing configuration. In particular, when a user touches or presses on sensor cover  1112 , the force will deflect display cover  1112 , thereby reducing distance  1108  between display cover  1112  and component  1114 . This activates force sensor  1118  (e.g., a flex capacitive sensor) that is positioned between display cover  1112  and component  1114 . This configuration allows for sensing in an area around sensor cover  1102 . 
       FIG. 11B  shows electronic device  1120 , which includes sensor assembly  1126 . Sensor assembly  1126  includes sensor cover  1122 , which is surrounded by trim  1124  and positioned with an opening within display cover  1132 . Display cover  1132  is coupled to enclosure portion  1130  (which includes enclosure sections  1130   a  and  1130   b ). Bracket  1139  secures sensor assembly  1126  to enclosure sections  1130   a  and  1130   b . Fingerprint sensor  1125  is configured to recognize fingerprint features of a user through sensor cover  1122 . Sensor assembly  1126  has a display cover-to-enclosure sensing configuration. In particular, when a user touches or presses on sensor cover  1122 , the force will deflect display cover  1132 , thereby reducing distance  1128  between bracket  1139  and enclosure section  1130   a . This activates force sensor  1129  (e.g., a flex capacitive sensor) that is positioned between bracket  1139  and enclosure section  1130   a.    
       FIG. 11C  shows electronic device  1140 , which includes sensor assembly  1146 . Sensor assembly  1146  includes sensor cover  1142 , which is surrounded by trim  1144  and positioned with an opening within display cover  1152 . Display cover  1152  is coupled to enclosure portion  1150 . Bracket  1159  secures sensor assembly  1146  to enclosure portion  1150 . Fingerprint sensor  1145  is configured to recognize fingerprint features of a user through sensor cover  1142 . Sensor assembly  1146  has an external module-based force-sensing configuration. In particular, when a user touches or presses on sensor cover  1142 , the force will deflect display cover  1132 , thereby reducing distance  1158  between sensory assembly  1146  and bracket  1159 . In some embodiments, distance  1158  is between stiffener  1148  of sensor assembly  1146  and bracket  1159 . This activates force sensor  1149  (e.g., a flex a capacitive sensor) that is positioned between sensory assembly  1146  and bracket  1159 . 
       FIG. 11D  shows a perspective view of bracket  1159 , which is incorporated within the sensor assembly  1146  configuration of  FIG. 11C , in accordance with some embodiments. Bracket  1159  includes relief cut  1155 , which can improve signal from small relative deflections of display cover  1152 . In some embodiments, bracket  1159  can include conductive portion  1153  (e.g., composed of metal) and non-conductive portion  1157  (e.g., plastic), which electrically isolates the conductive portion  1153 . As shown, non-conductive portion  1157  can include openings  1151  for fasteners (not shown). Bracket  1159  is shown as a single piece. However, in other embodiments, a bracket having multiple pieces is used. 
       FIGS. 12A and 12B  show cross-section views of a portion of an electronic device with sensor assembly  1206  before and during a bonding operation, respectively, in accordance with some embodiments.  FIG. 12A  shows sensor assembly  1206  prior to a bonding operation, where compliant member  1208  is positioned between sensor cover  1202  and trim  1204 . In some embodiments, compliant member  1208  includes one or more layers of compliant or resilient material, such a silicone or other polymer. As described above with compliant member  302  in  FIG. 3 , compliant member  1208  can be one piece or include separate pieces (e.g., four circle segment-shaped pieces to accommodate a rectangular-shaped sensor component). It should be noted, however, that compliant member  1208  can have any suitable shape and include any suitable number of pieces. Adhesive layer  1209   a  is applied between compliant member  1208  and sensor cover  1202 , and adhesive layer  1209   b  is applied between compliant member  1208  and ledge  1218  of trim  1204 , in order to secure compliant member  1208  to sensor cover  1202  and trim  1204 . Adhesive layers  1209   a  and  1209   b  can include any one or more suitable adhesive materials, such as layers of heat-activated film, pressure-sensitive adhesive, liquid adhesive, or other suitable adhesive material. 
       FIG. 12B  shows sensor assembly  1206  during a bonding operation, where a force is applied to sensor cover  1202  toward ledge  1218  of trim  1204 . As shown, if adhesive layers  1209   a  and  1209   b  are in liquid or semi-liquid form, adhesive layers  1209   a  and  1209   b  can cause overflow  1212  to form around the sides of compliant member  1208 . After adhesive layers  1209   a  and  1209   b  dry and harden, overflow  1212  can be stiffer than the material of compliant member  1208 , which may reduce the compliance of compliant member  1208 . 
       FIGS. 13A-13F  show sensor assembly configurations for preventing adhesive overflow  1212  from occurring.  FIG. 13A  shows a top view and a cross-section A-A view of a portion of an electronic device having sensor assembly  1306 . The top view shows sensor assembly  1306  without sensor cover  1302 , thereby exposing sensor component  1305  (e.g., fingerprint sensor). The cross-section A-A view shows that compliant member  1308  is positioned between sensor cover  1302  and ledge  1307  of trim  1304 . The thickness t 1  of adhesive layer  1309   a  and thickness t 2  of adhesive layer  1309   b  are each thin enough to eliminate or reduce the occurrence of overflow, yet are thick enough to adhere compliant member  1308  to sensor cover  1302  and trim  1304 . In some embodiments, the total thickness (t 1 +t 2 ) of adhesive layers  1309   a  and  1309   b  is about 20 micrometers. 
       FIG. 13B  shows a top view and a cross-section B-B view of a portion of an electronic device having sensor assembly  1316 . The top view shows sensor assembly  1316  without sensor cover  1312 , thereby exposing sensor component  1315  (e.g., fingerprint sensor). The cross-section B-B view shows compliant member  1318  positioned between sensor cover  1312  and ledge  1307  of trim  1314 . In this embodiment, the total thickness (t 3 +t 4 ) of adhesive layers  1319   a  and  1319   b , respectively, is larger than the total thickness (t 1 +t 2 ) of adhesive layers  1309   a  and  1309   b  described above with reference to  FIG. 13A . This greater amount of adhesive material can increase the bond strength of compliant member  1318  to sensor cover  1302  and trim  1304  compared to thinner adhesive layers. In some embodiments, the total thickness (t 3 +t 4 ) is about 20 micrometers. In some cases, however, these larger thicknesses t 3  and t 4  can increase the risk of overflow around the edges of compliant member  1318 , such as described above with reference to  FIG. 2B . 
       FIG. 13C  shows a top view and a cross-section C-C view of a portion of an electronic device having sensor assembly  1326 . The top view shows sensor assembly  1326  without sensor cover  1322 , thereby exposing sensor component  1325  (e.g., fingerprint sensor). The cross-section C-C view shows compliant member  1328  positioned between sensor cover  1322  and ledge  1327  of trim  1324 . Prior to applying a force during a bonding operation (e.g., see  FIG. 2B ), adhesive layer  1329   a  covers less surface area of compliant member  1328  and has lesser volume of adhesive material than adhesive layer  1329   b . This configuration can eliminate or reduce the amount of overflow at the top edges of compliant member  1328 . In particular, when a force is applied during a bonding operation, both adhesive layers  1329   a  and  1329   b  will spread toward the edges of compliant member  1328 . Since adhesive layer  1329   a  has a lesser volume, adhesive layer  1329   a  will not overflow or will overflow very little. This configuration can be useful in embodiments where less adhesive material is needed to adequately adhere compliant member  1328  to sensor cover  1322  compare to an amount of adhesive material needed to adequately adhere compliant member  1328  to trim  1324 . 
       FIG. 13D  shows a top view and a cross-section D-D view of a portion of an electronic device having sensor assembly  1336 . The top view shows sensor assembly without sensor cover  1332 , thereby exposing sensor component  1335  (e.g., fingerprint sensor). The cross-section D-D view shows compliant member  1338  positioned between sensor cover  1332  and ledge  1337  of trim  1334 . In this embodiment, both adhesive layers  1339   a  and  1339   b  cover less surface area of compliant member  1338  and have lesser volume of adhesive than the embodiment of  FIG. 3A  or  FIG. 3B . This configuration can eliminate or reduce the amount of overflow at the top and bottom edges of compliant member  1338  once a force is applied during a bonding operation (see  FIG. 2B ). Care should be taken, however, to assure that adhesive layers  1339   a  and  1339   b  have enough volume to adequately bond compliant member  1338  with sensor cover  1332  and trim  1334 . In some cases, this may mean increasing tolerances during the manufacturing process. 
       FIG. 13E  shows a top view and a cross-section E-E view of a portion of an electronic device having sensor assembly  1346 . The top view shows sensor assembly  1346  without sensor cover  1342 , thereby exposing sensor component  1345  (e.g., fingerprint sensor). The cross-section E-E view shows compliant member  1348  positioned between sensor cover  1342  and ledge  1347  of trim  1344 . In this embodiment, adhesive layers  1349   a  and  1349   b  are in a staggered configuration. In particular, adhesive layer  1349   a  is positioned closer to first end  1341  of compliant member  1348 , and adhesive layer  1349   b  is positioned closer to second end  1343  of compliant member  1348 . In some cases, adhesive layers  1349   a  and  1349   b  do not over lap at middle portion  1340  of compliant member  1348 . When a force is applied during a bonding operation, any overflow will be directed to opposing ends of compliant member  1348  (i.e., first end  1341  and second end  1343 ). This prevents joining of any of the overflow of adhesive layers  1349   a  and  1349   b  at the edges of compliant member  1348 . Note that care should be taken to assure that the load applied during the bonding operation is even despite the staggered adhesive layer configuration. 
       FIG. 13F  shows a top view and a cross-section F-F view of a portion of an electronic device having sensor assembly  1356 . The top view shows sensor assembly  1356  without sensor cover  1352 , thereby exposing sensor component  1355  (e.g., fingerprint sensor). The cross-section F-F view shows compliant member  1358  positioned between sensor cover  1352  and ledge  1357  of trim  1354 . In this embodiment, compliant member  1358  includes recesses  1353 , which correspond to channels that provide space for adhesive layer  1259   a  to flow into during the bonding operation (e.g., as shown in  FIG. 12B ), thereby preventing overflow of adhesive material around the outer edges of compliant member  1358 . Furthermore, this configuration can enhance an even distribution of adhesive layer  1259   a  at the surface of compliant member  1358 . Recesses  1353  can have any suitable shape and are not limited to the elongated channel shapes shown in  FIG. 13F . For example, the recesses can be circular, triangular, rectangular, and/or chevron shaped. In some embodiments, recesses are on an opposing side of compliant member  1358  in order to accommodate adhesive layer  1259   b . In some embodiments, two sides of compliant member  1358  include recesses in order to accommodate adhesive layer  1259   a  and adhesive layer  1259   b.    
     The foregoing description, for purposes of explanation, uses specific nomenclature to provide a thorough understanding of the described embodiments. However, it will be apparent to one skilled in the art that the specific details are not required in order to practice the described embodiments. Thus, the foregoing descriptions of the specific embodiments described herein are presented for purposes of illustration and description. They are not intended to be exhaustive or to limit the embodiments to the precise forms disclosed. It will be apparent to one of ordinary skill in the art that many modifications and variations are possible in view of the above teachings.

Metadata:
Filing Date: 20210304
Publication Date: 20220830
Grant Date: 20220830
Priority Date: 20160830
Inventors: BROWNING, LUCY ELIZABETH
POPE, BENJAMIN J.
LEUTHEUSER, PAUL U.
MYERS, SCOTT A.
DINH, RICHARD HUNG MINH
HUO, EDWARD S.
Assignee: APPLE INC
CPC Classifications: [{"code": "G06F3/016", "inventive": true, "first": false, "tree": "[]"}, {"code": "G06F2203/0338", "inventive": false, "first": false, "tree": "[]"}, {"code": "G06F1/1688", "inventive": true, "first": false, "tree": "[]"}, {"code": "G06F1/1684", "inventive": true, "first": false, "tree": "[]"}, {"code": "H03K17/964", "inventive": false, "first": false, "tree": "[]"}, {"code": "G06F1/169", "inventive": true, "first": true, "tree": "[]"}, {"code": "G06F3/165", "inventive": true, "first": false, "tree": "[]"}, {"code": "H03K17/975", "inventive": true, "first": false, "tree": "[]"}, {"code": "G06F1/1671", "inventive": true, "first": false, "tree": "[]"}, {"code": "G06F3/016", "inventive": true, "first": false, "tree": "[]"}, {"code": "G06F3/167", "inventive": false, "first": false, "tree": "[]"}, {"code": "H03K17/962", "inventive": true, "first": false, "tree": "[]"}, {"code": "G06F1/1626", "inventive": true, "first": false, "tree": "[]"}, {"code": "G06F3/167", "inventive": false, "first": false, "tree": "[]"}, {"code": "G06V40/1306", "inventive": true, "first": false, "tree": "[]"}, {"code": "G06F1/169", "inventive": true, "first": true, "tree": "[]"}, {"code": "G06F1/1684", "inventive": true, "first": false, "tree": "[]"}, {"code": "G06F1/1626", "inventive": true, "first": false, "tree": "[]"}, {"code": "G06V40/1306", "inventive": true, "first": false, "tree": "[]"}, {"code": "H03K17/962", "inventive": true, "first": false, "tree": "[]"}, {"code": "H03K17/975", "inventive": true, "first": false, "tree": "[]"}, {"code": "H03K17/964", "inventive": false, "first": false, "tree": "[]"}, {"code": "G06F1/1688", "inventive": true, "first": false, "tree": "[]"}, {"code": "G06F2203/0338", "inventive": false, "first": false, "tree": "[]"}, {"code": "G06F1/1671", "inventive": true, "first": false, "tree": "[]"}, {"code": "G06F1/1688", "inventive": true, "first": false, "tree": "[]"}, {"code": "H03K17/962", "inventive": true, "first": false, "tree": "[]"}, {"code": "G06F1/1684", "inventive": true, "first": false, "tree": "[]"}, {"code": "G06F1/169", "inventive": true, "first": true, "tree": "[]"}, {"code": "G06F2203/0338", "inventive": false, "first": false, "tree": "[]"}, {"code": "G06F1/1671", "inventive": true, "first": false, "tree": "[]"}, {"code": "H03K17/964", "inventive": false, "first": false, "tree": "[]"}, {"code": "G06V40/1306", "inventive": true, "first": false, "tree": "[]"}, {"code": "H03K17/975", "inventive": true, "first": false, "tree": "[]"}, {"code": "G06F3/165", "inventive": true, "first": false, "tree": "[]"}, {"code": "G06F3/167", "inventive": false, "first": false, "tree": "[]"}, {"code": "G06F3/016", "inventive": true, "first": false, "tree": "[]"}, {"code": "G06F1/1626", "inventive": true, "first": false, "tree": "[]"}, {"code": "G06F3/03547", "inventive": true, "first": false, "tree": "[]"}, {"code": "G06F1/1684", "inventive": true, "first": true, "tree": "[]"}, {"code": "H10N30/30", "inventive": true, "first": false, "tree": "[]"}, {"code": "G06F3/016", "inventive": true, "first": false, "tree": "[]"}]
Family ID: 60934987