PATENT DOCUMENT

Publication Number: US-9060111-B2
Application Number: US-201213605000-A
Country: US
Kind Code: B2

Title: Electronic device with compact camera module

Abstract:
A compact electronic device may include a camera module having an image sensor. The image sensor may be controlled by storage and processing circuitry to capture image data from received light. The camera module may include a substrate having front and rear surfaces. The image sensor may be mounted to the rear surface of the substrate. The substrate may include optical focusing structures on the front surface of the substrate that focus light through an opening in the substrate to the image sensor. A flex circuit may be used to convey signals between the camera module and other electronic device components. The flex circuit may be mounted to the front surface of the camera module substrate to help reduce total height of the camera module. The flex circuit may be mounted to an extended portion of the substrate or may be mounted to surround the periphery of the image sensor.

Claims:
What is claimed is: 
     
       1. A camera module, comprising:
 a substrate having front and rear surfaces and an opening that extends between the front and rear surfaces of the substrate; 
 an image sensor on the rear surface of the substrate, wherein the image sensor covers the opening in the substrate; and 
 a flexible printed circuit mounted to the front surface of the substrate. 
 
     
     
       2. The camera module defined in  claim 1  wherein the substrate includes a recess and wherein the image sensor is mounted to the substrate within the recess. 
     
     
       3. The camera module defined in  claim 2  further comprising:
 optical focusing structures having at least one lens on the front surface of the substrate, wherein optical focusing structures are configured to focus light onto the image sensor through the opening in the substrate. 
 
     
     
       4. The camera module defined in  claim 3  further comprising:
 a housing structure on the front surface of the substrate, wherein the housing structure surrounds the optical focusing structures and wherein the flexible printed circuit is wrapped around at least a portion of the housing structure. 
 
     
     
       5. The camera module defined in  claim 2  further comprising:
 a heat sink on the rear surface of the substrate that covers the image sensor and the recess. 
 
     
     
       6. The camera module defined in  claim 2  further comprising:
 an electromagnetic shielding layer on the rear surface of the substrate that covers the image sensor and the recess. 
 
     
     
       7. The camera module defined in  claim 2  further comprising:
 a shock absorber structure on the rear surface of the substrate that covers the image sensor and the recess. 
 
     
     
       8. The camera module defined in  claim 2  further comprising a rigid metal support structure that covers a portion of the flexible printed circuit. 
     
     
       9. The camera module defined in  claim 7  further comprising an electromagnetic shielding layer that covers a portion of the flexible printed circuit. 
     
     
       10. The camera module defined in  claim 1  wherein the substrate comprises a ceramic substrate. 
     
     
       11. The camera module defined in  claim 1  wherein the substrate includes traces that electrically couple the flexible printed circuit to the image sensor through the substrate. 
     
     
       12. The camera module defined in  claim 1  wherein the flexible printed circuit is attached to the front surface of the substrate by anisotropic conductive film. 
     
     
       13. The camera module defined in  claim 1  further comprising:
 a surface-mount technology electrical component mounted to the front surface of the substrate. 
 
     
     
       14. The camera module defined in  claim 1  wherein the flexible printed circuit surrounds the opening in the substrate. 
     
     
       15. An electronic device comprising:
 an electronic device housing having a transparent window; 
 a substrate; 
 optical focusing structures mounted to the substrate; 
 a flexible printed circuit mounted to the substrate adjacent to the optical focusing structures, wherein the substrate has front and rear surfaces, wherein the optical focusing structures and the flexible printed circuit are mounted to the front surface of the substrate, and wherein the front surface of the substrate faces the transparent window; 
 an image sensor mounted to the rear surface of the substrate, wherein the substrate includes a central portion having a recess and an extended portion, wherein the image sensor is mounted to the substrate within the recess of the central portion of the substrate and wherein the flexible printed circuit is mounted to the extended portion of the substrate. 
 
     
     
       16. The electronic device defined in  claim 15  wherein the substrate comprises a ceramic substrate, the electronic device further comprising:
 a printed circuit board, wherein the flexible printed circuit is connected to the printed circuit board; and 
 control circuitry on the printed circuit board, wherein the flexible printed circuit conveys control and data signals between the image sensor and the control circuitry. 
 
     
     
       17. The electronic device defined in  claim 15  wherein the substrate includes an opening that extends between the front and rear surfaces of the substrate, wherein the optical focusing structures are mounted on the front surface of the substrate between the transparent window and the opening in the substrate, wherein the image sensor is mounted on the rear surface of the substrate over the opening and wherein the optical focusing structures are configured to focus light from the transparent window onto the image sensor through the opening in the substrate. 
     
     
       18. The electronic device defined in  claim 15  wherein the substrate comprises a high temperature co-fired ceramic substrate. 
     
     
       19. An electronic device camera module, comprising:
 a substrate having opposing first and second surfaces; 
 a flexible printed circuit mounted to the first surface of the substrate; 
 an image sensor mounted to the second surface of the substrate; and 
 a protective structure mounted to the second surface of the substrate, wherein the protective structure covers and surrounds the image sensor. 
 
     
     
       20. The electronic device camera module defined in  claim 19  wherein the substrate has uniform thickness. 
     
     
       21. The electronic device camera module defined in  claim 20  wherein the protective structure is separated from the image sensor by a gap, the electronic device camera module further comprising:
 thermally conductive material that fills the gap between the protective structure and the image sensor. 
 
     
     
       22. The electronic device camera module defined in  claim 19  wherein the substrate includes traces that convey image data signals and control signals between the flexible printed circuit and the image sensor.

Description:
BACKGROUND 
     This relates generally to electronic devices, and more particularly, electronic devices having camera modules with image sensors. 
     Electronic devices such as portable computers, tablet computers, and cellular telephones are often provided with camera modules. The camera modules include digital image sensors and additional structures such as a lens and autofocus structures. A digital image sensor is typically mounted to a camera module substrate. 
     It may be challenging to provide camera modules that are sufficiently slim. For example, signal routing structures for conveying captured image signals from the image sensor are often mounted to the underside of a camera module substrate. The signal routing structures may add undesired size to an electronic device. Particularly in compact devices such as cellular telephones, tablet computers, portable computers, and other such electronic devices in which space is at a premium, it may not be acceptable to use bulky conventional camera modules. 
     It would therefore be desirable to be able to provide improved ways of forming camera modules in electronic devices. 
     SUMMARY 
     A compact electronic device may include an electronic device housing. The electronic device housing may enclose components such as storage and processing circuitry and a camera module. The storage and processing circuitry may be formed on a printed circuit substrate. The camera module may include an image sensor that receives light through a transparent window in the electronic device housing. The image sensor may be controlled by the storage and processing circuitry to capture image data from the received light. 
     The camera module may include a camera module substrate having front and rear surfaces. The camera module substrate may be a ceramic substrate such as a high temperature co-fired ceramic substrate. The image sensor may be mounted to the rear surface of the camera module substrate (e.g., the image sensor may be a flip-chip integrated circuit or a packaged integrated circuit that is attached to the rear surface of the camera module substrate). As an example, the image sensor may be mounted within a recess of the camera module substrate. The camera module substrate may include an opening through which light received from the transparent window is passed to the image sensor. The camera module may include optical focusing structures mounted on the camera module substrate between the opening in the camera module substrate and the transparent window. The optical focusing structures may include one or more lenses that focus received light onto the image sensor. 
     A flex circuit may be used to convey image data signals and control signals between the camera module and other components such as the storage and processing circuitry. The flex circuit may be mounted to the front surface of the camera module substrate to help reduce total height of the camera module. The flex circuit may be mounted to an extended portion of the camera module substrate or may be mounted to surround the periphery of the image sensor and the optical focusing structures. Traces on the camera module substrate may electrically couple the flex circuit to the image sensor and/or the optical focusing structures. 
     Further features of the invention, its nature and various advantages will be more apparent from the accompanying drawings and the following detailed description of the preferred embodiments. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a front perspective view of an illustrative electronic device of the type that may include a camera module having a digital image sensor in accordance with an embodiment of the present invention. 
         FIG. 2  is a rear perspective view of an illustrative electronic device of the type that may include a camera module having a digital image sensor in accordance with an embodiment of the present invention. 
         FIG. 3  is a cross-sectional side view of an illustrative electronic device containing a camera module having a digital image sensor in accordance with the present invention. 
         FIG. 4  is a schematic diagram of an illustrative electronic device having a camera module in accordance with an embodiment of the present invention. 
         FIG. 5  is a cross-sectional side view of an illustrative camera module having an image sensor and a flex circuit mounted to a substrate in accordance with the present invention. 
         FIG. 6  is an illustrative perspective view of a flex circuit mounted on an extended portion of a camera module substrate in accordance with the present invention. 
         FIG. 7  is a perspective view of an illustrative camera module having a flex circuit that is wrapped around an optical housing structure in accordance with the present invention. 
         FIG. 8A  is an illustrative perspective view of a flex circuit that is mounted to a substrate and surrounds the periphery of an image sensor in accordance with the present invention. 
         FIG. 8B  is an illustrative perspective view of a flex circuit that is mounted to a substrate and surrounds the periphery of an optical housing structure that covers an image sensor in accordance with the present invention. 
         FIG. 9  is an cross-sectional view of an illustrative camera module having a flex circuit and an image sensor mounted to a substrate of uniform thickness in accordance with the present invention. 
     
    
    
     DETAILED DESCRIPTION 
     Electronic devices such as electronic device  10  of  FIG. 1  may be provided with camera systems. Digital images may be captured using a camera module having an image sensor. There may be any suitable number of camera modules in device  10 . For example, there may be one camera module in the camera systems of device  10 , there may be two camera modules in device  10 , or there may be three or more camera modules in device  10  (as examples). 
     Device  10  of  FIG. 1  may be portable electronic equipment such as a cellular telephone, a tablet computer, a media player, a wrist-watch device, a pendant device, an earpiece device, a notebook computer, other compact portable devices, or other electronic equipment such as a computer monitor with an integrated computer, a desktop computer, or a television. 
     Device  10  of  FIG. 1  may include a housing such as housing  12 . Housing  12 , which may sometimes be referred to as a case or an electronic device housing, may be formed of plastic, glass, ceramics, fiber composites, metal (e.g., stainless steel, aluminum, etc.), other suitable materials, or a combination of these materials. Housing  12  may be formed from a unibody structure (e.g., a structure that is machined from a single piece of material) or may include internal frame structures and exterior wall structures (as examples). Other types of housing construction may also be used if desired. 
     Device  10  may, if desired, have a display such as display  14 . Display  14  may be a touch screen that incorporates touch sensitive structures such as capacitive touch electrodes or display  14  may be touch insensitive. Display  14  may include image pixels formed from light-emitting diodes (LEDs), organic LEDs (OLEDs), plasma cells, electrophoretic display elements, electrowetting display elements, liquid crystal display (LCD) components, or other suitable image pixel structures. A cover layer such as a layer of glass or clear plastic may cover the surface of display  14 . Buttons and speaker port openings may pass through openings in the cover glass. For example, the cover layer for display  14  may have an opening for a front-facing button such as button  16  and a speaker opening such as speaker port opening  18 . 
     Portions of display  14  may form active regions (i.e., regions in which the image pixels of display  14  form images for a user). Portions of display  14  may also form inactive regions (e.g., peripheral portions of display  14  that to not have any active image pixels). Camera window structures such as camera window structure  20  may be provided in the cover layer for display  14  (e.g., to form a front-facing camera). The camera windows structures may be formed from transparent materials such as glass, plastic, or other transparent materials. Camera window  20  of  FIG. 1  may, for example, be formed in an inactive portion of display  14 . The display cover layer in the inactive portion of display  14  may be provided with an opaque masking layer such as a layer of black ink. Camera window  20  may be formed from an opening in the opaque masking layer. 
     If desired, camera windows  20  may be formed elsewhere in device housing  12 . As shown in the rear perspective view of device  10  of  FIG. 2 , camera window  20  may be formed on the rear surface of housing  12  (e.g., to form a rear-facing camera). 
       FIG. 3  is a cross-sectional side view of electronic device  10 . As shown in  FIG. 3 , camera module  24  may include optical structures  26  and digital image sensor  28 . Optical structures  26  may include lens structures (e.g., one or more lenses), focusing structures such as auto-focusing structures, filters such as infrared filters, or other optical structures. Optical structures  26  may have actuators that assist in optical focus adjustments (e.g., voice coil motors (VCMs), piezoelectric motors, direct-current motors, or other actuators). Image light  32  may pass through transparent camera window  20  in housing  12  (e.g., the display cover layer, a rear housing surface, or other portions of device  10 ). The received image light may be focused by optical structures  26  onto digital image sensor  28  in camera  24 . Digital image sensor  28  may be a complementary metal-oxide-semiconductor (CMOS) sensor, a charge-coupled device (CCD) sensor, or other suitable image sensor capable of capturing digital images for device  10 . 
     Device  10  may include control circuitry such as one or more microprocessors, digital signal processors, system-on-chip circuits, microcontrollers, application-specific integrated circuits, memory chips, solid state drives, removable memory devices, volatile memory circuits, non-volatile memory circuits, hard disk drives, etc. As shown in  FIG. 3 , control circuitry may be implemented using one or more electrical components  30  mounted to one or more substrates such as substrate  22 . If desired, portions of the control circuitry may be formed as part of camera module  24 . Components  30  may include integrated circuits, discrete components, sensors, connectors, battery structures, status indicator lights (e.g., light-emitting diodes), displays, input-output components, wired and wireless communications circuitry, etc. Substrate  22  may be a rigid printed circuit board (e.g., a fiberglass-filled epoxy board), a flexible printed circuit (e.g., a “flex circuit” formed from conductive traces on a flexible sheet of polymer such as polyimide), other dielectric structures, or other suitable substrate materials. 
     Components  30  (e.g., control circuitry) may be coupled to camera module  24  via paths  40 . Paths  40  may, for example, include traces formed on a flex circuit. For example, the flex circuit may include traces formed on a flexible sheet of polymer such as polyimide (e.g., a flexible polyimide substrate). In this scenario, the traces may be used to convey image data and control signals between camera module  24  and components  30 . The flex circuit may be connected to substrate  22  via a connector, by mounting the flex circuit directly to traces on substrate  22 , or using desired connections. 
     Space may be at a premium in compact devices, so it may be desirable to form camera module  22  using a compact camera structure. As shown in  FIG. 3 , for example, the vertical separation T between upper and lower housing surfaces may constrain the dimensions of camera module  22 . It may be challenging to provide camera modules  26  having sufficient performance when constrained by available space in compact devices. For example, optical structures  26  that are reduced in size to accommodate space constraints may provide poor optical performance. 
     A schematic diagram of an illustrative electronic device  10  having a camera module  24  is shown in  FIG. 4 . Camera module  24  may include optical structures  26  such as a lens, autofocus structures, filter structures, or other structures such as actuators, etc. Optical structures  26  may include one or more image sensors  28  and other components  34  such as discrete components (e.g., resistors, capacitors, etc.) or integrated circuits (e.g., driver circuits, processing circuits, etc.). 
     Electronic device  10  may include control circuitry such as storage and processing circuitry  38 . Storage and processing circuitry  38  may include storage such as hard disk drive storage, nonvolatile memory (e.g., flash memory or other electrically-programmable-read-only memory configured to form a solid state drive), volatile memory (e.g., static or dynamic random-access-memory), etc. Processing circuitry in storage and processing circuitry  38  may be used to control the operation of device  10 . This processing circuitry may be based on one or more microprocessors, microcontrollers, digital signal processors, baseband processors, power management units, audio codec chips, application specific integrated circuits, etc. 
     Storage and processing circuitry  38  may be used to run software on device  10 , such as image capture functions, internet browsing applications, voice-over-internet-protocol (VoIP) telephone call applications, email applications, media playback applications, operating system functions, etc. For example, storage and processing circuitry  38  may be used to perform image capture functions using camera module  24 . In this scenario, storage and processing circuitry  38  may provide control signals to camera module  24  via paths  40  (e.g., paths on a flex circuit) that direct camera module  24  to capture an image using image sensor  28  and optical structures  26 . Camera module  24  may subsequently provide captured image data to storage and processing circuitry  38  via paths  40 . If desired, power may also be provided to camera module  24  via paths  40 . 
     Input-output circuitry  36  may be used to allow data to be supplied to device  10  and to allow data to be provided from device  10  to external devices. Input-output circuitry  36  may include input-output devices such as camera module  24 , display  14 , buttons, joysticks, click wheels, scrolling wheels, touch pads, key pads, keyboards, microphones, speakers, tone generators, vibrators, sensors, light-emitting diodes and other status indicators, data ports, etc. A user can control the operation of device  10  by supplying commands through input-output circuitry  36  and may receive status information and other output from device  10  using the output resources of input-output devices  36 . 
       FIG. 5  is an illustrative cross-sectional diagram of a compact camera module  24 . Camera module  24  may include optical structures  26  (e.g., optical focusing structures), image sensor  28 , and one or more components  34  on substrate  60 . Substrate  60  may be formed from ceramic materials and may be formed having one or more layers. For example, substrate  60  may be a high temperature co-fired ceramic (HTCC) substrate having multiple layers formed from ceramic materials such as alumina oxide. This example is merely illustrative. If desired, substrate  60  may be formed from any desired printed circuit substrate materials. 
     Optical structures  26  may include an optical stack  52  and corresponding optical adjustment structures  54 . Optical stack  52  may include one or more lenses and may include optical focusing structures such as auto-focusing structures. Optical adjustment structures  54  may be used to adjust the focusing structures. For example, optical adjustment structures  54  may include actuators (e.g., magnetically driven linear motors such as voice coil motors or other motors) that are coupled to the focusing structures via springs. Optical adjustment structures  54  may include stabilizing structures such as shock absorbers. As examples, stabilizing structures may be formed from silicone, foam, or any desired elastomeric members to help stabilize optical stack  52  during image capture operations. 
     Optical structures  26  may include one or more filters such as filter  56 . Filter  56  may be formed from glass or other transparent materials and may be used to filter undesired portions of incoming light that is received by optical stack  52 . For example, filter  56  may be an infrared filter that removes infrared portions of incoming light while passing visible light (e.g., filter  56  may block light having wavelengths belonging to the infrared spectrum and pass light of the visible spectrum). 
     Optical structures  26  may be mounted over an opening  58  in substrate  60  for image sensor  28 . Opening  58  may, for example, be an air-filled gap in substrate  60 . Optical structures  26  may be mounted to substrate  60  over opening  58  via connections  66 . Connections  66  may, for example, be formed from adhesives such as glue, polymer-based adhesives, heat-cured adhesives, or other desired adhesive materials that help seal opening  58  (e.g., from external dust particles). 
     Substrate  60  may include a recess  64  for accommodating image sensor  28 . Image sensor  28  may be mounted to substrate  60  within recess  64  via connections  68 . Connections  68  may be formed using flip-chip techniques or other desired integrated circuit mounting techniques (e.g., ultrasonic bonding). For example, connections  68  may be formed from conductive material that couples opposing conductive pads  67  on substrate  60  and image sensor  28 . The conductive material and conductive pads may be formed from gold, copper, or other desired conductive materials. Connections  68  may include filler materials such as glue, liquid adhesives, heat-cured adhesives, or other desired adhesive materials. For example, insulating materials may be deposited to surround the conductive material of connections  68  so that opening  58  is sealed from external dust particles or other potentially damaging materials (e.g., to help prevent damage to image sensor  68 ). 
     Camera module  24  may include one or more components such as component  34  on substrate  60 . Component  34  may, for example, be a surface-mount technology (SMT) component that is mounted to substrate  60 . If desired, component  34  may include circuitry such as control circuitry or signal processing circuitry that is used to process signals associated with image sensor  28 . Component  34  may be an integrated circuit component or may be a discrete component such as a resistor, capacitor, inductor, etc. Camera module  24  may include one component  34 , two components  34 , three components  34  or more. 
     Substrate  60  may include traces  70  that provide signal paths for image sensor  28 , optical structures  26 , flex circuit  62 , and other components such as component  34 . Traces  70  may be formed from conductive materials deposited on the surface of substrate  60  or on intermediate layers of substrate  60 . For example, traces  70  may be formed from metals such as tungsten, copper, or other desired conductive materials. If desired, traces  70  may be coated with materials such as nickel. 
     Traces  70  may be used to convey signals between image sensor  28 , optical structures  26 , flex circuit  62 , and component  34 . For example, control signals may be provided to image sensor  28  from flex circuit  62  (e.g., from paths  40 ) via traces  70 , pads  67 , and connections  68 . In this scenario, the control signals may direct image sensor  28  to capture an image from light focused on image sensor  28  by optical structures  26 . Additional control signals may be provided via traces  70  to control optical adjustment structures  54  (e.g., from control circuitry in components such as component  34  or from flex circuit  62 ). The additional control signals may adjust the optical adjustment structures and optical stack to a desired configuration for focusing light onto image sensor  28 . Traces  70  may subsequently be used to provide digital image data captured from the focused light by image sensor  28  to component  34  for signal processing or directly to flex circuit  62 . 
     The vertical distance between image sensor  28  and the upper surface of optical stack  52  may be determined by optical design constraints and may sometimes be referred to as total track length (TTL). For example, optical design constraints may require that vertical distance TTL be 4.8 mm or 5.3 mm to provide satisfactory performance at focal distances greater than 10 cm. This example is merely illustrative. Optical design constraints may vary based on a desired performance level of camera module  24  (e.g., based on desired focal distances, desired image quality levels, etc.). To help accommodate optical design constraints in a compact electronic device, substrate  60  may be formed with an extended portion  72  to which flex circuit  62  is mounted. 
     Substrate  60  (e.g., a camera module substrate) may include opposing surfaces  77  (e.g., a front surface) and  79  (e.g., a rear surface). Front surface  77  of substrate  60  may face a camera window such as window  20  ( FIG. 3 ). Flex circuit  62  may be mounted to front surface  77  of extended portion  72  of substrate  60  via connection  74 . Connection  74  may include conductive materials that couple paths  40  of flex circuit  62  to traces  70  of substrate  60 . For example, connection  74  may include conductive adhesive such as an anisotropic conductive film, conductive epoxy, etc., or a conductive connection formed from thermosonic bonding. 
     By mounting flex circuit  62  to front surface  77  of extended portion  72  of substrate  60  (e.g., instead of on a rear surface of substrate  60  underneath image sensor  28 ), total height H of camera module  24  may be reduced. In other words, total height H of camera module  24  may be independent of the thickness associated with flex circuit  62  that is mounted on front surface  77  of substrate  60 . By forming camera modules  24  having reduced height H, electronic device thickness T ( FIG. 3 ) may be reduced while maintaining optical performance (e.g., because total track length TTL of camera module  26  is maintained). Alternatively, optical performance may be improved by increasing total track length TTL of optical structures  26  while maintaining thickness T of electronic device  10 . 
     If desired, an optional conductive layer  76  may cover a portion of flex circuit  62 . Conductive layer  76  may be formed from metals or other conductive materials and may be attached to flex circuit  62  via thermal bonding film, epoxy, or other adhesive materials. Conductive layer  76  may be a rigid layer that helps to protect the portion of flex circuit  62  that is coupled to substrate  60 . For example, conductive layer  76  may be formed from a rigid metal sheet that provides structural support for flex circuit  62 . If desired, conductive layer  76  may serve as a ground plane for flex circuit  62 , as an electromagnetic shielding layer, and/or as a heat sink. For example, conductive layer  76  may serve as a shielding layer that helps to protect connection  74  and traces  40  and  70  from electromagnetic interference (e.g., electromagnetic interference generated from external circuitry such as components  30  of device  10 ). As another example, conductive layer  76  may serve as heat sink structure that tends to spread heat away from potentially heat-producing structures such as connections  74 . If desired, multiple layers  76  may be formed. For example, a heat sink structure may be combined with a shielding structure and/or a ground plane structure. 
     Circuitry such as image sensor  28  tends to produce heat during normal operation (e.g., during image capture operations). By forming flex circuit on extended portion  72  of substrate  60 , image sensor  28  and recess  64  of substrate  60  may be exposed and heat radiating from image sensor  28  may be conducted away from sensor  28 . If desired, optional structures  78  such as a heat sink or heat spreader structure may be used to cover recess  64  and help maintain image sensor  28  at desired operating temperatures. For example, a heat sink formed from metal or other thermally conductive materials may be used to cover recess  64 . Optional structures  78  may include an electromagnetic shielding layer (e.g., a shielding layer formed from conductive materials) for shielding image sensor  28 . Optional structures  78  may include shock absorbing structures such as foam, silicone, or other elastomeric structures that help to stabilize camera module  24 . If desired, optional structures  78  may include any desired combination of shielding structures, shock absorbing structures, and heat sink structures. For example, a heat sink structure covering image sensor  28  may be attached to rear surface  72  of substrate  60  and covered with a shielding layer of metal and a layer of foam. 
       FIG. 6  is a perspective view of substrate  60  having an extended portion  72  to which flex circuit  62  is mounted. Image sensor  28  may be mounted in a recess within central portion  82  of substrate  60 . Components  34  may be mounted on central portion  82  or, if desired, on portion  72  of substrate  60 . In the example of  FIG. 6 , flex circuit  62  covers part of extended portion  72 . However, flex circuit  62  may be configured to cover all of extended portion  72  or may cover some of portion  82  of substrate  60  (if desired). 
     As shown in  FIG. 7 , camera module  26  may include a housing  84 . Housing  84  may cover and surround optical structures  26  and/or components  34  ( FIG. 5 ). Housing  84  may include an opening that accommodates optical stack  52  (e.g., so that light may reach image sensor  28  through optical stack  52 ). Housing  84  may be formed from any desired housing materials similar to electronic device housing  12 . Flex circuit  62  may be wrapped around housing  84  and coupled to other components of electronic device  10  to provide a slim profile. Flex circuit  62  that is wrapped around camera module  84  may sometimes be referred to herein as a wrapped flex circuit and may help to help reduce the overall dimensions of camera module  26 . 
     If desired, flex circuit  62  may be coupled to substrate  60  along the periphery of image sensor  28  as shown in  FIG. 8A . In the example of  FIG. 8A , flex circuit  62  may include an opening  92  that surrounds image sensor  28 . Flex circuit  62  may be coupled to substrate  60  along the periphery of opening  92  via connections similar to connections  74  of  FIG. 5  (e.g., anisotropic conductive film, conductive adhesives, etc.). For example, traces  40  on flex circuit  62  may be coupled to corresponding traces on substrate  60  such as traces  70  ( FIG. 5 ) along the periphery of opening  92  using anisotropic conductive film. By forming a flex circuit  62  that surrounds image sensor  28 , the footprint of camera module  26  may be reduced (e.g., because it may not be necessary to form substrate  60  having an extended portion). 
       FIG. 8B  is a perspective view of camera module  26  having flex circuit  62  with an opening such as opening  92  of  FIG. 8A . As shown in  FIG. 8B , the opening in flex circuit  62  may accommodate housing  84  and optical stack  52 . Flex circuit  62  may extend and couple to other components of electronic device  10 . 
     It may be challenging to form recesses in a camera module substrate for accommodating image sensors. For example, recess  64  of substrate  60  as shown in  FIG. 5  may add cost and complexity to substrate manufacturing processes. By attaching flex circuit  62  to a front surface of camera module substrate  60 , substrate  60  may be formed without an image sensor recess (e.g., as a uniform planar substrate).  FIG. 9  is a cross-sectional view of an illustrative camera module  24  having substrate  60  of uniform thickness X. As shown in  FIG. 9 , image sensor  28  may be mounted to substrate  60  over opening  58  (e.g., similarly to image sensor  28  of  FIG. 5 ). 
     Protective structure  102  may cover image sensor  28  and help to protect image sensor  28  (e.g., from accidental contact that may damage image sensor  28 ). Protective structure  102  may be formed from any desired material such as plastic or metal. Protective structure  102  may be attached to substrate  60  via adhesive  106  (e.g., glue, liquid adhesive, heat-cured adhesive, etc.). 
     Gap  104  may separate protective structures  106  from image sensor  28 . Gap  104  may be an air-filled gap. If desired, gap  104  may be filled with thermally conductive materials or other materials. Thermally conductive materials used to fill gap  104  may include thermally conductive plastics or other thermally conductive materials that help to draw heat away from image sensor  28 . 
     The foregoing is merely illustrative of the principles of this invention and various modifications can be made by those skilled in the art without departing from the scope and spirit of the invention. Any of the foregoing embodiments may be used alone or in combination with one or more of any of the other foregoing embodiments.

Metadata:
Filing Date: 20120906
Publication Date: 20150616
Grant Date: 20150616
Priority Date: 20120906
Inventors: SHUKLA ASHUTOSH Y.
WILLIAMS KENTA K.
WEBSTER STEVEN
Assignee: APPLE INC
CPC Classifications: [{"code": "H04N23/57", "inventive": true, "first": true, "tree": "[]"}, {"code": "H04N23/57", "inventive": true, "first": true, "tree": "[]"}, {"code": "H04N5/2257", "inventive": true, "first": false, "tree": "[]"}, {"code": "H04N5/2254", "inventive": true, "first": true, "tree": "[]"}]
Family ID: 50187067