PATENT DOCUMENT

Publication Number: US-8457333-B2
Application Number: US-201213401729-A
Country: US
Kind Code: B2

Title: Electromagnetic interference shields with piezos

Abstract:
Methods and apparatus for improving the acoustical performance associated with a speaker, such as a piezoelectric speaker, are disclosed. According to one aspect, an apparatus includes a substrate, a can mounted on the substrate, and a piezoelectric speaker arrangement. The piezoelectric speaker arrangement is at least partially mounted on the can. In one embodiment, the substrate is a printed circuit board (PCB) and the can is an electromagnetic interference (EMI) shielding can.

Claims:
What is claimed is: 
     
       1. An electronic device comprising:
 an electronic device housing; 
 a printed circuit board (PCB); 
 a component, the component being mounted on the PCB and substantially enclosing a first volume of air; 
 an audio exit opening arranged through a surface of the electronic device housing; 
 an audio seal enclosing a second volume of air within the electronic device housing, the second volume of air in direct contact with the component and the audio exit opening; and 
 a speaker mounted on a surface of the component so that the first volume of air enclosed by the component serves as a back volume and the second volume of air serves as a front volume, the two volumes of air operative to enhance sound waves produced by the speaker. 
 
     
     
       2. An electronic device of  claim 1 , wherein the audio exit opening is also an opening for an electrical connector. 
     
     
       3. The electronic device of  claim 1 , wherein the speaker includes at least a diaphragm element arranged to vibrate when producing sound. 
     
     
       4. The electronic device of  claim 1 , wherein the surface of the component includes at least one opening, and wherein the speaker is at least partially mounted on the surface of the component over the at least one opening. 
     
     
       5. An electronic device comprising:
 a printed circuit board (PCB); 
 at least one electrical component, the at least one electrical component being mounted on the PCB; 
 an electromagnetic interference (EMI) shield, the EMI shield being mounted directly to the PCB over and around the at least one electrical component and a first volume of air; 
 a second volume of air sealed within a portion of the electronic device, the second volume of air contained proximate to the EMI shield; 
 an audio exit opening configured to port audio out of the electronic device; and 
 a speaker mounted on an exterior surface of the EMI shield so that the first volume of air enclosed by the EMI shield serves as a back volume and the second volume of air serves as a front volume, the first and second volumes of air operative to enhance sound waves produced by the speaker. 
 
     
     
       6. The electronic device of  claim 5 , wherein the audio exit opening is also an opening for an electrical connector. 
     
     
       7. The electronic device of  claim 5 , wherein the speaker includes at least a diaphragm element arranged to vibrate when producing sound. 
     
     
       8. The electronic device of  claim 5 , wherein the first volume of air within the EMI shield is substantially sealed such that the first volume of air is confined within the EMI shield. 
     
     
       9. The electronic device of  claim 5 , further comprising:
 an electronic device housing; and 
 at least one seal configured to confine the second volume of air within the portion of the electronic device, 
 wherein the second volume of air is arranged within the electronic device housing and in direct contact with the audio exit opening. 
 
     
     
       10. The electronic device of  claim 5 , wherein the EMI shield is arranged to amplify sound associated with the speaker. 
     
     
       11. The electronic device of  claim 5 , wherein the speaker comprises a piezoelectric speaker. 
     
     
       12. The electronic device of  claim 5 , wherein the EMI shield includes a recess area at a portion of the surface, and wherein the speaker is mounted on the surface of the EMI shield at the recess area. 
     
     
       13. The electronic device of  claim 5 , wherein the EMI shield includes a recess area at a portion of the surface, and wherein the speaker is mounted on the surface of the EMI shield in the recess area. 
     
     
       14. The electronic device of  claim 5 , wherein the EMI shield includes a recess area at a portion of the surface, and wherein the speaker is mounted on the surface of the EMI shield over the recess area. 
     
     
       15. The electronic device of  claim 5 , wherein the speaker includes at least a diaphragm element arranged to vibrate when producing sound, and wherein a support member holds the diaphragm element to the EMI shield. 
     
     
       16. The electronic device of  claim 9 , wherein a first end of the at least one seal is coupled to inner surface of the electronic device housing and a second end of the at least one seal is coupled directly to the speaker. 
     
     
       17. The electronic device of  claim 9 , wherein the EMI shield can includes a top surface, wherein the top surface includes at least one opening, and wherein the speaker arrangement is at least partially mounted on the top surface over the at least one opening. 
     
     
       18. The electronic device of  claim 17 , wherein a first end of the at least one seal is coupled to an inner surface of the electronic device housing and a second end of the at least one seal is coupled directly to the speaker. 
     
     
       19. The electronic device of  claim 17 , wherein the EMI shield includes a recess area at a portion of the top surface, and wherein the speaker is mounted on the surface of the EMI shield at the recess area. 
     
     
       20. The electronic device of  claim 19 , wherein a first end of the at least one seal is coupled to an inner surface of the electronic device housing and a second end of the at least one seal is coupled directly to the speaker. 
     
     
       21. An audio system disposed within an enclosure, the audio system comprising:
 a printed circuit board (PCB); 
 an electromagnetic interference (EMI) shield coupled directly to the PCB and surrounding a first volume of air; 
 a speaker coupled to an exterior surface of the EMI shield; 
 a seal confining a second volume of air within a portion of the enclosure such that the second volume of air is in contact with the exterior surface of the EMI shield, 
 wherein the first and second volumes of air act respectively as back and front volumes of air for the speaker, the front and back volumes of air operative to enhance sound waves produced by the speaker. 
 
     
     
       22. The audio system as recited in  claim 21 , wherein an audio exit opening is disposed through a surface of the enclosure and configured to port audio out of the enclosure. 
     
     
       23. The audio system as recited in  claim 22 , wherein an opening in the EMI shield is in contact with a surface of the speaker that is in direct contact with the EMI shield.

Description:
CROSS-REFERENCE TO OTHER APPLICATIONS 
     This application is a continuation of U.S. patent application Ser. No. 12/236,452, filed Sep. 23, 2008, now U.S. Pat. No. 8,126,170 entitled “ELECTROMAGNETIC INTERFERENCE SHIELDS WITH PIEZOS”, which is hereby incorporated herein by reference, and which in turn claims priority to U.S. Provisional Patent Application No. 61/094,811, filed Sep. 5, 2008, entitled “ELECTROMAGNETIC INTERFERENCE SHIELDS WITH PIEZOS”, which is hereby incorporated herein by reference. 
     This application also references U.S. Provisional Patent Application No. 61/094,816, filed Sep. 5, 2008, entitled “COMPACT HOUSING FOR PORTABLE ELECTRONIC DEVICE WITH INTERNAL SPEAKER”, which is hereby incorporated herein by reference. 
    
    
     BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates to the manufacture of devices which include acoustical speakers. 
     2. Description of the Related Art 
     Piezoelectric speakers, or piezo speakers, are often used in small electronic devices such as portable media players and cellular telephones because of their low profile and relatively small footprint. As will be appreciated by those skilled in the art, piezo speakers create sound by forming vibrations with a diaphragm via a piezoelectric driver. In general, the sound quality associated with piezo speakers is adequate, but is often not to the level that may be desired in particular applications. The sound quality associated with piezo speakers may be worsened by the actual placement of the piezo speakers within electronic devices. That is, the location at which a piezo speaker is placed may not be a location which is not substantially optimal for the performance of the piezo speaker. Piezo speakers are often placed wherever they fit within electronic devices, without regard for whether the placement of the piezo speakers provides substantially the best sound quality that may be achieved by the piezo speakers. 
     Although components within an electronic device, e.g., components mounted on a printed circuit board of the electronic device, may be moved to accommodate the placement of a piezo speaker such that the sound quality associated with the electronic device may be enhanced. However, moving other components is not always possible. For example, moving some components may adversely affect the overall performance of an electronic device. 
     Therefore, what is needed is a method and an apparatus which allows piezo speakers to be located within electronic devices such that the piezo electric speakers provide a relatively high sound quality without compromising the performance of other components within the electronic devices. 
     SUMMARY OF THE INVENTION 
     The present invention pertains to a method and an apparatus which allows a speaker to substantially cooperate with other components of an electronic device to provide improved acoustical output. For example, a speaker, such as a piezoelectric speaker, can utilize an electromagnetic interference (EMI) shield to provide improved audio from the electronic device. 
     The present invention may be implemented in numerous ways, including, but not limited to, as a method, system, device, or apparatus. Example embodiments of the present invention are discussed below. 
     According to one embodiment, an electronic apparatus includes at least: a substrate configured to support one or more electronic components coupled thereto; a can secured to the substrate over and around the one or more electronic components; and a speaker at least partially mounted on the can. 
     According to one embodiment, an electronic device includes at least a printed circuit board (PCB), a component and a speaker. The component can be mounted on the PCB and substantially enclose a volume of air. The speaker can be mounted on a surface of the component so that the volume of air enclosed by the component serves as a back volume for enhancing sound waves produced by the speaker. 
     According to one embodiment, an apparatus includes a substrate, a can mounted on the substrate, and a piezoelectric speaker arrangement. The piezoelectric speaker arrangement is at least partially mounted on the can. In one embodiment, the substrate is a printed circuit board (PCB) and the can is an EMI shielding can. 
     According to another one embodiment, an electronic device includes a PCB, at least one electrical component mounted on the PCB, and an EMI shield mounted on the PCB over and around the electrical component. The electronic device also includes a piezoelectric speaker arrangement. The piezoelectric speaker arrangement includes a diaphragm element that is mounted on a surface of the EMI shield. 
     In accordance with yet another embodiment, a method of assembling an electronic device includes attaching at least a portion of a piezoelectric speaker arrangement to an EMI can, and then attaching the EMI can to a PCB. The PCB has at least one electrical component mounted thereon. The EMI can is attached or mounted to the PCB over and around the electrical component. 
     Other aspects and advantages of the invention will become apparent from the following detailed description taken in conjunction with the accompanying drawings which illustrate, by way of example, the principles of the invention. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The invention will be readily understood by the following detailed description in conjunction with the accompanying drawings, in which: 
         FIG. 1  is a diagrammatic representation of a printed circuit board (PCB) assembly which includes a piezo speaker mounted on an electromagnetic interference (EMI) shielding can in accordance with an embodiment of the present invention. 
         FIG. 2A  is a block diagram side-view representation of a piezo speaker vibrating when mounted on an EMI shielding can in accordance with an embodiment of the present invention. 
         FIG. 2B  is a block diagram side-view representation of an EMI shielding can, e.g., EMI shielding can  212  of  FIG. 2A , vibrating with a piezo speaker mounted thereon in accordance with an embodiment of the present invention. 
         FIG. 3A  is a diagrammatic side-view cross-sectional representation of a PCB assembly which includes a piezo speaker mounted on an EMI shielding can that includes openings in a top surface in accordance with an embodiment of the present invention. 
         FIG. 3B  is a diagrammatic top-view representation of a PCB assembly, e.g., PCB assembly  300  of  FIG. 3A , in accordance with an embodiment of the present invention. 
         FIG. 4  is a process flow diagram which illustrates a method of assembling a PCB assembly that includes a piezo speaker mounted on an EMI shielding can in accordance with an embodiment of the present invention. 
         FIG. 5A  is a diagrammatic side-view cross-sectional representation of a PCB assembly which includes a piezo speaker mounted on an EMI shielding can that does not include openings in a top surface in accordance with an embodiment of the present invention. 
         FIG. 5B  is a diagrammatic top-view representation of a PCB assembly, e.g., PCB assembly  500  of  FIG. 5A , in accordance with an embodiment of the present invention. 
         FIG. 6  is a diagrammatic side-view representation of a portable electronic device in which front and back volumes are created for use with a piezo speaker mounted on an EMI shielding can in accordance with an embodiment of the present invention. 
         FIG. 7  is a diagrammatic representation of a PCB assembly which includes a piezo speaker mounted on an EMI shielding can formed from a fence and a cover in accordance with an embodiment of the present invention. 
         FIG. 8  is a block diagram representation of an overall speaker arrangement which includes a piezo speaker and an EMI shielding can in accordance with an embodiment of the present invention. 
         FIG. 9  illustrates a cross-sectional view of a portion of a portable electronic device according to one embodiment of the invention. 
         FIG. 10A  illustrates a cross-sectional view of a PCB and speaker assembly according to one embodiment of the invention. 
         FIG. 10B  illustrates a cross-sectional view of a PCB and speaker assembly according to another embodiment of the invention. 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     Example embodiments of the present invention are discussed below with reference to the various figures. However, those skilled in the art will readily appreciate that the detailed description given herein with respect to these figures is for explanatory purposes, as the invention extends beyond these embodiments. 
     The present invention pertains to a method and an apparatus which allows a speaker to substantially cooperate with other components of an electronic device to provide improved acoustical output. For example, a speaker, such as a piezoelectric speaker, can utilize an electromagnetic interference (EMI) shield to provide improved audio from the electronic device. 
     Electronic devices, e.g., portable media players, mobile phones, personal digital assistants, generate electromagnetic interference (EMI). EMI is a disturbance which can have an adverse effect on other nearby electrical circuits. To reduce the effects of EMI, EMI shields or EMI shielding cans are often used to mitigate electromagnetic disturbances. 
     In one embodiment, a piezoelectric speaker, or a piezo speaker, may be attached to or otherwise mounted on an EMI shielding can such that the resultant arrangement is effectively a combination speaker and EMI shield. By attaching a piezo speaker, or some feature of the piezo speaker, on an EMI shielding can of an electronic device, the performance of the piezo speaker may be enhanced. When at least a part of the piezo speaker is attached to a surface of the EMI shielding can, overall acoustical performance associated with the electronic device can be improved. When the piezo speaker vibrates, the EMI shielding can amplifies the sound generated by the piezo speaker. 
     Mounting a piezo speaker arrangement, or some portion thereof, on an EMI shielding generally does not affect the shielding capabilities provided by the EMI shielding can. Further, the placement of the piezo speaker typically does not impinge on the placement of the EMI shielding can or other components of an electronic device. Hence, the placement of a piezo speaker on the EMI shielding can of the electronic device enhances the sound quality provided by the piezo speaker without adversely impacting the performance of other components within the electronic device. 
     To further improve the sound quality associated with an electrical device which includes a piezo speaker, the piezo speaker may effectively be attached to an EMI shielding can and sealed thereto such that a back volume for the piezo speaker includes the volume (or air) within the EMI shield can. The existence of the enlarged back volume further enhance the sound quality provided by an overall speaker arrangement that includes the piezo speaker and the EMI shielding can. 
     As will be appreciated by those skilled in the art, an EMI shielding can may be attached to a printed circuit board (PCB) or, more generally, a substrate of an electronic device. Such a PCB may be supported within a housing of the electronic device. A PCB assembly which includes a PCB that supports an EMI shielding can on which a piezo speaker is mounted will be described in accordance with an embodiment of the present invention. As illustrated in  FIG. 1 , a PCB assembly  100  includes a PCB  104  on which electrical traces are typically formed and electrical components (not shown) are mounted. An EMI shield or EMI shielding can  112  is positioned over and around the electrical components (not shown), and substantially attached to PCB  104 . 
     EMI shielding can  112  may be formed from substantially any material which is suitable for providing EMI shielding. By way of example, EMI shielding can  112  may be formed from a metal. Other materials form which EMI shielding can  112  may be formed include, but are not limited to including, non-metal materials which include a metallic layer. Such non-metal materials may include composite materials, laminated materials, paper, rubber, plastic, ceramics, fiberglass, and glass. A metallic layer may be formed, as for example coated or painted, onto the non-metal materials. In one embodiment, EMI shielding can  112  may be formed from a rubber material that is coated with metal. 
     A piezo speaker  118  is mounted on or attached to EMI shielding can  112 . Piezo speaker  118  may include components including, but not limited to including, a piezo element, e.g., a diaphragm or thin membrane, and a piezo driver element. It should be appreciated that although piezo speaker  118  is shown as being mounted to a top surface or wall of EMI shielding can  112 , piezo speaker  118  may generally be mounted on substantially any surface of EMI shielding can  112 . As the top surface of EMI shielding can  112  often extends over a relatively large area of PCB  104 , piezo speaker  118  is typically mounted on the top surface of EMI shielding can  112  rather than a side surface of EMI shielding can  112  due to the better acoustical performance that may be achieved. Piezo speaker  118  may be mounted on EMI shielding can  112  using any suitable method. By way of example, piezo speaker  118  may be attached to EMI shielding can  112  using an adhesive material (e.g., epoxy, glue, etc). 
     When piezo speaker  118  vibrates, EMI shielding can  112  vibrates and, thus, causes sound generated by piezo speaker  118  to be substantially amplified.  FIG. 2A  is a block diagram side-view representation of a piezo speaker vibrating when mounted on an EMI shielding can in accordance with an embodiment of the present invention. A piezo speaker  218  is mounted on an EMI shielding can  212  which, in turn, is attached to a substrate such as a PCB  204 . Piezo speaker  218  may vibrate, as shown. In general, piezo speaker  218  includes a relatively thin membrane or diaphragm which vibrates to create sound when driven by a piezo driver. 
     The vibrations associated with piezo speaker  218  effectively cause EMI shielding can  212  to vibrate.  FIG. 2B  is a block diagram side-view representation of EMI shielding can  212  vibrating along with piezo speaker  218  in accordance with an embodiment of the present invention. When piezo speaker  218  vibrates, the vibrations are transmitted to EMI shielding can  212  which, in turn, also vibrates. When EMI shielding can  212  vibrates, the lower end frequency response associated with the sounds generated by the vibration of piezo speaker  218  is typically increased, i.e., the sound pressure level or loudness is increased. That is, EMI shielding can  212  amplifies the sound generated by piezo speaker  218  by vibrating along with piezo speaker  218 . 
     In one embodiment, an EMI shielding can may include openings in a top surface. The openings allow the sound waves generated by the piezo speaker  218  into the EMI shielding can, provided that the EMI shield can is otherwise substantially sealed (e.g., to the PCB). This allows the volume of air within EMI shield to be used as at least part of the back volume for the piezo speaker.  FIG. 3A  is a diagrammatic side-view cross-sectional representation of a PCB assembly which includes a piezo speaker mounted on an EMI shielding can that includes openings in a top surface, and  FIG. 3B  is a diagrammatic top-view representation of the PCB assembly in accordance with an embodiment of the present invention. As shown in  FIG. 3 , PCB assembly  300  includes a PCB  304  or, more generally, a substrate. Various components  308 , e.g., electrical components, are mounted on PCB  304 . 
     PCB assembly  300  also includes an EMI shielding can  312  in which openings  322  are defined. The number of openings  322 , as well as the size and shape of openings  322 , may vary widely. In this embodiment, openings  322  are provided on a top surface of EMI shielding can  312 . A piezo speaker arrangement  318  can be mounted on the top surface of EMI shielding can  312  such that openings  322  are substantially covered or overlaid by piezo speaker arrangement  318 . The opening  322  allowing the internal volume of EMI shielding can  312  to serve as a substantially portion of a back volume for piezo speaker arrangement  318 . 
     Piezo speaker arrangement  318  includes, in one embodiment, a support member  318   a  that holds or otherwise supports a diaphragm  318   b . Support member  318  may generally support any number of sides of diaphragm  318   b . By way of example, support member  318  may support all sides of diaphragm  318   b  along its periphery. A piezo driver (not shown) may be used to cause diaphragm  318   b  to vibrate. In one embodiment, diaphragm  318   b  is a relatively thin rubber membrane or any other thin structure that vibrates when driven by a piezo driver (not shown). Support member  318   a  may be directly attached to a top surface of EMI shielding can  312  or indirectly attached to the top surface of EMI shielding can  312  via a gasket  316 . As shown, gasket  316  can serve as an interface through which piezo speaker arrangement  318  is mounted on EMI shielding can  312  substantially over openings  322 . As an example, an adhesive material, such as epoxy or glue, can be used to attach support member  318   a  directly or indirectly to the top surface of EMI shield can  312 . 
     With reference to  FIG. 4 , one method of assembling a PCB assembly that includes a piezo speaker mounted on an EMI shielding can will be described in accordance with an embodiment of the present invention. A process  401  of assembling a PCB assembly begins at step  405  in which a PCB, an EMI shielding can, a piezo speaker arrangement, and other components, e.g., electrical components, are obtained. That is, the parts which are to form an overall PCB assembly are obtained. 
     The electrical components are attached to the PCB in step  409 . Attaching electrical components to the PCB generally includes soldering electrical components to the PCB, as will be appreciated by those skilled in the art. After electrical components are attached to the PCB, at least a part of a piezo speaker arrangement is mounted to the EMI shielding can in step  413 . In one embodiment, substantially all of a piezo speaker arrangement may be mounted to the EMI shielding can. It should be appreciated, however, that part of the piezo speaker arrangement, e.g., a piezo diaphragm and a support structure, may essentially be mounted on the EMI shielding can while other parts of the piezo speaker arrangement, e.g., a piezo speaker driver, may be mounted off of the EMI shielding can. 
     Once at least a part of the piezo speaker arrangement is mounted on the EMI shielding can in step  413 , the EMI shielding can is attached to the PCB in step  417 . Attaching the EMI shielding can to the PCB may include, but is not limited to including, soldering, adhering or otherwise securing the EMI shielding can to the PCB. 
     Some EMI shielding cans include gaps (or openings) formed around the edges. In one embodiment, such gaps are substantially closed in order to improve the acoustical qualities associated with the speaker assembly formed from the piezo speaker and the EMI shielding can. As such, a determination is made in step  421  as to whether the EMI shielding can has gaps that are to effectively be closed. If the determination is that the EMI shielding can does not have gaps that are to effectively be closed, the process of assembling a PCB assembly is completed. Alternatively, if it is determined that the EMI shielding can has gaps that are effectively to be closed, then the gaps are effectively closed in step  425 . The gaps can be effectively closed by being covered or filled. For example, closing the gaps may include, but is not limited to including, taping over the gaps, filling the gaps with a material such as foam, or applying solder in the gaps. After the gaps in the EMI shielding can are effectively closed, the process of assembling a PCB assembly is completed. 
     As described above with respect to  FIGS. 3A and 3B , a top surface of an EMI shielding can may include openings. Such openings effectively enable the internal volume of the EMI shielding can to form a back volume of an overall speaker arrangement formed from the EMI shielding can and a piezo speaker. It should be appreciated, however, that the top surface of an EMI shielding can may include no openings. When the top surface of an EMI shielding can does not include openings, a back volume may be formed between a piezo speaker and the top surface of the EMI shielding can. Referring next to  FIGS. 5A and 5B , a PCB assembly which includes a piezo speaker mounted on an EMI shielding can that does not include openings in a top surface will be described in accordance with an embodiment of the present invention.  FIG. 5A  is a diagrammatic side-view cross-sectional representation of a PCB assembly, and  FIG. 5B  is a diagrammatic top-view representation of the PCB assembly. A PCB assembly  500  includes a PCB or a substrate  504  into which various components  508 , e.g., electrical components, are mounted. An EMI shielding can  512 , which includes substantially no holes in a top surface, is mounted to PCB  504  such that EMI shielding can  512  is essentially positioned around and over components  508 . That is, EMI shielding can  512  is arranged to shield components  508 . 
     A piezo speaker arrangement  518  is mounted on a top surface of EMI shielding can  512 . Piezo speaker arrangement  518  includes a support member  518   a  that holds a diaphragm  518   b . Support member  518   a  is effectively attached to a top surface of EMI shielding can  512  through a gasket  516 . That is, gasket  516  is the interface through which piezo speaker arrangement  518  is mounted on EMI shielding can  512 . It should be appreciated, however, that in lieu of gasket  516 , support member  518   a  may be substantially directly mounted to EMI shielding can  512 , e.g., using an adhesive material such as epoxy. 
     A space  520  formed between diaphragm  518   b , or a flexible membrane, and a top surface of EMI shielding can  512  may be a back volume of an overall speaker that includes EMI shielding can  512  and piezo speaker arrangement  518 . In one embodiment, the distance between the top surface of EMI shielding can  512  and diaphragm  518   b  is in the range of approximately 0.05 millimeters to 2.0 millimeters. The distance and, hence, the size of the back volume, may generally be adjusted by varying the thickness of gasket  516  and/or support member  518   a.    
     In one embodiment, a piezo speaker mounted on an EMI shielding can may be incorporated into an overall system such that front and back volumes are defined.  FIG. 6  is a diagrammatic side-view representation of a portable electronic device in which front and back volumes are created for use with a piezo speaker mounted on an EMI shielding can in accordance with an embodiment of the present invention. A portable electronic device  602  includes a PCB  604  on which an EMI shielding can  612  is mounted. A piezo speaker  618  is mounted on EMI shielding can  612 . The portion of the EMI shielding can  612  adjacent piezo speaker  618  may include one or more openings  619  over which piezo speaker  618  is mounted. 
     A connector  630 , e.g., a 30-pin connector, is mounted on PCB  604  such that connector  630  is able to be associated with a front volume  638  within a housing  626 . The connector  630  also services as an audio exit opening through which audio sounds can be emitted. A back volume  642  can be defined by an internal volume of EMI shielding can  612 . Here, EMI shielding can  612  is sealed to PCB  604  so that the internal volume is an enclosed volume. Additionally, one or more seals  634  can be provided within portable electronic device  602  to create a front volume  638  for piezo speaker  618 . 
     An EMI shielding can has generally been described as being formed from a single piece, as for example a single piece of stamped sheet metal. In lieu of being formed from a single piece, an EMI shielding can may be formed from multiple separate pieces.  FIG. 7  is a diagrammatic representation of a PCB assembly which includes a piezo speaker mounted on an EMI shielding can formed from two substantially separate pieces in accordance with an embodiment of the present invention. A PCB assembly  700  includes a PCB  704  on which electrical traces are typically formed and electrical components (not shown) are mounted. An EMI shielding can assembly  712  is positioned over and around the electrical components (not shown), and substantially attached to PCB  704 . 
     EMI shielding can assembly  712  includes a cover  712   a  and a fence  712   b . Fence  712   b  is generally configured to be attached to PCB  704 , and cover  712   a  is configured to substantially engage with fence  712   b  to form EMI shielding can assembly  712 . Cover  712   a  may, in one embodiment, be sealed against fence  712   b . A piezo speaker  718  is generally mounted on a top surface of cover  712   a.    
     With reference to  FIG. 8 , one embodiment of a speaker arrangement which includes a piezo speaker and an EMI shielding can will be described in accordance with the present invention. An overall speaker arrangement  850  includes a piezo speaker arrangement  818  that is mounted on an EMI shielding can  812 . EMI shielding can  812  is typically mounted on a PCB or, more generally, a substrate  804 . Piezo speaker arrangement  818  includes a support structure  818   a  which supports a vibrating element  818   b , e.g., a diaphragm or a thin membrane, over a surface of EMI shielding can  812 . Support structure  818   a  may generally be a structure (e.g., metal structure), and is coupled to EMI shielding can  812 . Support structure  818   a  may, in one embodiment, be arranged about the periphery of vibrating element  818   b . As shown, support structure  818   a  may be coupled to EMI shielding can  812  using a gasket  816 . Alternatively, it should be appreciated that support structure  818   a  may instead be substantially directly coupled to EMI shielding can  812 . 
       FIG. 9  illustrates a cross-sectional view of a portion of a portable electronic device  900  according to one embodiment of the invention. The portable electronic device  900  includes a PCB assembly having a PCB (or substrate)  902  having various components  904 , e.g., electrical components, mounted thereon. An EMI shielding can  906  can be mounted to PCB  902  such that EMI shielding can  906  is essentially positioned around and over components  904 . That is, EMI shielding can  906  is arranged to shield components  904 . 
     A piezo speaker arrangement  908  is mounted on a top surface of EMI shielding can  906 . Piezo speaker arrangement  908  includes a support member that holds a diaphragm  908   c . More particularly, the support member can have a top portion  908   a  and a bottom portion  908   b . In one implementation, the support member is a metal frame that is attached to the ends of diaphragm  908   c . The diaphragm  908   c  can, for example, be disc-shaped piezo electric element, and the support member can have a ring shape. Support member  908   b  can be effectively attached to a top surface of EMI shielding can  906  through a gasket  910 . That is, gasket  910  is the interface through which piezo speaker arrangement  908  is mounted on EMI shielding can  906 . In one implementation, gasket  910  can pertain to double-sided adhesive tape (e.g., VHB). It should be appreciated, however, that in lieu of gasket  910 , support member  908   b  may be substantially directly mounted to EMI shielding can  512 , e.g., using an adhesive material such as epoxy. Regardless, piezo speaker arrangement  908  is sealed to the top surface of EMI shielding can  906 . Between diaphragm  908   c  and the top surface of EMI shielding can  906  is an open region  912 . Also, adjacent the open region  912  (or space), the top surface of EMI shielding can  906  includes one or more openings  914 . 
     The portable electronic device  900  can also include a housing  916 . The housing  916  can serve as an outer housing for portable electronic device  900 . The PCB assembly with piezo speaker arrangement  908  are arranged within housing  916 . Additionally, piezo speaker arrangement  908  can be sealed with respect to an inner surface of housing  916 . In this regard, one or more seals  918  can seal an upper surface of piezo speaker arrangement  908  to the inner surface of housing  916 . As examples, the seals  918  can be formed of silicone, rubber or other compliant material suitable for creating a seal. The sealing of piezo speaker arrangement  908  to the inner surface of housing  916  forms a sealed volume  920  that can serve as a back volume for piezo speaker arrangement  908 . Additionally, the sealed volume  920  can be enlarged by a recessed area  922  in the inner surface of housing  916 . The recessed area  922  can, for example, be formed through molding, machining or chemical etching. The presence of the recessed area  922  serves to enlarge the sealed volume  920  which increases the back volume for piezo speaker arrangement  908 . The larger back volume can yield better audio quality and/or performance for piezo speaker arrangement  908 . The resulting thinned portion of housing  916  at recessed area  922  may also provide improved acoustic performance by facilitating internally generally sound from propagating out of housing  916 . 
       FIG. 10A  illustrates a cross-sectional view of a PCB and speaker assembly  1000  according to one embodiment of the invention. The PCB and speaker assembly  1000  includes a PCB assembly having a PCB (or substrate)  1002  having various components  1004 , e.g., electrical components, mounted thereon. An EMI shielding can  1006  can be mounted to PCB  1002  such that EMI shielding can  1006  is essentially positioned around and over components  1004 . That is, EMI shielding can  1006  is arranged to shield components  1004 . 
     The PCB and speaker assembly  1000  also includes a piezo speaker arrangement  1008  mounted on a top surface of EMI shielding can  1006 . As illustrated in  FIG. 10A , the top surface of EMI shielding can  1006  can include a recess area  1009 . Piezo speaker arrangement  1008  can be mounted on the top surface of EMI shielding can  1006  at recess area  1009 . Piezo speaker arrangement  1008  includes a support member that holds a diaphragm  1008   c . More particularly, the support member can have a top portion  1008   a  and a bottom portion  1008   b . In one implementation, the support member is a metal frame that is attached to the ends of diaphragm  1008   c . The diaphragm  1008   c  can, for example, be a disc-shaped piezo electric element, and the support member can have a ring shape. Support member  1008   b  can be effectively attached to a top surface of EMI shielding can  1006  through a gasket  1010 . That is, gasket  1010  is the interface through which piezo speaker arrangement  1008  is mounted on EMI shielding can  1006 . In one implementation, gasket  1010  can pertain to double-sided adhesive tape (e.g., VHB). It should be appreciated, however, that in lieu of gasket  1010 , support member  1008   b  may be substantially directly mounted to EMI shielding can  1006 , e.g., using an adhesive material such as epoxy. Regardless, piezo speaker arrangement  1008  is sealed to the top surface of EMI shielding can  1006 . Between diaphragm  1008   c  and the top surface of EMI shielding can  1006  is an open region  1012 . Also, adjacent the open region  1012  (or space), the top surface of EMI shielding can  1006  includes one or more openings  1014 . 
     In one embodiment, the open region  1012  together with an internal volume  1016  within EMI shielding can  1006  provide a sealed volume, which can be used as a back volume for piezo speaker arrangement  1008 . In an alternative embodiment, although not shown in  FIG. 10A , piezo speaker arrangement  1008  can alternatively or additionally be sealed to an inner surface of a housing such as illustrated in  FIG. 9 , thereby forming a sealed volume that can serve as a back volume for piezo speaker arrangement  1008 . 
       FIG. 10B  illustrates a cross-sectional view of a PCB and speaker assembly  1050  according to another embodiment of the invention. The PCB and speaker assembly  1050  includes a PCB assembly having a PCB (or substrate)  1002  having various components  1004 , e.g., electrical components, mounted thereon. An EMI shielding can  1006  can be mounted to PCB  1002  such that EMI shielding can  1006  is essentially positioned around and over components  1004 . That is, EMI shielding can  1006  is arranged to shield components  1004 . 
     The PCB and speaker assembly  1000  also includes a piezo speaker arrangement  1052  mounted on a top surface of EMI shielding can  1006 . As illustrated in  FIG. 10A , the top surface of EMI shielding can  1006  can include a recess area  1009 . Piezo speaker arrangement  1052  can be mounted on the top surface of EMI shielding can  1006 . Optionally, piezo speaker arrangement  1052  can mounted on the top surface of EMI shielding can  2006  at recess area  1009 . Piezo speaker arrangement  1052  includes a support member  1052   a  that holds a diaphragm  1052   b . In this embodiment, the support member  1052   a  is provided only on one side of diaphragm  1052   b . In one implementation, the support member  1052   a  is a metal frame that is attached to the ends of diaphragm  1052   b . The diaphragm  1052   b  can, for example, be a disc-shaped piezo electric element, and the support member can have a ring shape. Diaphragm  1052   b  can be effectively attached to a top surface of EMI shielding can  1006 . The attachment can, for example, be performed using a thin layer of adhesive. Piezo speaker arrangement  1052   b  is thus sealed to the top surface of EMI shielding can  1006 . Between diaphragm  1052   b  and the top surface of EMI shielding can  1006  is an open region  1012 . Also, adjacent the open region  1012  (or space), the top surface of EMI shielding can  1006  includes one or more openings  1014 . 
     In one embodiment, the open region  1012  together with an internal volume  1016  within EMI shielding can  1006  provide a sealed volume, which can be used as a back volume for piezo speaker arrangement  1052 . In an alternative embodiment, although not shown in  FIG. 10B , piezo speaker arrangement  1052  can alternatively or additionally be sealed to an inner surface of a housing such as illustrated in  FIG. 9 , thereby forming a sealed volume that can serve as a back volume for piezo speaker arrangement  1052 . 
     Advantageously, piezo speaker arrangement  1052  has a reduced height (i.e., z-axis) as compared to piezo speaker arrangement  1008  illustrated in  FIG. 10A . Namely, a bottom portion of a support member for diaphragm  1008   b  is eliminated. Instead, any additional structural support can be provided by EMI shielding can  1006  to which piezo speaker arrangement  1008  is attached. Also, gasket  1010  can be eliminated and, as noted above, a thin layer of adhesive can be used to secure piezo speaker arrangement  1008  to EMI shielding can  1006 . 
     In still another embodiment, a piezo speaker arrangement could be mounted internal to an EMI shielding can. In such case, the EMI shielding can may operate as a sealed volume as all or part of a front volume or a back volume. The EMI shielding can may also serves to provide a protective housing for a piezo element of the piezo speaker arrangement. 
     Although only a few embodiments of the present invention have been described, it should be understood that the present invention may be embodied in many other specific forms without departing from the spirit or the scope of the present invention. By way of example, a piezo speaker has generally been described as including a vibrating element such as a diaphragm and a support member which supports the diaphragm. Such a vibrating element and support member are generally unprotected, as they are not encased in a protective case. However, in one embodiment, such a vibrating element and support member may at least be partially encased in a protective case. 
     While a piezo speaker has been described as being attached to or otherwise mounted on an EMI shielding can, it should be appreciated that a portion of the piezo speaker may be attached to the EMI shielding can while other portions of the piezo speaker may be mounted off of the EMI shielding can. For example, a piezo element that vibrates may be mounted on an EMI shielding can while other elements of the piezo speaker, such as a piezo driver, may be mounted off of the EMI shielding can. Typically, the piezo element that vibrates is a diaphragm or a membrane. 
     In general, a piezo speaker may be mounted on a top surface of an EMI shielding can. However, a piezo speaker is not limited to being mounted on a top surface of an EMI shielding can. For instance, a piezo speaker may be mounted on a side wall or a fence of an EMI shielding can. 
     An EMI shielding can may be configured to meet acoustical performance specifications as needed. That is, the material from which an EMI shielding can is formed, as well as the geometry of the EMI shielding can, may be altered to meet the acoustical requirements of particular systems in which the EMI shielding can is included. By way of example, the geometry of an EMI shielding can may be tuned to provide a desired range of frequencies. Tuning the geometry may include, but is not limited to including, varying the internal volume of the EMI shielding can, varying the flexibility of the various walls of the EMI shielding can, varying the material from which the various walls are formed, and/or varying the thickness of the various walls. Further, varying the rigidity and/or the stiffness of the EMI shielding can may allow the acoustical performance to be adjusted. In one embodiment, EMI shielding can may serve as a diaphragm of an overall speaker arrangement. 
     An EMI shielding can may be mounted to a PCB in a substantially fixed manner. That is, an EMI shielding can may be soldered to a PCB, as previously mentioned. Alternatively, however, an EMI shielding can may be attached to a PCB through a dampening or elastic material if, for example, acoustical qualities are such that attaching the EMI shielding can to a PCB through a dampening material is preferable. 
     In one embodiment, the electronic device as described herein is mobile electronic device that provides an audio output. In one implementation, the mobile device can be a handheld electronic device. The term hand-held generally means that the electronic device has a form factor that is small enough to be comfortably held in one hand of a user (person). A hand-held electronic device may be directed at one-handed operation or two-handed operation. In one-handed operation, a single hand is used to both support the device as well as to perform operations with the user interface during use. In two-handed operation, one hand is used to support the device while the other hand performs operations with a user interface during use or alternatively both hands support the device as well as perform operations during use. In some cases, the hand-held electronic device is sized for placement into a pocket of the user. By being pocket-sized, the user does not have to directly carry the device and therefore the device can be taken almost anywhere the user travels (e.g., the user is not limited by carrying a large, bulky and often heavy device). 
     The operations associated with the various methods of the present invention may vary widely. By way of example, steps may be added, removed, altered, combined, and reordered without departing from the spirit or the scope of the present invention. 
     The many features and advantages of the present invention are apparent from the written description. Further, since numerous modifications and changes will readily occur to those skilled in the art, the invention should not be limited to the exact construction and operation as illustrated and described. Hence, all suitable modifications and equivalents may be resorted to as falling within the scope of the invention.

Metadata:
Filing Date: 20120221
Publication Date: 20130604
Grant Date: 20130604
Priority Date: 20080905
Inventors: YEATES KYLE
LYNCH STEPHEN BRIAN
DABOV TEODOR
Assignee: APPLE INC
CPC Classifications: [{"code": "H04R2499/11", "inventive": false, "first": false, "tree": "[]"}, {"code": "H04R17/00", "inventive": true, "first": true, "tree": "[]"}, {"code": "Y10T29/53174", "inventive": false, "first": false, "tree": "[]"}, {"code": "Y10T29/53174", "inventive": false, "first": false, "tree": "[]"}, {"code": "H04R2499/11", "inventive": false, "first": false, "tree": "[]"}, {"code": "H04R17/00", "inventive": true, "first": true, "tree": "[]"}, {"code": "H04R17/10", "inventive": false, "first": false, "tree": "[]"}, {"code": "H04R17/10", "inventive": false, "first": false, "tree": "[]"}]
Family ID: 41334369