Abstract:
An electronic device includes: a component accommodated within a housing; a first fitting portion protruding from an inner surface of the housing toward the component; and a second fitting portion fitted to the first fitting portion, the second fitting portion including a second abutting surface abutted on a first abutting surface of the first fitting portion, wherein the component is sealed in a component chamber by a sealing member constituted by the first fitting portion and the second fitting portion, and a groove or a lateral hole is formed in the first abutting surface or the second abutting surface.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
       [0001]    This application is based upon and claims the benefit of priority of the prior Japanese Patent Application No. 2014-077993 filed on Apr. 4, 2014, the entire contents of which are incorporated herein by reference. 
       FIELD 
       [0002]    The embodiments discussed herein are related to an electronic device and an assembly method of the electronic device. 
       BACKGROUND 
       [0003]    An acoustic component such as a microphone or a speaker, which is a non-water resistant electronic component, may be mounted on an electronic device such as a mobile phone or a tablet computer. When an acoustic component is assembled with a housing, a compressible member such as rubber or foamed urethane may be interposed between the acoustic component or a substrate mounted with the acoustic component and the housing so that the electronic device is assembled by pressurizing the compressible member. 
         [0004]    When an electronic device is assembled as described above, an acoustic component chamber including the acoustic component may be isolated from another space within the housing, and its airtightness may be improved. As a result, sound is suppressed from leaking from the acoustic component chamber, or noise is suppressed from intruding from another space within the housing into the space of the acoustic component chamber, thereby improving the sensitivity of the acoustic component. 
         [0005]    A waterproof cover may cover a sound hole formed in the housing so as to suppress the acoustic component within the housing from being broken through repetitive submergences of the electronic device. However, the waterproof cover has been made of a material whose waterproof ability is reduced when the cover is in contact with sea water or soapy water. 
         [0006]    However, a waterproof cover made of a material whose waterproof ability is not reduced even when the cover is in contact with sea water or soapy water does not have an air-permeability (permeability). When the non-air permeable waterproof cover is employed, there is no escape space of air in the acoustic component chamber while the acoustic component is assembled with the housing. Accordingly, the internal pressure of the acoustic component chamber may be largely increased so that, for example, a diaphragm (a vibration plate) of the acoustic component may be damaged. 
         [0007]    The following are reference documents. 
         [0008]    [Document 1] Japanese Laid-Open Patent Publication No. 2013-5349, and 
         [0009]    [Document 2] Japanese Laid-Open Patent Publication No. 2013-121059. 
       SUMMARY 
       [0010]    According to an aspect of the invention, An electronic device includes: a component accommodated within a housing; a first fitting portion protruding from an inner surface of the housing toward the component; and a second fitting portion fitted to the first fitting portion, the second fitting portion including a second abutting surface abutted on a first abutting surface of the first fitting portion, wherein the component is sealed in a component chamber by a sealing member constituted by the first fitting portion and the second fitting portion, and a groove or a lateral hole is formed in the first abutting surface or the second abutting surface. 
         [0011]    The object and advantages of the invention will be realized and attained by means of the elements and combinations particularly pointed out in the claims. 
         [0012]    It is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory and are not restrictive of the invention, as claimed. 
     
    
     
       BRIEF DESCRIPTION OF DRAWINGS 
         [0013]      FIG. 1  is an external view of a mobile phone according to an exemplary embodiment 1; 
           [0014]      FIG. 2  is a first exploded view illustrating a part of the mobile phone according to the exemplary embodiment 1; 
           [0015]      FIG. 3  is a second exploded view illustrating a part of the mobile phone according to the exemplary embodiment 1; 
           [0016]      FIG. 4  is a cross-sectional view illustrating a waterproof structure of the mobile phone according to the exemplary embodiment 1; 
           [0017]      FIG. 5  is a first perspective view illustrating a sealing pedestal according to the exemplary embodiment 1; 
           [0018]      FIG. 6  is a second perspective view illustrating the sealing pedestal according to the exemplary embodiment 1; 
           [0019]      FIG. 7  is a view illustrating the mobile phone according to the exemplary embodiment 1 which is being assembled; 
           [0020]      FIG. 8  is a view explaining a mobile phone according to a modified example 1; 
           [0021]      FIG. 9  is a view explaining a mobile phone according to a modified example 2; 
           [0022]      FIG. 10  is a view explaining a mobile phone according to a modified example 3; 
           [0023]      FIG. 11  is a view explaining a mobile phone according to a modified example 4; 
           [0024]      FIG. 12  is a view explaining a mobile phone according to a modified example 5; 
           [0025]      FIG. 13  is a view explaining a mobile phone according to a modified example 6; and 
           [0026]      FIG. 14  is a view explaining a mobile phone according to a modified example 7. 
       
    
    
     DESCRIPTION OF EMBODIMENTS 
       [0027]    Hereinafter, descriptions will be made on an electronic device and an assembly method thereof according to an exemplary embodiment of the present disclosure with reference to drawings. 
       Exemplary Embodiment 1 
       [0000]    
       
         
           
               FIG. 1  is an external view of a mobile phone  1  as an electronic device according to an exemplary embodiment 1. The mobile phone  1  includes a housing  10 , and various components are embedded within the housing  10 . 
           
         
       
     
         [0029]      FIGS. 2 and 3  illustrate a front housing  11  and a rear housing  12  which are parts of the housing  10 . The front housing  11  and the rear housing  12  may be manufactured by molding, for example, a synthetic resin such as polycarbonate or ABS resin. The front housing  11  and the rear housing  12  are connected to each other through a water stop packing (not illustrated) sandwiched between the front housing  11  and the rear housing  12 . 
         [0030]      FIG. 4  is a cross-sectional view explaining a waterproof structure of the mobile phone  1  according to the exemplary embodiment, which illustrates a part of a cross-sectional view passing through an air vent groove  54  of a sealing pedestal  5  to be described later. A microphone sound hole  11   a  is provided in the longitudinal direction of the front housing  11  to be used for a call function. The microphone sound hole  11   a  is formed through the front housing  11 , and communicates with the inner space of the housing  10 , that is, a space for accommodating various components, and the outside of the housing  10 . 
         [0031]    For example, a protective cover member  2 , a control board  3 , a microphone  4 , and the sealing pedestal  5  are accommodated within the housing  10 . The microphone  4  is an acoustic component configured to convert sound into an electrical signal, and converts the sound obtained through the microphone sound hole  11   a  into the electrical signal. The microphone  4  is mounted on the control board  3 , and is electrically connected to the control board  3 . The microphone  4  is an example of a non-water resistant component.  FIGS. 2 and 3  illustrate a part of the front housing  11 , the rear housing  12  and the control board  3 . The various components may be acoustic components having a diaphragm (a vibration plate) which may be damaged during assembly, and may include, for example, a speaker besides the microphone. 
         [0032]    The control board  3  is disposed along a planar direction of the front housing  11  and the rear housing  12 , and the microphone  4  is mounted on the control board  3  to face the microphone sound hole  11   a  formed in the front housing  11 . Hereinafter, a surface of the control board  3  mounted with the microphone  4  is called “a mounting surface  3   a .” The microphone  4  includes a vibration plate (not illustrated) for receiving sound, and the vibration plate is disposed to face the microphone sound hole  11   a  formed in the front housing  11 . The microphone  4  is configured to detect a displacement of the vibration plate which vibrates by a sound pressure of the sound entering the inside of the housing from the microphone sound hole  11   a . Then, the microphone  4  converts the received sound into an electrical signal. 
         [0033]    In the mobile phone  1 , the protective cover member  2  is arranged within the housing  10  to suppress water and dust from intruding into the housing  10  from the microphone sound hole  11   a . The protective cover member  2  includes a waterproof film  21  and a holding portion  22  configured to hold the waterproof film  21 . The holding portion  22  has a substantially rectangular parallelepiped shape, and is made of, for example, a compressible material such as polyurethane foam. 
         [0034]    A through hole is formed through the holding portion  22  in the thickness direction, and the waterproof film  21  is provided to close the through hole. The waterproof film  21  is a waterproof sheet having a non-air permeability and a sound transmittance. That is, the waterproof film  21  has a sound permeability, but does not have an air-permeability (permeability). The waterproof film  21  may be made of, for example, polyethylene terephthalate (PET), Polyethylene (PE), or polypropylene (PP). The protective cover member  2  is provided to a location corresponding to the microphone sound hole  11   a  so that the waterproof film  21  covers the microphone sound hole  11   a . In this manner, when the waterproof film  21  is disposed to overlap the microphone sound hole  11   a  of the front housing  11 , water or dust may be suppressed from intruding into the housing  10  from the microphone sound hole  11   a.    
         [0035]    In the present exemplary embodiment, the waterproof film  21  of the protective cover member  2  does not have an air-permeability, and thus its weight may be greater than that of a waterproof film having an air-permeability. The large weight of the waterproof film  21  may reduce the sensitivity of the microphone  4 . Thus, it is desirable to increase the sound insulation of the microphone chamber  6  which faces at least a part of the microphone  4  within the housing  10 . Therefore, in the present exemplary embodiment, the sealing pedestal  5  is interposed between the control board  3  and an inner surface  11   b  of the front housing  11 .  FIGS. 5 and 6  are perspective views illustrating the sealing pedestal  5  according to the exemplary embodiment 1. The microphone chamber  6  is an example of a component chamber. In the present exemplary embodiment, the microphone  4  is accommodated in the microphone chamber  6 . 
         [0036]    The sealing pedestal  5  is an example of a sealing member configured to isolate (shield) the microphone chamber  6  from another space within the housing  10  and seal the microphone chamber  6 . The sealing pedestal  5  is made of a compressible material such as rubber or polyurethane foam, and includes a base  51  and a fitting portion  52 . In the sealing pedestal  5 , the base  51  and the fitting portion  52  are integrally molded. 
         [0037]    The base  51  of the sealing pedestal  5  is fixed to the mounting surface  3   a  of the control board  3  through, for example, an adhesive tape, and has a substantially square planar shape. Reference numeral  51   a  indicates a top surface of the base  51 , and reference numeral  51   b  indicates a bottom surface of the base  51 . A through hole is formed through the base  51  in the thickness direction. Further, the inner portion of the bottom surface  51   b  of the base  51 , except the outer periphery of the bottom surface  51   b , is recessed by one step so that a recess  51   c  is formed in the bottom surface  51   b . When the base  51  of the sealing pedestal  5  is fixed to the mounting surface  3   a  of the control board  3 , a two-sided tape  53  may be disposed in the recess  51   c  of the bottom surface  51   b  to suppress a step from occurring between the two-sided tape  53  and the outer periphery of the bottom surface  51   b . Accordingly, the sealing pedestal  5  may be fixed to the control board  3  in a state where the bottom surface  51   b  of the base  51  is in close contact with the mounting surface  3   a  of the control board  3 . The two-sided tape  53  is formed into an annular shape in plan view so as not to block the through hole of the base  51 . 
         [0038]    The fitting portion  52  of the sealing pedestal  5  is an annular peripheral wall in plan view which is provided to be erected upwards from the top surface  51   a  of the base  51 . In the example illustrated in  FIG. 5 , the fitting portion  52  has a substantially square shape in plan view. An inner peripheral surface  52   a  of the fitting portion  52  continuously extends from the inner peripheral surface of the base  51 . An air vent groove  54  is formed in an outer peripheral surface  52   b  of the fitting portion  52  along the height direction of the fitting portion  52 . 
         [0039]    In the present exemplary embodiment, the air vent groove  54  is formed over the entire section from the upper end (the distal end) of the fitting portion  52  to the lower end (the proximal end). The lower end (the proximal end) of the fitting portion  52  is an end portion to be coupled to the top surface  51   a  of the base  51 . In the sealing pedestal  5  formed as described above, a hollow portion  55  is formed at the inner periphery side of the fitting portion  52  and the base  51 . The microphone  4  mounted on the control board  3  is disposed in the hollow portion  55 , as illustrated in  FIG. 4 . 
         [0040]    As illustrated in  FIGS. 3 and 4 , a fitted portion  13  is provided on the inner surface  11   b  of the front housing  11  in the housing  10  to protrude from the inner surface  11   b  to the control board  3  and the microphone  4 . The fitted portion  13  is a wall member formed in an annular shape in plan view. An inner peripheral surface  13   a  of the fitted portion  13  is formed in a shape similar to that of the outer peripheral surface  52   b  of the fitting portion  52  in the sealing pedestal  5 , and is designed to be slightly smaller than the outer peripheral surface  52   b.    
         [0041]    In the present exemplary embodiment, when the mobile phone  1  is assembled, the fitting portion  52  in the sealing pedestal  5  is fitted to the fitted portion  13  formed on the inner surface  11   b  of the front housing  11 . As a result, the outer peripheral surface  52   b  of the fitting portion  52  and the inner peripheral surface  13   a  of the fitted portion  13  abut on each other. Accordingly, the microphone chamber  6  is isolated from another space within the housing  10  to seal the microphone  4 . The outer peripheral surface  52   b  of the fitting portion  52  is an example of an abutting surface, and the inner peripheral surface  13   a  of the fitted portion  13  is an example of an abutted surface. 
         [0042]      FIG. 4  illustrates the mobile phone  1  which is completely assembled, in which the microphone  4  is sealed. When the mobile phone  1  is assembled, the front housing  11  and the control board  3  are fastened to each other by a fastening member such as a fixing screw (not illustrated). Here, a mutual position of the fitted portion  13  of the front housing  11  side and the fitting portion  52  of the sealing pedestal  5  side is adjusted so that the positions of the fitted portion  13  and the fitting portion  52  coincide with each other in plain view. 
         [0043]    When a fixing screw is fastened to fix the control board  3  attached with the microphone  4  and the sealing pedestal  5  to the front housing  11 , a compressive force is acted on the sealing pedestal  5 . For example, when the fixing screw is fastened according to a specification and the sealing pedestal  5  is pressurized in the thickness direction by a specified amount, the sealing property (airtightness) of the microphone chamber  6  is ensured. However, when the mobile phone  1  is assembled, the sealing pedestal  5  is compressed, thereby reducing the volume of the microphone chamber  6 . 
         [0044]    In the mobile phone  1  in the present exemplary embodiment, since the waterproof film  21  which covers the microphone sound hole  11   a  does not have an air-permeability, the air (pressure) of the microphone chamber  6  may not escape to the outside through the waterproof film  21 . Here, when the internal pressure of the microphone chamber  6  is excessively increased during the assembly of the mobile phone  1 , the vibration plate of the microphone  4  may be damaged. Therefore, the mobile phone  1  employs a structure in which the air vent groove  54  described above is formed in the sealing pedestal  5  so that the air (pressure) of the microphone chamber  6  may escape to the outside of the microphone chamber  6  through the air vent groove  54  during the assembly of the mobile phone  1 . 
         [0045]    In compression of the sealing pedestal  5 , when the compression rate is set to be excessively high, the repulsive force of the sealing pedestal  5  may be increased, thereby making the sealing degree of the housing  10  incomplete. Therefore, in the sealing pedestal  5  of the present exemplary embodiment, a location of the air vent groove  54  is provided in the fitting portion  52  instead of the base  51 . 
         [0046]      FIG. 7  is a view illustrating the mobile phone  1  which is being assembled.  FIG. 7  illustrates a part of a cross-section passing through the air vent groove  54  of the sealing pedestal  5  in the mobile phone  1 . When the mobile phone  1  is assembled, the fitting portion  52  of the sealing pedestal  5  is fitted to the fitted portion  13  protruding from the inner surface  11   b  of the front housing  11 , as described above. 
         [0047]    Since the inner peripheral surface  13   a  of the fitted portion  13  is designed to be slightly smaller than the outer peripheral surface  52   b  of the fitting portion  52  in the sealing pedestal  5 , the inner peripheral surface  13   a  of the fitted portion  13  and the outer peripheral surface  52   b  of the fitting portion  52  come in contact with each other in a sliding manner and are fitted to each other. 
         [0048]    In the state illustrated in  FIG. 7 , the top surface  51   a  of the base  51  in the sealing pedestal  5  is isolated from a distal end surface  13   b  of the fitted portion  13  in the front housing  11 , and an air vent gap  14  is formed between the top surface  51   a  and the distal end surface  13   b . Accordingly, in that state, the microphone chamber  6  (the hollow portion  55 ) is communicated with the outside through the air vent groove  54  formed in the fitting portion  52  of the sealing pedestal  5  and the air vent gap  14 . Accordingly, during an assembly process of the mobile phone  1 , the microphone  4  may be assembled with the housing  10  while the air of the microphone chamber  6  is purged from the air vent groove  54  (i.e., the pressure is released). 
         [0049]    The dashed arrow in  FIG. 7  conceptually illustrates the flow of air which is released from the inside of the microphone chamber  6  to the outside while the fitting portion  52  of the sealing pedestal  5  is fitted to the fitted portion  13  of the front housing  11 . As described above, according to the assembly method of the mobile phone  1  according to the present exemplary embodiment, it is possible to suppress the pressure within the microphone chamber  6  from increasing when the microphone  4  is assembled. 
         [0050]    As a result, the vibration plate of the microphone  4  may be suppressed from being damaged. When the pressure within the microphone chamber  6  is suppressed from being increased during the assembly of the microphone  4 , a constant displacement may be suppressed from being provided to the vibration plate of the microphone  4 . Accordingly, the manufacturing variations of the microphone  4  may be reduced. 
         [0051]    Meanwhile, while the fitting portion  52  is gradually fitted to the fitted portion  13 , the width of the air vent gap  14  is gradually decreased. At a point of time the distal end surface  13   b  of the fitted portion  13  is abutted on the top surface  51   a  of the base  51  in the sealing pedestal  5 , the width of the air vent gap  14  becomes 0, and the air vent groove  54  is not communicated with the outside of the microphone chamber  6 . Accordingly, as illustrated in  FIG. 4 , the communication state between the inside and outside of the microphone chamber  6  through the air vent groove  54  is interrupted. 
         [0052]    Here, when the fixing screw is fastened to a predetermined position to fix the control board  3  to the front housing  11 , the predetermined fastening amount of the fixing screw is set such that the distal end surface  13   b  of the fitted portion  13  is abutted on the top surface  51   a  of the base  51 , and the fitting portion  52  is compressed slightly in the thickness (height) direction. As a result, while the fitting portion  52  of the sealing pedestal  5  is fitted to the fitted portion  13  of the front housing  11 , the air is suppressed from escaping from the microphone chamber  6  through the air vent groove  54  and the air vent gap  14 . Accordingly, when the assembly of the microphone  4  is completed, the microphone chamber  6  may be placed in a sealed state so as to satisfactorily ensure a sound insulation of the microphone chamber  6 . As a result, the sensitivity of the microphone  4  may be improved. 
         [0053]    Here, in the sealing pedestal  5  of the present exemplary embodiment, the top surface  51   a  of the base  51  is a smooth surface. Also, the distal end surface  13   b  of the fitted portion  13  protruding from the inner surface  11   b  of the front housing  11  is also a smooth surface. Accordingly, when the fitting portion  52  of the sealing pedestal  5  is fitted to the fitted portion  13 , the distal end surface  13   b  of the fitted portion  13  and the top surface  51   a  of the base  51  may be parallel to each other and both surfaces may be brought into contact with each other. 
         [0054]    As a result, the distal end surface  13   b  of the fitted portion  13 , in its entirety, may uniformly come in contact with the top surface  51   a  of the base  51  in the sealing pedestal  5 . Accordingly, when the microphone  4  is completely assembled with the front housing  11 , the airtightness of the microphone chamber  6  is ensured. Since the fitting portion  52  of the sealing pedestal  5  and the fitted portion  13  protruding from the inner surface  11   b  of the front housing  11  are annularly formed, the airtightness of the microphone chamber  6  may be easily ensured when the assembly of the microphone  4  is completed. 
         [0055]    According to the present exemplary embodiment, when the fitting portion  52  of the sealing pedestal  5  is fitted to the fitted portion  13  provided in the front housing  11 , the distal end surface  13   b  of the fitted portion  13  comes in close contact with the base  51  of the sealing pedestal  5 , thereby ensuring the airtightness of the microphone chamber  6 . That is, even when the base  51  of the sealing pedestal  5  is not excessively compressed, the airtightness of the microphone chamber  6  may be ensured. Therefore, it is possible to suppress the repulsive force caused by the compression of the sealing pedestal  5  from excessively increasing, where the repulsive force is acting in a direction in which the control board  3  is separated from the inner surface  11   b  of the front housing  11 . 
         [0056]    Accordingly, when the mobile phone  1  is assembled, the sealing of the housing  10  may be suppressed from being incomplete. In a state where the fitting portion  52  of the sealing pedestal  5  is fitted to the fitted portion  13 , the outer peripheral surface  52   b  of the fitting portion  52  pressurizes the inner peripheral surface  13   a  of the fitted portion  13 . In this manner, when the outer peripheral surface  52   b  of the fitting portion  52  and the inner peripheral surface  13   a  of the fitted portion  13  come in close contact with each other, the sealing property and the sound insulation of the microphone chamber  6  may be improved. Since the fitting portion  52  is fitted to the fitted portion  13 , the sealing property of the microphone chamber  6  may be suitably ensured due to a horizontal stress acting between the fitting portion  52  and the fitted portion  13 . 
         [0057]    As described above, according to the mobile phone  1  in the present exemplary embodiment, the microphone  4  may be assembled with the housing  10  while allowing the air to escape from the microphone  4 . Thus, the damage to the microphone  4  may be suitably suppressed. Also, when the microphone  4  is assembled, communication between the inside and the outside of the microphone chamber  6  is interrupted. Thus, the airtightness of the microphone chamber  6  may be ensured so that the mobile phone  1  having the microphone  4  with an increased sensitivity state may be provided to a user. Further, a plurality of air vent grooves  54  may be provided in the fitting portion  52 . 
       Modified Example 
       [0000]    
       
         
           
             Modified examples of the mobile phone  1  will be described.  FIG. 8  is a view explaining the mobile phone  1  according to a modified example 1. For example, in the sealing pedestal  5  illustrated in  FIG. 8 , the top end of the outer peripheral surface  52   b  in the fitting portion  52  is formed into a round shape (an R shape). In this manner, the fitting portion  52  of the sealing pedestal  5  may be easily fitted to the fitted portion  13  of the front housing  11 . That is, the fitting easiness of the fitting portion  52  in the sealing pedestal  5  may be improved. The top end of the outer peripheral surface  52   b  in the fitting portion  52  may be obliquely cut into a chamfered shape. In this case, the same effect as that in the case where the top end is formed into the round shape may be achieved. 
           
         
       
     
         [0059]      FIG. 9  is a view explaining the mobile phone  1  according to a modified example 2. As illustrated in  FIG. 9 , the outer peripheral surface  52   b  of the fitting portion  52  of the sealing pedestal  5  may be formed into a tapered shape such that its distal end portion becomes thinner from the bottom side to the top side. Accordingly, the fitting easiness of the fitting portion  52  with respect to the fitted portion  13  may be improved. 
         [0060]      FIG. 10  is a view explaining the mobile phone  1  according to a modified example 3. As illustrated in  FIG. 10 , the fitted portion  13  protruding from the front housing  11  may be formed into a reversed-tapered shape such that its lower side is gradually broaden from the proximal end to the distal end. Accordingly, the fitting portion  52  of the sealing pedestal  5  may be easily fitted to the fitted portion  13 . Each of  FIGS. 8 to 10  as described above corresponds to  FIG. 7 , and illustrates the mobile phone  1  which is being assembled. That is, the drawings illustrate the mobile phone  1  during the process of fitting the fitting portion  52  of the sealing pedestal  5  fixed to the control board  3  mounted with the microphone  4 , to the fitted portion  13  of the front housing  11 . Each of  FIGS. 8 to 10  illustrates, as in  FIG. 7 , a part of a cross-section passing through the air vent groove  54  of the sealing pedestal  5  in the mobile phone  1 . 
         [0061]    In the exemplary embodiment 1, the air vent groove  54  is formed on the outer peripheral surface  52   b  of the fitting portion  52  in the sealing pedestal  5 . However, the air vent groove  54  may be formed on the inner peripheral surface  13   a  of the fitted portion  13  at the front housing  11  side. In this case as well, the pressure of the microphone chamber  6  may escape through the air vent groove  54  until the distal end surface  13   b  of the fitted portion  13  is in close contact with the top surface  51   a  of the base  51  in the sealing pedestal  5 . In the fitted portion  13 , a plurality of air vent grooves  54  may be provided. 
         [0062]    In the exemplary embodiment 1, the fitting portion  52  in the sealing pedestal  5  is internally fitted to the fitted portion  13  in the front housing  11 , but the present disclosure is not limited thereto.  FIG. 11  is a view explaining the mobile phone  1  according to a modified example 4.  FIG. 11  illustrates a part of a cross-section passing through the air vent groove  54  in the sealing pedestal  5  in the mobile phone  1 . For example, as illustrated in  FIG. 11 , the fitting portion  52  in the sealing pedestal  5  may be externally fitted to the fitted portion  13 . 
         [0063]    In the example illustrated in  FIG. 11 , the fitting portion  52  in the sealing pedestal  5  is externally fitted to the fitted portion  13  of the front housing  11 , and the inner peripheral surface  52   a  of the fitting portion  52  is abutted on and is in close contact with an outer peripheral surface  13   c  of the fitted portion  13 . In this case, the air vent groove  54  may be formed on the inner peripheral surface  52   a  of the fitting portion  52  or on the outer peripheral surface  13   c  of the fitted portion  13 . Accordingly, the pressure of the microphone chamber  6  may escape through the air vent groove  54  until the distal end surface  13   b  of the fitted portion  13  is in close contact with the top surface  51   a  of the base  51  in the sealing pedestal  5 . 
         [0064]    In the modified example illustrated in  FIG. 11 , the outer peripheral surface  13   c  of the fitted portion  13  may be designed to be slightly larger than the inner peripheral surface  52   a  of the fitting portion  52  in the sealing pedestal  5 . Accordingly, when the fitting portion  52  of the sealing pedestal  5  is externally fitted to the fitted portion  13 , the outer peripheral surface  13   c  of the fitted portion  13  is fastened from the outside by the inner peripheral surface  52   a  of the fitting portion  52 , thereby improving adhesion between them. 
         [0065]    In the modified example 4 illustrated in  FIG. 11 , the inner peripheral surface  52   a  of the fitting portion  52  is an example of an abutting surface, and the outer peripheral surface  13   c  of the fitted portion  13  is an example of an abutted surface. As in the modified example 4, in a case where the fitting portion  52  of the sealing pedestal  5  is externally fitted to the fitted portion  13 , the air vent groove  54  may be formed at the fitted portion  13  side as well. In such a case, the air vent groove  54  may be formed on the outer peripheral surface  13   c  of the fitted portion  13 , the outer peripheral surface  13   c  being abutted on the inner peripheral surface  52   a  of the fitting portion  52  when the fitting portion  52  is externally fitted to the fitted portion  13 . Accordingly, the pressure of the microphone chamber  6  may escape through the air vent groove  54  until the distal end surface  13   b  of the fitted portion  13  is in close contact with the top surface  51   a  of the base  51  in the sealing pedestal  5 . 
         [0066]    In the exemplary embodiment 1, the sealing pedestal  5  is fixed to the control board  3 , but the present disclosure is not limited thereto.  FIG. 12  is a view explaining the mobile phone  1  according to a modified example 5.  FIG. 12  illustrates a part of a cross-section passing through the air vent groove  54  of the sealing pedestal  5  in the mobile phone  1 . For example, as illustrated in  FIG. 12 , the sealing pedestal  5  may be directly fixed to the microphone  4 . 
         [0067]    The sealing pedestal  5  illustrated in  FIG. 12  seals the microphone chamber  6  which the vibration plate of the microphone  4  faces by isolating the microphone chamber  6  from another space within the housing  10 . The structure of the sealing pedestal  5  according to the present modified example is the same as that of the sealing pedestal  5  according to the exemplary embodiment 1. The sealing pedestal  5  is fitted to the fitted portion  13  provided in the front housing  11  when the microphone  4  is assembled with the front housing  11 . Each of  FIGS. 11 and 12  described above corresponds to  FIG. 4 , and illustrates a state where the mobile phone  1  is completely assembled. 
         [0068]    In the exemplary embodiment and modified examples as described above, the air vent groove  54  is provided in the fitting portion  52  of the sealing pedestal  5  or in the fitted portion  13 . Alternatively, a (lateral) groove or a (lateral) hole which crosses the fitting portion  52  may be provided.  FIG. 13  is a view explaining the mobile phone  1  according to a modified example 6.  FIG. 14  is a view explaining the mobile phone  1  according to a modified example 7. Each of  FIGS. 13 and 14  corresponds to  FIG. 4 , and illustrates a state where the mobile phone  1  is completely assembled. In the sealing pedestal  5  illustrated in  FIG. 13 , a lateral groove  54 A crossing the fitting portion  52  is formed on the fitting portion  52 . 
         [0069]      FIG. 13  illustrates a part of a cross-section passing through the lateral groove  54 A of the sealing pedestal  5  in the mobile phone  1 . In the sealing pedestal  5  illustrated in  FIG. 14 , a lateral hole  54 B crossing the fitting portion  52  is formed on the fitting portion  52 .  FIG. 14  illustrates a part of a cross-section passing through the lateral hole  54 B of the sealing pedestal  5  in the mobile phone  1 . Even when the lateral groove  54 A or the lateral hole  54 B is provided in the fitting portion  52  of the sealing pedestal  5  as illustrated in  FIGS. 13 and 14 , the same effect as in the case where the air vent groove  54  is provided may be achieved. 
         [0070]    That is, the sealing property of the microphone chamber  6  is ensured by the fitted portion  13  (not having an air vent groove) while the sealing pedestal  5  is fitted to the fitted portion  13 . More specifically, when the distal end surface  13   b  of the fitted portion  13  is abutted on the top surface  51   a  of the base  51  in the sealing pedestal  5 , the communication with the inside of the microphone chamber  6  via the lateral groove  54 A ( FIG. 13 ) or the lateral hole  54 B ( FIG. 14 ) is restricted, thereby ensuring the sealing property of the microphone chamber  6 . In the structure described in the examples illustrated in  FIGS. 13 and 14 , the fitting portion  52  in the sealing pedestal  5  is internally fitted to the fitted portion  13 . However, the structure may also be applied to a case where the fitting portion  52  is externally fitted to the fitted portion  13 . That is, the lateral groove  54 A or the lateral hole  54 B may be provided to cross the fitting portion  52  which is externally fitted to the fitted portion  13 . 
         [0071]    In the example illustrated in  FIG. 13 , the lateral groove  54 A is provided in the fitting portion  52  of the sealing pedestal  5 , but may be provided in the fitted portion  13 . In the example illustrated in  FIG. 14 , the lateral hole  54 B is provided in the fitting portion  52  of the sealing pedestal  5 , but may be provided in the fitted portion  13 . When the lateral groove  54 A or the lateral hole  54 B is provided at the fitted portion  13  side as described above, the sealing property of the microphone chamber  6  is ensured by the fitting portion  52  of the sealing pedestal  5  (which does not have the lateral groove  54 A or the lateral hole  54 B) while the sealing pedestal  5  is fitted to the fitted portion  13 . 
         [0072]    More specifically, when the distal end surface  13   b  of the fitted portion  13  is abutted on the top surface  51   a  of the base  51  in the sealing pedestal  5 , the communication with the inside of the microphone chamber  6  via the lateral groove or hole of the fitted portion  13  is restricted, thereby ensuring the sealing property of the microphone chamber  6 . The above described structure in which the lateral groove  54 A or the lateral hole  54 B is provided in the fitted portion  13  is not limited to the case where the fitting portion  52  of the sealing pedestal  5  is internally fitted to the fitted portion  13 , but also may be applied to the case where the fitting portion  52  is externally fitted to the fitted portion  13 . 
         [0073]    The above described exemplary embodiment may be modified in various ways without departing from the scope of the present disclosure. Further, the exemplary embodiment and modified examples as described above may be implemented in combination as much as possible. For example, in the exemplary embodiment as described above, the sealing pedestal  5  is employed to seal the microphone  4 , but the present disclosure is not limited thereto. For example, the sealing pedestal  5  may be used to seal the speaker as an example of an acoustic component. Also, in the exemplary embodiment as described above, the mobile phone is employed as an example of an electronic device, but the present disclosure may be applied to other electronic devices such as a notebook computer or a tablet computer. 
         [0074]    All examples and conditional language recited herein are intended for pedagogical purposes to aid the reader in understanding the invention and the concepts contributed by the inventor to furthering the art, and are to be construed as being without limitation to such specifically recited examples and conditions, nor does the organization of such examples in the specification relate to a showing of the superiority and inferiority of the invention. Although the embodiments of the present invention have been described in detail, it should be understood that the various changes, substitutions, and alterations could be made hereto without departing from the spirit and scope of the invention.