Abstract:
A method of tracking and acting on events related to the delivery of a mail piece is provided. An integrated record associated with an addressee of a mail piece is created. The mail piece is given a unique identifier, is associated with the addressee, and is placed in a mail stream with the date and nature of associated delivery events being recorded. After a predetermined delivery event occurs, a follow-up communication is transmitted to the addressee, and the date of this follow-up communication is recorded. The date of any response by the addressee to the follow-up communication is also recorded. To the integrated record associated with the addressee is added the date and nature of the delivery events associated with the mail piece, the date of the follow-up communication, and the date of any response by the addressee to the follow-up communication.

Description:
BACKGROUND OF THE INVENTION 
     The present invention relates generally to a socket for a module, and more particularly to a socket of improved connection reliability. 
     Conventionally, sockets have been used to mount camera modules, which integrates an image pickup device such as a CCD (Charge Coupled Device), a CMOS (Complementary Metal Oxide Semiconductor) image sensor, or the like, and an optical element such as a lens, on a substrate of a small electronic device such as a cellular telephone, a PDA (Personal Digital Assistant), or the like. One such structure is described in Japanese Patent Application Laid-Open (Kokai) Publication No. 2003-91685). 
       FIG. 10  is a cross-sectional view of such a conventional camera module socket. 
       801  denotes the socket housing for a module, while  802  denotes the camera module, which is received in the socket housing  801 . Also, two sets of locking devices  804  are provided on the inner surfaces of facing sidewalls of the socket housing  801  and engage locking surfaces  810  formed on the shoulder portions of the camera module  802  for locking the camera module  802  in place. 
     Each set of locking devices  804  include locking elements  805  and  806  having different heights. This is an arrangement to deal with the fact that a small module  802   a  having a relatively small outer dimension and a large module  802   b  having a relatively large outer dimension exist in the same kind of camera modules  802  due to dimensional errors in manufacturing. In the case of the small module  802   a , the locking element  806  located at a lower position engages the locking surface  810 , and in the case of the large module  802   b , the locking element  805  located at a higher position engages the locking surface  810 . 
     In addition, connection terminals  807  are provided on the bottom of the socket and protrude upward from the bottom  808  due to their spring property in order to contact members formed on the bottom of the camera module  802 . Then, the height of protrusion of the connection terminal  807  must be lesser for the small module  802   a , larger for the large module  802   b.    
     However, in the conventional socket for a module, two locking positions are provided by means of locking elements  805  and  806  which deal with variations of the contact force of the connection terminal  807  due to a change in the height of protrusion of the connection terminal  807  caused by dimensional errors in manufacturing of the modules  802 . In order to provide a plurality of locking positions in this way, the shape of the locking elements  805  and  806  and the structure of the module socket are complicated. A structure to obtain more stable contact is not sufficiently considered. Therefore, the contacting state between the connection terminal  807  and the contact member formed on the bottom of the camera module  802  becomes unstable. Also, the contact between the connection terminal  807  and the contact member formed on the bottom of the module  802  cannot be reliably maintained when the socket receives an impact from the outside due to any cause which may occur. 
     SUMMARY OF THE INVENTION 
     The present invention has been made taking the foregoing problems of the above-described conventional socket for a module into consideration and an object of the present invention is to provide a module socket, with a lesser number of parts, with a low cost due to decrease of the number of assembling steps, a stable contact force of terminals, reliably maintains a contact state with contact members of a module, and has a strong locking function for the module, and prevents slipping off of the module, by dividing terminals provided in a housing into upper and lower contacting portions for contacting contact members formed on the bottom of the module. 
     Therefore, a socket for a camera module, according to the present invention, includes: a housing member made of an insulating material and side walls defining the sides of the module; a plurality of terminals provided in the housing member; and elastic engagement (or locking) elements extending inward from the side walls for securing the module at a predetermined position in the insertion direction wherein each of the terminals comprises cantilever-like first and second contact arm portions with respective first and second contacting portions formed thereon for contacting contact members on the bottom of the module, and wherein the upper end of the first contacting portion is disposed higher than the upper end of the second contacting portion, in the state in which the module is not inserted in the socket. 
     In another module socket according to the present invention, the first or second contacting portions elastically contact the contact members and applies an upward force to the module, when the module is inserted in a predetermined position. 
     In a further socket according to the present invention, the position of the upper end of the first contacting portion and the position of the upper end of the second contacting portion are determined so as to correspond respectively lower limit and upper limit of the dimensional errors of the module. 
     In a still further socket of the present invention, the first and second contacting portions of each terminal are provided for the same contact member on the module. 
     In a further socket according to the present invention, the first and second contacting portions of each terminal project higher than the bottom plate portion, when the module is inserted in the socket. 
     In a still further socket according to the present invention, the module is provided with engagement shoulder portions on its sides, and is sandwiched and held vertically by elastic engagement elements engaging upper surfaces of the engagement shoulder portions, and the first or second contacting portions contacting the contact members, in the state in which the module is inserted in a predetermined position. 
     According to the present invention, the terminals provided in the housing are divided into upper and lower contacting portions for contacting contact members formed on the bottom of the module. Therefore, it is possible to provide a socket with a lesser number of parts, a low cost due to decrease of the number of assembling steps, a stable contact force for its terminals, which reliably maintains a contact state with contact members of the module, has a strong function to lock the module, and can prevent slipping off of the module. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a perspective view of a socket according to one embodiment of the present invention; 
         FIG. 2  is an exploded view of the socket of  FIG. 1 ; 
         FIG. 3  is a cross-sectional view of the socket of  FIG. 1 , taken along line A-A thereof; 
         FIG. 4  is an enlarged view of the major part of the socket of the present invention, showing the portion B; 
         FIG. 5  is a perspective view of a terminal used with sockets of the present invention; 
         FIG. 6  is a side view of the terminal of  FIG. 5 ; 
         FIG. 7  is a perspective view showing the positional relation between the module and the socket before being mounted therein; 
         FIG. 8  is a perspective view of the socket after receiving the module therein; 
         FIG. 9  is a cross-sectional view of  FIG. 8  after mounting the module therein, taken along the line C-C thereof; and 
         FIG. 10  is a cross-sectional view of a conventional camera module socket. 
     
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENTS 
       FIG. 1  is a perspective view of a socket according to an embodiment of the present invention, and reference numeral  1  denotes a socket for a module constructed in accordance with the principles of the present invention, which is used for electrically connecting a camera module  101  to a substrate  91 . The camera module  101  preferably integrates an image pickup device such as a CCD, a CMOS image sensor, or the like and an optical element such as a lens. However, the module  101  may be any kind of module including a sensor module such as an infrared sensor or finger print reading sensor or acoustic element module such as a microphone. The socket  1  is used for mounting the module  101  in a small electronic device such as a cellular telephone, a PDA, or the like, but the socket  1  may also be used for mounting the module in a household electrical appliance such as a TV set, a washing machine, and a refrigerator, a monitor for security, and an automobile or the like. The socket  1  is mounted on the substrate  91  such as a printed circuit board and the substrate  91  may be made of any material, rigid or flexible. 
     In addition, in this embodiment, representations of directions such as up, down, left, right, front, rear, and the like, used for explaining the structure and movement of each portion of the socket  1 , and the like, are not absolute, but relative. These representations are appropriate when the socket  1  is in the position shown in the figures. If the position of the socket  1  changes, it is assumed that these representations are to be changed according to the change of the position of the socket  1  or its constituent portion. 
     As shown in  FIG. 2 , the socket  1  has a housing member  11  that accommodates the module  101  therein, terminals  61  disposed in the housing member  11 , and a shell  71  attached to the housing member  11 . The socket  1  is provided with the shape of a container with a bottom having an open end. Further, in the illustrated example, the shell  71  is made of two portions, namely, a first shell  71   a  and a second shell  71   b , but, the shell  71  may be formed as a single member. This description, the first and second shell  71   a ,  71   b  will be explained collectively as the shell  71 . Further, the present embodiment will be described with reference to the case in which the socket  1  has the shape of a container with a bottom, which is approximately rectangular with one end surface being closed, and the other end surface being opened. 
     The housing member  11  is a hollow rectangular plate-like member, which is formed by an insulating material such as a synthetic resin, and has a bottom plate portion  17  and four side walls  16  extending upwardly from the bottom plate portion  17  to define an interior cavity and to surround the side surfaces of the module  101 . 
     The first shell  71   a  and second shell  71   b  are attached to the side walls  16 . A plurality of conductive terminals  61  are attached in parallel, to each of the lower end portions of a pair of facing inner surfaces of the side walls  16 . A plurality of terminal mounting concave portions, or recesses,  35  are formed in parallel in each of the lower end portions of the pair of inner surfaces of the side walls  16  for arranging the terminals  61  in the lower end portions of the pair of inner surfaces. The terminals  61  are loaded in the terminal mounting concave portions  35  one by one. A base portion  63  of the terminal  61  is housed in the terminal mounting concave portion  35  and fixed thereto. Here, the number and the arrangement of the terminals  61  and the terminal mounting concave portions or recesses  35  may be appropriately decided to fit the module. 
     The bottom plate portion  17  corresponds to the bottom of the socket and the bottom plate portion  17  has a rectangular shape with a width narrower than that of the bottom, and terminal accommodating openings  18  are formed on either side of the bottom plate portion  17 . The terminal openings  18  correspond to the terminals  61  attached to the lower end portions of a pair of facing inner surfaces of the side walls  16 . Further, the terminal accommodating opening  18  is formed in such a size as to accommodate a contact arm portion  68  of the terminal  61 . 
     Engagement projections  15  are formed on the outer surfaces of the side walls  16 , and engagement openings  74  are formed in the metal shell  71  that engage with the engagement projections  15 . Therefore, the metal shell  71  is prevented from being detached from the side walls  16 . In addition, a polarizing groove  37  in the form of a slit is formed in one side wall  16 , into which a polarizing key  115  of the module  101  is inserted. The upper end portions of the inner surfaces of the side walls  16  have first engagement concave portions  34 , second engagement concave portions  32 , locking spring member concave portions  31 , and grounding spring member concave portions  33 , formed therein which correspond to first engagement portions  75 , second engagement portions  76 , locking spring members  77  and grounding spring members  78  of the metal shell  71 . 
     Each of the first shell  71   a  and second shell  71   b  stamped and formed from a metal block. Then the first engagement portions  75 , the second engagement portions  76 , the locking spring members  77 , and grounding spring members  78  are formed by inwardly bending them from the upper edge of the body of the metal shell  71  inwardly and downwardly along the upper edge. Here, the first engagement portions  75  and the second engagement portions  76  extend downward approximately parallel with the body of the shell  71  and are accommodated in the first engagement concave portions  34  and the second engagement concave portions  32  in the inner surfaces of the side walls  16 . The second engagement portions  76  extend to a position lower than the first engagement portions  75 , and the projections formed on the both sides of the second engagement portions  76  bite into the both side surfaces of the second engagement concave portions  32  to engage with the second engagement concave portions  32  of the housing. 
     In addition, the locking spring members  77  and the grounding spring members  78  are elongated members in the form of tangs that extend to a position lower than the second engagement portions  76  and are inclined toward the center of the socket so that the lower ends thereof being free lower ends. Further, the grounding spring members  78  are arranged on the all side surfaces of the side walls  16 , while the locking spring members  77  are arranged only on a pair of inner surfaces of the side walls  16  in which the terminals  61  are arranged. 
     The leading end of the free end portion of each locking spring member  77  is largely curved outward and becomes approximately horizontal. ( FIG. 3 ) Thereby, when mounting the module  101 , the curved surfaces of the free ends of the locking spring members  77  contact the side surfaces of the module  101 , so that the side surfaces of the module  101  smoothly move without resistance even if the side surfaces of the module  101  move while contacting the free end portions of the locking spring members  77 . The leading ends of the free end portions of the locking spring members  77  engage with the upper surface of an engagement shoulder portion  117  ( FIG. 7 ) of the module  101  and the leading ends of the free end portions of the locking spring members  77  are horizontal, and as a result, the engagement of the leading ends of the free end portions of the locking spring member  77  with the upper surface of the engagement shoulder portion  117  becomes reliable and the leading ends of the free end portions of the locking spring member  77  are not detached from the upper surface of the engagement shoulder portion  117 . 
     The leading ends of the free end portions of the grounding spring member  78  are slightly curved downward and become approximately vertical. Thereby, when mounting the module  101 , the curved surface of the free end portions contact the side surface of the module  101 , so that the side surface of the module  101  can smoothly move without receiving a resistance even if the side surface of the module  101  moves while contacting the free end portions of the grounding spring member  78 . 
     A plurality of lower side projections  79  extend downward and are connected to the lower edge of the body of the shelf  71 . The lower ends of the lower side projections  79  are connected to shell connection pads  93  exposed to the surface of the substrate  91  by means such as soldering. The shell connection pads  93  are connected to grounding traces or the like (not illustrated), the metal shell  71  has the same potential as that of the ground traces by connecting the lower side projections  79  to the shell connection pads  93 , whereby the metal shell  71  functions as an electromagnetic shield. 
     Terminal connection pads  92  are also exposed on the surface of the substrate  91  ( FIG. 8 ). A tail portion  62  of each terminal  61  is connected to the terminal connection pad  92  by soldering. The terminal connection pads  92  are connected to signal traces and/or power traces or the like (not illustrated). 
       FIG. 3  is a cross sectional view of the socket according to the embodiment of the present invention, taken along the line A-A of  FIG. 1 ,  FIG. 4  is an enlarged view of the major part of the socket according to the embodiment of the present invention, showing the portion B of  FIG. 1 ,  FIG. 5  is a perspective view of the terminal according to the embodiment of the present invention, and  FIG. 6  is a side view of the terminal according to the embodiment of the present invention. 
     As shown in  FIG. 5 , the terminal  61  is formed by punching a metal plate and bending the plate, and the terminal  61  has a base portion  63 , a tail portion  62 , a curved portion  63   a , a contacting portion  64 , a leading end portion  65 , a body portion  66 , a contact arm portion  68  and an arm connecting portion  69 . The base end  63  vertically extends and the horizontal tail portion  62  is connected to the lower end of the base portion  63 , while being bent approximately at a right angle. Projecting portions  63   b  are formed on the opposite sides of the base portion  63  so as to engage or bite into the opposite end surfaces of the terminal mounting concave portion  35 . 
     The body portion  66  is a vertically extending flat member, and its upper end is integrally connected to the upper end of the base portion  63  via the curved portion  63   a.  The curved portion  63   a  is a portion which is bent over approximately 180 degrees, and as shown in  FIGS. 3 and 6 , the side surfaces of the continuous base portion  63 , curved portion  63   a , and body portion  66  form approximately a U-shape. The body portion  66  is approximately flush with the inner surface of the side wall  16  of the housing member  11  when the terminals  61  are fixed to the terminal mounting concave portion  35 , as shown in  FIGS. 3 and 4 . 
     On the other hand, the contact arm portion  68  is connected to the lower end of the body portion  66  via the arm connecting portion  69 . The arm connecting portion  69  is a portion which is preferably curved not less than 90 degrees, so that the contact arm portion  68  extends obliquely upward from the lower end of the body portion  66 , as shown in  FIGS. 3 and 6 . The contacting portion  64  bulging upward is formed on the free end of the contact arm portion  68  and the leading end portion  65  of the contact arm portion  68  continued to the contacting portion  64  is faced downward. Therefore, when the module  101  is not mounted, the contact arm portion  68  projects upward from the upper surface of the bottom plate portion  17  of the housing member  11 , and the upper end of the contacting portion  64  is spaced apart from and upward from the upper surface of the bottom plate portion  17 . The body portion  66 , the arm connecting portion  69  and the contact arm portion  68  are elastic, and when the module  101  is mounted in the socket, the contacting portion  64  located at the free end of the cantilever-like or cantilever-shaped contact arm portion  68  is pressed downward by the bottom surface of the module  101  and is elastically deformed so that a repulsion force is generated. The contacting portion  64  is urged upward due to this repulsion force and pressed against the contact member formed on the bottom surface of the module  101 . This makes it possible to reliably maintain contact between the terminal contacting portions  64  and the contact members of the module  101 . Where the contacting portion  64  is pressed downward by the bottom surface of the module  101 , the contact arm portion  68  becomes approximately parallel with the upper surface of the substrate  91  and is accommodated in the terminal accommodating opening  18 , and the contact arm portion  68  is positioned at a position lower than the upper surface of the bottom plate portion  17 , except for the contacting portion  64 . 
     In the present embodiment, a slit  67  is formed in the terminal  61  ( FIG. 5 ), so that the contacting portion  64 , the leading end portion  65 , the body portion  66 , the contact arm portion  68  and the arm connecting portion  69  are divided by this slit  67  into left and right, first and second contacting portions  64   a  and  64   b , first and second leading end portions  65   a  and  65   b , first and second body portions  66   a  and  66   b , first and second contact arm portions  68   a  and  68   b , and first and second arm connecting portions  69   a  and  69   b , respectively. Here, when the first and second contacting portions  64   a  and  64   b , the first and second leading end portions  65   a  and  65   b , the first and second body portions  66   a  and  66   b , the first and second contact arm portions  68   a  and  68   b , and the first and second arm connecting portions  69   a  and  69   b  are explained in an integrated manner, respectively, as described above, they will be explained as the contacting portion  64 , the leading end portion  65 , the body portion  66 , the contact arm portion  68 , and the arm connecting portion  69 . 
     The slit  67  as shown in  FIG. 5  starts from the middle of the body portion  66 , however, the length of the slit  67  can be changed appropriately. The slit  67  may be formed at least in the range of the contacting portion  64 , the leading end portion  65 , the contact arm portion  68 , and the arm connecting portion  69 , and not in the body portion  66  or the slit  67  may start from the upper end of the body portion  66  variations of this structure are contemplated. 
     The degree of curvature of the first arm connecting portion  69   a  is larger than that of the second arm connecting portion  69   b , and the angle between the first body portion  66   a  and the first contact arm portion  68   a  is smaller than the angle between the second body portion  66   b  and the second contact arm portion  68   b.  In other words, the first contact arm portion  68   a  is inclined with respect to the upper surface of the bottom plate portion  17  more largely as compared to the second contact arm portion  68   b.  The position of the upper end of the first contacting portion  64   a  is separated from the upper surface of the bottom plate portion  17  upward more largely as compared to the position of the upper end of the second contacting portion  64   b.    
     The degree of curvature of the first arm connecting portion  69   a  and the degree of curvature of the second arm connecting portion  69   b  are determined so that the position of the upper end of the first contacting portion  64   a  and the position of the upper end of the second contacting portion  64   b  correspond to respective lower limits and upper limits of the manufacturing tolerances, of the module  101 . The position of the upper end of the first contacting portion  64   a  is determined to have such a height that reliable contact between the first contacting portion  64   a  and the contact member of the module  101  can be maintained, and the height positions of two contact portions have a difference between the maximum and minimum dimensions in the range of the manufacturing tolerance of the module  101  so that even if the distance between the upper surface and the bottom surface of the engagement shoulder portion  117  of the module  101  is equal to the lower limit of tolerance. 
     The height of the upper surface of the engagement shoulder portion  117  of the module  101  is limited by engaging with the leading end of the free end portion of the locking spring member  77 . Thus if the distance between the upper surface and the bottom surface of the engagement shoulder portion  117  is small, the bottom surface is located at a higher position, and if the distance between the upper surface and the bottom surface of the engagement shoulder portion  117  is large, the bottom surface is located at a lower position. Because the body portion  66 , the contact arm portion  68 , and the arm connecting portion  69  of the terminal  61  are elastically deformed, the contacting portion  64  is vertically displaced and follows the bottom surface of the module  101  by an elastic repulsion force generated by the body portion  66 , arm connecting portion  69 , and the contact arm portion  68  and it maintains control pressure against the contact member on the bottom surface of the module  101 , even if the height of the bottom surface of the module  101  is varied but it is in a predetermined range. If the range of variation in the height of the bottom surface of the module  101  is larger than such a range that the body portion  66 , the arm connecting portion  69 , and the contact arm portion  68  can generate a sufficient repulsion force, the contacting portion  64  is not pressed against the contact member formed on the bottom surface and this makes it impossible to maintain contact between the contacting portion  64  and the contact member. In addition, if the height of the bottom surface of the module  101  is too low, the body portion  66 , the arm connecting portion  69 , and the contact arm portion  68  are deformed exceeding the range of their elastic deformation and they may be plastically deformed. Then, the body portion  66 , the arm connecting portion  69 , and the contact arm portion  68  cannot be elastically deformed again. 
     Therefore, in the present invention, by determining the degree of curvature of the first arm connecting portion  69   a  and the degree of curvature of the second arm connecting portion  69   b  so that the positions of the upper ends of the first and second contacting portions  64   a  and  64   b  correspond to the lower limit and the upper limit of the tolerance, respectively, the position of the bottom surface of the module  101  resides in such a range that the first body portion  66   a , the first arm connecting portion  69   a , and the first contact arm portion  68   a  can generate a sufficient repulsion force even if the distance between the upper surface and the bottom surface of the engagement shoulder portion  117  of the module  101  is in the range near the minimum value, and the position of the bottom surface of the module  101  resides in such a range that the second body portion  66   b , the second arm connecting portion  69   b , and the second contact arm portion  68   b  can generate a sufficient repulsion force even if the distance between the upper surface and the bottom surface of the engagement shoulder portion  117  of the module  101  is in the range near the maximum value. At least one or both of the first contacting portion  64   a  and the second contacting portion  64   b  will reliably maintain contact with the contact member formed on the bottom surface even if there is a variation in the dimension of the module  101 . 
       FIG. 7  is a perspective view showing a positional relation between the module and the socket before being mounted according to the embodiment of the present invention. 
     The substrate  91  has signal and power traces (not shown) which are connected to the terminal connection pads  92 , which are exposed to the upper surface at least in the region where the socket  1  is attached, so that it is possible to connect the terminals  61  of the socket  1  to the connection pads  92  by soldering or the like. The lower surfaces of the tail portions  62  of the terminals  61  are also connected to the connection pads  92  by soldering. The metal shell connection pads  93  for attaching the shell  71  are arranged on the surface of the substrate  91  so that the lower side projections  79  of the shell  71  can be connected to the connection pads  93  by soldering. At least some of shell connection pads  93  are connected to ground traces of the substrate  91 . 
     In attaching the socket  1  to the substrate  91  by soldering, a paste type solder is applied to the upper surfaces of the terminal connection pads  92  and the shell connection pads  93 , and soldering is then performed by reflowing the solder. The socket  1  is placed on the substrate  91  so that the corresponding tail portions  62  of the terminals  61  and the corresponding lower side projections  79  of the shell  71  are positioned on the terminal connection pads  92  and the shell connection pads  93 . Then, soldering is carried out by heating and reflowing the solder in a heating furnace or the like. 
     Before the module  101  is mounted, the free ends of the contact arm portions  68  of the terminals  61  are largely protruding upward from the upper surface of the bottom plate portion  17  of the housing member  11 , as shown in  FIG. 4 . In this case, it can be seen that the first contact arm portions  68   a  are inclined more largely than the second contact arm portions  68   b  and the upper ends of the first contacting portions  64   a  are located higher than the upper ends of the second contacting portions  64   b.  The free ends of the locking spring members  77  and the grounding spring members  78  are protruding from the inner surface of the side walls  16  of the housing member  11  inward largely. 
     The module  101  is inserted in the housing member  11  as shown in  FIG. 7 , and mounted on the socket  1  as shown in  FIGS. 8 and 9 . The module  101  has an upper portion  112  in the shape of approximately a circular column and a lower portion  111  in the shape of approximately a rectangular solid. A polarizing key  115 , which vertically extends and projects, is formed on one side surface of the lower portion  111  and is received in the polarizing groove  37  formed in the side wall  16  of the housing member  11 . 
     The lower halves of a pair of opposite side surfaces of the lower portion  111  are formed as bulging portion  116  that extends outwardly, and the engagement shoulder portion  117  is formed on the boundary between the upper half of the side surface and the side surface of the bulging portion  116 . The upper surface of the engagement shoulder portion  117  extends horizontally, and is engaged by the horizontal leading ends of the free end portions of the locking spring members  77  when the insertion of the module  101  into the housing member  11  is completed ( FIG. 9 ). 
     A metallic coating is preferably formed on the side surfaces of the lower portion  111 , and the module  101  is electrically connected to the shell  71  by the free ends of the grounding spring members  78  contacting thereto when the insertion of the module  101  into the housing member  11  is completed. The contact members (not illustrated) are exposed to the bottom surface of the module  101 , and are connected to the contacting portions  64  of the corresponding terminals  61  when the insertion of the module  101  into the housing member  11  is completed. The module  101  is inserted into the housing member  11  with a predetermined orientation, by inserting the polarizing key  115  into the polarizing groove  37 , so that predetermined contact members exposed to the bottom surface of the module  101  are connected to predetermined terminals  61 . 
     When the module  101  is inserted into the housing member  11 , the side surfaces of the lower portion  111  of the module  101  move while contacting the free ends of the locking spring members  77  and the grounding spring members  78 . When the insertion of the module  101  into the housing member  11  is completed ( FIG. 9 ), the horizontal leading ends of the free end portions of the locking spring members  77  engage with the upper surface of the engagement shoulder portions  117  of the module  101 . The free end portions of the grounding spring members  78  are pressed by the side surface of the lower portion  111  of the module  101 . In this case, electrical contact between the free ends of the grounding spring members  78  and the metallic coating formed on the side surfaces of the lower portion  111  is secured by the grounding spring members  78 . 
     When the module is mounted, the body portions  66 , the arm connecting portions  69 , and the contact arm portions  68  of the terminals  61  are elastically deformed since the contacting portions  64  are pressed from above by the contact members exposed to the bottom surface of the module  101 , and take the shape as shown in  FIG. 9 . Therefore, electrical contact between the contacting portions  64  and the contact members of the module  101  is secured, by the spring function or nature of the body portions  66 , the arm connecting portions  69 , and the contact arm portions  68 . The module  101  receives the force to push it upward by the function of the terminal body portions  66 , the arm connecting portions  69 , and the contact arm portions  68  as a spring. However, the upward movement is restricted since the free ends of the locking spring members  77  engage with the upper surface of the engagement shoulder portions  117 . The module  101  is elastically held as being sandwiched vertically by the terminals  61  and the locking spring members  77 , so that the module  101  does not jump or bounce vertically. 
     The terminal  61  is divided into the right and left parts by the slit  67 , the first contact arm portions  68   a  are inclined more largely than the second contact arm portions  68   b , and the upper ends of the first contacting portions  64   a  are located higher than the upper ends of the second contacting portions  64   b.  If the dimensions of the modules  101  vary, at least any of the first contacting portions  64   a  or the second contacting portions  64   b  can reliably maintain contact with the contact members formed on the bottom surface. At least any of the first contacting portions  64   a  or the second contacting portions  64   b  applies a force to push the module  101  upward, the module  101  is elastically held or sandwiched vertically between the terminals  61  and the locking spring members  77  even if the dimensions of the module  101  vary. Each terminal  61  has a plurality of places for contacting the contact member of the module  101 , the contact of the terminal  61  with the contact member is reliably maintained even if the socket  1  receives impact from the outside. 
     The module  101  is elastically sandwiched from the opposite sides by the function of the locking spring members  77 , and also is sandwiched from four directions by the function of the grounding spring members  78  the module  101  does not jump or bounce horizontally. 
     Each terminal  61  has cantilever-like first and second contact arm portions  68   a  and  68   b , divided into right and left, or first and second contacting portions  64   a  and  64   b  formed on the free ends of the first and second contact arm portions  68   a  and  68   b  for contacting the contact member on the bottom of the module  101 , and the upper end of the first contacting portion  64   a  is positioned higher than the upper end of the second contacting portion  64   b  when the module  101  is not inserted. 
     Therefore, the contacting force of the terminals  61  is stabilized, and it is possible to reliably maintain the contact state between the terminal and the contact member of the module  101  even if the dimensions of the module  101  vary. 
     The position of the upper end of the first contacting portion  64   a  and the position of the upper end of the second contacting portion  64   b  are determined so as to correspond to the lower limit and the upper limit in the dimension error of the module  101 . The position of the bottom surface of the module  101  is at least in such a range that the first body portion  66   a , the first arm connecting portion  69   a , and the first contact arm portion  68   a  can generate a sufficient repulsion force, even if the distance between the upper surface and the bottom surface of the engagement shoulder portion  117  of the module  101  is in the range near the minimum value. Also, the position of the bottom surface of the module  101  is at least in such a range that the second body portion  66   b , the second arm connecting portion  69   b , and the second contact arm portion  68   b  can generate a sufficient repulsion force, even if the distance between the upper surface and the bottom surface of the engagement shoulder portion  117  of the module  101  is in the range near the maximum value. 
     The first contacting portion  64   a  and the second contacting portion  64   b  of each terminal  61  are provided for the same module contact member. Therefore, the terminal  61  has a plurality of places for contacting the contact member of the module  101 , and contact between the terminal  61  and the contact member can be reliably maintained even if the socket  1  receives impact from the outside due to any cause. 
     The module  101  is sandwiched and held from above and below by the locking spring members  77  engaging the upper surfaces of the engagement shoulder portions  117  and the first contacting portions  64   a  or the second contacting portions  64   b  contacting the contact members, when the module  101  is inserted. This makes it possible to reliably maintain the contact state between the terminal  61  and the contact member of the module  101  and it is possible to prevent slipping off of the module  101  since the function for locking the module  101  is strong. 
     The present invention is not limited to the above-described embodiments, and may be changed in various ways based on the gist of the present invention, and these changes are not eliminated from the scope of the present invention.