Abstract:
Provided is a test socket capable of being used more flexibly for solid-state image pickup devices of different shapes and of performing locating of the solid-state image pickup devices more precisely. The test socket houses a tested device which is a solid-state image pickup device while a test is being performed. The test socket comprises: first locating means for locating the tested device in an X direction parallel to a ceiling plane of the tested device in a housed state; urging means for urging the first locating means in a Z direction perpendicular to the ceiling plane of the tested device in the housed state; and position setting means for setting an upper limit of movement in the Z direction of the first locating means caused by the urging means to set a position in the Z direction of the first locating means relative to the tested device.

Description:
CROSS REFERENCE TO RELATED APPLICATION 
       [0001]    This Nonprovlsional application claims priority under 35 U.S.C. §119(a) on Patent Application No. 2007-238827 filed in Japan on Sep. 14, 2007, the entire contents of which are hereby incorporated by reference. 
       BACKGROUND OF THE INVENTION 
       [0002]    1. Field of the Invention 
         [0003]    The present invention relates to a test socket including locating means for locating a solid-state image pickup device fitted therein. 
         [0004]    The present invention relates to a socket configured to locate a solid-state image pickup device inserted therein so as to enable optical centering at all times, and hence being adaptable to solid-state image pickup devices of different sizes. 
         [0005]    2. Description of the Related Art 
         [0006]    Recently, with the remarkable advancement in performance of image pickup instruments using solid-state image pickup devices, such as cellular phones with a camera function and digital still cameras, the solid-state image pickup devices have also become increasingly advanced in performance, e.g., having a mega number of pixels and a wide angle of view. In addition, some solid-state image pickup devices are densely packed by mounting a circuit board, such as a flexible printed board or a rigid board, implementing a camera driving circuit thereon. 
         [0007]    In a manufacturing process of solid-state image pickup devices, various tests are conventionally performed to screen out defective products. The test of a solid-state image pickup device is usually performed with the solid-state image pickup device of the test target being fitted in a test socket provided in a tester for electrical testing, characteristic evaluation, or the like. 
         [0008]    The structure of a test socket for a solid-state image pickup device is briefly described below with reference to  FIG. 7 .  FIG. 7  illustrates an exemplary schematic configuration of a conventional test socket for a solid-state image pickup device, in particular, of a test socket  100  for a solid-state image pickup device mounted with a circuit board. 
         [0009]    As shown in  FIG. 7 , the test socket  100  includes a base  110  and a cover  120  to house a solid-state image pickup device. The base  110  is provided with a first recess  111  that conforms to the lower shape of the main body including the circuit board of the solid-state image pickup device. The cover  120  is provided, at a position corresponding to the position of the first recess  111 , with a second recess  121  that conforms to the upper shape of the main body including the circuit board of the solid-state image pickup device. The first recess  111  provided in the base  110  and the second recess  121  provided in the cover  120  jointly house the solid-state image pickup device. A contact portion including a plurality of contact pins is provided on the bottom surface of the first recess  111  in the base  110  so as to establish electrical connection with terminals of the solid-state image pickup device. It should be noted that the first recess  111  in the base  110  and the second recess  121  in the cover  120  are usually provided with some play to allow the solid-state image pickup device to be smoothly fitted/released. 
         [0010]    In order to perform a test in a favorable manner for a solid-state image pickup device, especially for a high-performance solid-state image pickup device as mentioned above, the focal point and angle of view of the solid-state image pickup device should be adjusted to an optical center as accurately as possible. As described above, however, since the first recess  111  in the base  110  and the second recess  121  in the cover  120  of the test socket  100  are usually provided with some play, the solid-state image pickup device should be located as precisely as possible in order to perform the test with a satisfactory degree of accuracy. 
         [0011]    Exemplary techniques for locating a solid-state image pickup device in a test socket include one using a test socket having, as locating means for locating and fixing the solid-state image pickup device in a direction (a first direction) parallel to the ceiling plane of the solid-state image pickup device in a housed state, movable chucks to urge toward the center each of predetermined two diagonal corners out of the corners of the solid-state image pickup device (see, e.g., Japanese Unexamined Patent Publication No. 2007-109534). 
         [0012]    In a case, however, where, e.g., a test is performed using a conventional test socket on a solid-state image pickup device mounted with a circuit board, and the circuit board is mounted at such a position that locating means of the test socket contacts the solid-state image pickup device, it is sometimes difficult to locate the solid-state image pickup device in fitting the solid-state image pickup device into the test socket, because of, e.g., the contact between the locating means and the circuit board. In such a case, there arises a need to fabricate a test socket dedicated for each of the shapes of solid-state image pickup devices so as to accommodate different shapes of the solid-state image pickup devices. 
       SUMMARY OF THE INVENTION 
       [0013]    The present invention was made in view of the foregoing problems, and it is an object of the present invention to provide a test socket capable of being used more flexibly for solid-state image pickup devices of different shapes and of performing locating of the solid-state image pickup devices more precisely. 
         [0014]    According to a first feature, a test socket according to the present invention for achieving the above object relates to a test socket for housing a tested device while a test is being performed, the tested device being a solid-state image pickup device, the test socket comprising: first locating means for locating the tested device in a first direction parallel to a ceiling plane of the tested device in the housed state; urging means for urging the first locating means in a second direction perpendicular to the ceiling plane of the tested device in the housed state; and position setting means for setting an upper limit of the movement in the second direction of the first locating means caused by the urging means to set a position in the second direction of the first locating means relative to the tested device. 
         [0015]    According to a second feature, in the test socket according to the above feature of the present invention, the first locating means may comprise: a first fixing portion that is disposed on the test socket fixedly with respect to the first direction and supports a first corner which is one of corners on a diagonal of the tested device; and a second fixing portion that is provided in a slidable manner in a direction parallel to the diagonal of the tested device and urges, toward the first fixing portion, a second corner which is the other of the corners on the diagonal of the tested device. 
         [0016]    According to a third feature, in the test socket according to any of the above features of the present invention, the urging means and a contact portion including a plurality of contact terminals to establish electrical connection with terminals of the tested device may be provided at a side opposite in direction to the second direction with respect to the first locating means, and the test socket may further comprise second locating means for urging the tested device in a direction opposite to the second direction from a side along the second direction with respect to the first locating means to fix a position of the ceiling plane of the tested device to a predetermined ceiling position. 
         [0017]    According to a fourth feature, in the test socket according to the above feature of the present invention, the contact terminals may be arranged in a matrix in the contact portion. 
         [0018]    Since the test socket according to the above-described features includes the urging means for urging the first locating means in the second direction and the position setting means for setting the upper limit of the movement in the second direction of the first locating means caused by the urging means, it becomes possible to control the position in the second direction of the first locating means as appropriate relative to the solid-state image pickup device in the housed state. With this structure, in the case of, e.g., performing a test on a solid-state image pickup device mounted with a circuit board, the test socket according to the above-described features can set the position where the first locating means contacts the solid-state image pickup device to a position outside the circuit board mounting portion. Accordingly, the test socket according to the above-described features can be used for solid-state image pickup devices of different shapes more flexibly, hence allowing a solid-state image pickup device to be housed and fixed therein regardless of present or absence of a built-in circuit board. 
         [0019]    Also, since the test socket according to the above-described features includes the first locating means for locating the solid-state image pickup device in the direction (the first direction) parallel to the ceiling plane of the solid-state image pickup device in the housed state, the locating in the first direction can be performed accurately. With this structure, the focal point and angle of view of a solid-state image pickup device can be adjusted more accurately to an optical center. 
         [0020]    In the test socket according to the second feature, the first locating means may include the first fixing portion that supports and fixes the first corner of the solid-state image pickup device and the second fixing portion that urges the second corner of the solid-state image pickup device toward the first corner, the second corner being diagonally across the first corner; therefore, the first locating means can be provided in a simple structure, and the locating in the first direction can be carried out accurately. 
         [0021]    The test socket according to the third feature may include the second locating means for urging the tested device from the side along the second direction of the first locating means in the direction opposite to the second direction, so as to fix the position of the ceiling plane of the tested device to a predetermined ceiling position; therefore, the locating in the second direction can be performed accurately. 
         [0022]    The test socket according to the fourth feature may include the contact portion in which the contact terminals are arranged in a matrix; therefore, the same test socket can be used for the solid-state image pickup devices that have the same side-to-terminal distance and the same terminal interval. Accordingly, it becomes possible to cut costs involved in the test and reduce the time required for developing test sockets. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0023]      FIG. 1  is a top view showing an exemplary schematic configuration of an opened test socket according to the present invention; 
           [0024]      FIGS. 2A and 2B  are schematic views showing exemplary configurations of main portions of a base of the test socket according to the present invention; 
           [0025]      FIG. 3  is a top view showing an exemplary schematic configuration of the base of the test socket according to the present invention with a tested device fixed therein; 
           [0026]      FIG. 4  is a top view showing an exemplary schematic configuration of the base of the test socket according to the present invention, where the tested device can be fitted or released; 
           [0027]      FIG. 5  is a top view showing an exemplary schematic configuration of a contact portion of the test socket according to the present invention; 
           [0028]      FIG. 6  is an end view showing a configuration of a latch member for interlocking a cover with the base; and 
           [0029]      FIG. 7  is a perspective view showing the schematic configuration of a conventional test socket for a solid-state image pickup device. 
       
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENTS 
       [0030]    Embodiments of a test socket according to the present invention are described below with reference to the drawings. 
         [0031]    A structure of a test socket according to the present invention is described with reference to  FIGS. 1 to 6 .  FIG. 1  shows an exemplary schematic configuration of an opened test socket  1  according to the present invention.  FIGS. 2A and 2B  show exemplary schematic configurations of main portions of a base  10  to be described later of the test socket  1  shown in  FIG. 1 , where  FIG. 2A  is a cross-sectional view taken along line A-A′ in  FIG. 2B , and  FIG. 2B  is a top view of the base  10 . It should be noted that the present embodiment is described on the assumption that the tested device to be housed in the test socket is a solid-state image pickup device that includes a circuit board in a lower portion of its main body and an image pickup portion on its ceiling plane. 
         [0032]    As shown in  FIG. 1 , the test socket  1  includes the base  10  and a cover  20  that have an approximately rectangular solid shape. As in the conventional technique, the base  10  is provided with a first recess  11  that conforms to the lower shape of the main body including the circuit board of the tested device, whereas the cover  20  is provided, at a position corresponding to the first recess  11 , with a second recess  21  that conforms to the upper shape of the main body including the circuit board of the tested device. The first recess  11  provided in the base  10  and the second recess  21  provided in the cover  20  jointly house the tested device. It should be noted that, as in the conventional technique, the first recess  11  in the base  10  and the second recess  21  in the cover  20  are provided with some play so as to allow the tested device to be smoothly fitted/released. Moreover, the test socket  1  includes a latch member  19  for interlocking the cover  20  with the base  10 . 
         [0033]    As shown in  FIGS. 1 ,  2 A, and  2 B, the base  10  includes first locating means  12 , urging means  13 , and position setting means  14 . The first locating means  12  locates the tested device in an X direction (corresponding to the first direction) parallel to the ceiling plane of the tested device in a housed state. The urging means  13  urges the first locating means  12  in a Z direction (corresponding to the second direction) perpendicular to the ceiling plane of the tested device in the housed state. The position setting means  14  sets an upper limit of the movement in the Z direction of the first locating means  12  caused by the urging means  13  and sets the position in the Z direction of the first locating means  12  relative to the tested device. It should be noted that the present embodiment is described on the assumption that the urging means  13  uses springs  13 , and that the position setting means  14  uses screws  14 . 
         [0034]    More specifically, as shown in  FIGS. 2A and 2B , the first locating means  12  of the base  10  includes first and second fixing portions  12   a  and  12   b . The first fixing portion  12   a  is disposed on the test socket  1  fixedly with respect to the X direction and supports a first corner which is one of the corners on a diagonal of the tested device in a housed state. The second fixing portion  12   b  is provided in a slidable manner in a direction parallel to the diagonal AA′ (the X direction in the present embodiment) and urges a second corner which is the other of the corners on the diagonal toward the first fixing portion  12   a.    
         [0035]    As shown in  FIGS. 2A and 2B , the first fixing portion  12   a  is constructed using an approximately L-shaped plate-like member with an approximately right-angled triangular cutout that fits the first corner of the tested device. The plate-like member includes a pair of openings that individually passes a pair of supports  15  in a slidable manner in the Z direction. The paired supports  15  are disposed in the respective openings in the plate-like member, so that the position of the first fixing portion  12   a  can be fixed in the X direction, and that the urging means  13  and the position setting means  14 , as well as second locating means, can be moved in the Z direction, which will be described later. 
         [0036]    As shown in  FIGS. 2A and 2B , the plate-like member of the first fixing portion  12   a  includes an opening to pass a screw  14   a  serving as the position setting means  14  in a slidable manner in the Z direction. The screw  14   a  is passed through the opening in the plate-like member of the first fixing portion  12   a , past a spring  13   a  serving as the urging means  13 , and is partly fastened to the base  10 . The plate-like member of the first fixing portion  12   a  is urged in the Z direction by the spring  13   a  disposed between the plate-like member of the first fixing portion  12   a  and the base (i.e., fitted at the side opposite in direction to the Z direction of the first locating means  12 ). While the test socket  1  is opened, the plate-like member of the first fixing portion  12   a  is fixed in contact with a thread of the screw  14   a . That is, the fastening tightness of the screw  14   a  determines an upper limit of movement in the Z direction of the plate-like member of the first fixing portion  12   a . The screw  14   a  may be fastened tightly to the base  10  to set the upper limit of the movement at a low position, whereas the screw  14   a  may be fastened loosely to the base  10  to set to upper limit of the movement at a high position. 
         [0037]    As shown in  FIGS. 2A and 2B , the second fixing portion  12   b  includes a plate-like member with an approximately right-angled triangular cutout  12   c  that fits the second corner of the tested device, as well as a spring  12   d  to urge the plate-like member in the X direction. The plate-like member includes an opening  17  to pass a support  16  therethrough. The opening  17  is approximately formed into a track so as to permit the plate-like member of the second fixing portion  12   b  to slide in the X and Z directions by disposing the support  16  in the opening  17 . 
         [0038]      FIG. 3  shows a positional relationship between the second fixing portion  12   b  and the base  10  while the tested device can be fitted/released, whereas  FIG. 4  shows a positional relationship between the second fixing portion  12   b  and the base  10  while the tested device is fixed. To fit the tested device in the test socket  1 , the second fixing portion  12   b  is first moved in the X direction to bring the test socket  1  into the receivable state shown in  FIG. 3 , and the lower portion of the tested device is inserted into the first recess  11  of the base  10 . The spring  12   d  urges the second fixing portion  12   b  in a direction opposite to the X direction, whereby the tested device is located in the X direction with its first and second corners held by the first and second fixing portions  12   a  and  12   b . The tested device can be located accurately with its first corner being fixed at the same position, i.e., meeting the cutout of the first fixing portion  12   a , at all times. 
         [0039]    Further, as shown in  FIGS. 2A and 2B , the plate-like member of the second fixing portion  12   b  includes a pair of openings to pass a pair of screws  14   b  serving as the position setting means  14  in a slidable manner in the Z direction. The screws  14   b  are passed through the respective openings in the plate-like member of the second fixing portion  12   b , past springs  13   b  serving as the urging means  13 , and are partly fastened to the base  10 . The plate-like member of the second fixing portion  12   b  is urged in the Z direction by the springs  13   b  disposed between the plate-like member of the second fixing portion  12   b  and the base. While the test socket  1  is opened, the plate-like member of the second fixing portion  12   b  is fixed in contact with threads of the screws  14   b . That is, the fastening tightness of the screws  14   b  determines an upper limit of the movement in the Z direction of the plate-like member of the second fixing portion  12   b . The screws  14   b  may be fastened tightly to the base  10  to set the upper limit of the movement at a low position, whilst the screws  14   b  may be fastened loosely to the base  10  to set the upper limit of the movement at a high position. 
         [0040]    It should be noted that the screw  14   a  for setting the upper limit of the movement in the Z direction of the first fixing portion  12   a  and the screws  14   b  for setting the upper limit of the movement in the Z direction of the second fixing portion  12   b  are desirably fastened to the base  10  such that the plate-like member of the first fixing portion  12   a  and the plate-like member of the second fixing portion  12   b  are set at an equal level; however, the present invention is not limited thereto, and the setting is performed appropriately in view of the thicknesses of the plate-like members, the mounting position of the circuit board in the tested device, and the like. Accordingly, the tested device can be fixed with the first and second fixing portions  12   a  and  12   b  being kept from contacting the circuit board and the like of the tested device. 
         [0041]    The base  10  is provided at its bottom with a contact portion  18  including a plurality of contact terminals  18   a  (contact pins  18   a ) so as to establish electrical connection with terminals of the tested device. In the present embodiment, the contact terminals  18   a  are arranged in a matrix in the contact portion  18 . 
         [0042]      FIG. 5  shows an exemplary schematic configuration of the contact portion  18 . As described above, the second fixing portion  12   b  is constructed to be slidable in the X direction in  FIGS. 2A ,  2 B, and  5 . Accordingly, the present invention is adaptable to, as shown in  FIG. 5 , solid-state image pickup devices that have the same end-to-terminal distance and the same terminal interval in tested devices thereof, and that are equal to or below the maximum size of the solid-state image pickup devices, which size is dependent on the number and arrangement of the contact terminals  18   a  of the contact portion  18 . 
         [0043]    The cover  20  to serve as the second locating means renders the test socket, with the tested device placed in the first recess  11  of the base  10 , closed by interlocking with the base  10  through the latch member  19  to be described later, thereby urging the tested device in a direction opposite to the Z direction to fix the position of the ceiling plane of the tested device to a predetermined ceiling position. More specifically, in the present embodiment, the second recess  21  in the cover  20  is provided so as to contact the ceiling plane of the tested device, which allows the position in the Z direction of the image pickup portion provided on the ceiling plane of the tested device to be fixed at the same position relative to the cover  20  at all times. 
         [0044]    Moreover, the cover  20  of the present invention includes a third recess  21   a  to ensure the movement of the second fixing portion  12   b . The third recess  21   a  has a shape that conforms to the shape of the second fixing portion  12   b.    
         [0045]    As shown in  FIG. 6 , the latch member  19  includes an interlocking portion  19   a , a spring  19   b , and a releasing portion  19   c . The interlocking portion  19   a  of the latch member  19  is urged by the spring  19   b  toward the cover  20  to automatically interlock with an interlocking portion  22  of the cover  20  when the test socket  1  is closed. When the releasing portion  19   c  of the latch member  19  is pressed oppositely to the Z direction while the latch member  19  is interlocked, the cover  20  is released from the interlocking state. It should be noted that, in the present embodiment, as shown in  FIG. 1 , the base  10  and the cover  20  of the test socket  1  are urged in an opening direction, and thus the test socket will automatically be opened as shown in  FIG. 1  upon release of the interlocking via the latch member  19 . 
       Other Embodiments 
       [0046]    (1) The foregoing embodiment is described of a case in which the base  10  includes the first locating means  12 , the urging means  13 , and the position setting means  14 ; however, the present invention is not limited thereto, and the cover  20  may include all or part of these components. 
         [0047]    (2) Although the foregoing embodiment is described on the assumption that the urging means  13  uses the springs  13  and the position setting means  14  uses the screws  14 , the present invention is not limited thereto. The urging means  13  may be, e.g., an elastic member other than springs, a motor, or the like, and the position setting means  14  is constructed in accordance with the structure of the urging means  13 . 
         [0048]    (3) Although the foregoing embodiment is described based on an example where the tested device is a solid-state image pickup device mounted with a circuit board, the present invention is not limited thereto. The test socket according to the present invention is particularly useful for tested devices that are limited in area to be contacted by the first locating means  12 . It should be noted that in a case of a solid-state image pickup device without a circuit board and the like, the position in the Z direction of the first locating means  12  can be selected so as to favorably fix the solid-state image pickup device in view of the structure of the device. 
         [0049]    Although the present invention has been described in terms of the preferred embodiment, it will be appreciated that various modifications and alternations might be made by those skilled in the art without departing from the spirit and scope of the invention. The invention should therefore be measured in terms of the claims which follow.