Abstract:
An IC socket includes a base portion having a support portion for supporting an IC device, and an external connection terminal for inputting a signal to the IC device and outputting a signal from the IC device; a lid portion having a pressing portion with a movable first projecting portion for pressing the IC device, and a fixing portion to be fixed to the base portion; and a first hinge for supporting the base portion and the lid portion to be movable.

Description:
BACKGROUND OF THE INVENTION AND RELATED ART STATEMENT  
       [0001]     The present invention relates to an IC socket and a test method of using the IC socket. Especially, the present invention relates to an IC socket for conducting an electrical characteristic test of an IC device such as a CSP (Chip Size Package) having an electrode in an area allay shape.  
         [0002]     Recently, it has been required to reduce a size and a weight of an electrical device such as a mobile electrical device. To this end, a CSP is mounted on and connected to a substrate with soldering as an IC device. Due to a small size of the IC device, it is difficult to directly input and output an electrical signal into and from the IC device itself, and it is necessary to provide a device called an IC socket for supporting the input and output of the electrical signal. Patent Reference 1 has disclosed such an IC socket.  
         [0000]     Patent Reference 1: Japanese Patent Publication No. 2001-013207  
         [0003]     In the IC socket disclosed in Patent Reference 1, when a lid is released from a pressurized state and an IC device is removed from the IC socket, the IC device tends to stick to a pressurized portion of the lid. This phenomenon may be caused by static charge generated during a test, moisture, or a sticky resin as well as a lightweight of the IC device. Especially when the IC device has a size less than 5 mm square, the phenomenon occurs more frequently. Once the IC device sticks to the IC socket, it is necessary to perform an additional step of taking out the IC device, thereby increasing a test time.  
         [0004]     In view of the problems described above, an object of the present invention is to provide an IC socket capable of preventing an IC device from sticking to a pressurized portion of the IC socket, thereby making it possible to reduce test time. Another object of the present invention is to provide a test method using the IC socket.  
         [0005]     Further objects and advantages of the invention will be apparent from the following description of the invention.  
       SUMMARY OF THE INVENTION  
       [0006]     In order to attain the objects described above, according to the present invention, an IC socket includes a base portion having a support portion for supporting an IC device, and an external connection terminal for inputting a signal to the IC device and outputting a signal from the IC device; a lid portion having a pressing portion with a movable first projecting portion for pressing the IC device, and a fixing portion to be fixed to the base portion; and a first hinge for supporting the base portion and the lid portion to be movable.  
         [0007]     According to the present invention, a test method includes a step of preparing an IC socket including a base portion having a support portion for supporting an IC device, and an external connection terminal for inputting a signal to the IC device and outputting a signal from the IC device; a lid portion having a pressing portion with a movable first projecting portion for pressing the IC device, and a fixing portion to be fixed to the base portion; and a first hinge for supporting the base portion and the lid portion to be movable; a step of mounting the IC device on the supporting portion; and a step of removing the IC device from the supporting portion.  
         [0008]     In the present invention, when the IC socket is used in an electrical property test, it is possible to prevent the IC device from sticking to the pressing portion of the IC socket, thereby eliminating tedious manual operations and reducing test time. 
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0009]      FIG. 1  is a perspective view showing an IC socket according to a first embodiment of the present invention;  
         [0010]      FIG. 2  is a sectional view of the IC socket according to the first embodiment of the present invention taken along line  2 - 2  in  FIG. 1 ;  
         [0011]      FIG. 3  is a sectional view showing an IC socket according to a second embodiment of the present invention;  
         [0012]      FIG. 4  is a sectional view of the IC socket according to the first embodiment of the present invention; and  
         [0013]      FIG. 5  is a sectional view showing a modified example of the IC socket according to the first embodiment of the present invention. 
     
    
     DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS  
       [0014]     Hereunder, embodiments of the present invention will be explained with reference to the accompanying drawings.  
         [0015]      FIG. 1  is a perspective view showing an IC socket according to a first embodiment of the present invention.  FIG. 2  is a sectional view of the IC socket according to the first embodiment of the present invention taken along line  2 - 2  in  FIG. 1 . First, the IC socket of the first embodiment will be explained with reference to  FIG. 1 .  
         [0016]     An IC socket  10  includes a base portion  11 ; a lid portion  12 ; and a first hinge  13 . A supporting portion  15  with a recessed shape is disposed at a center of the base portion  11  for mounting an IC device  14 . A pressing portion  16  with a protruding shape is disposed at the center of the lid portion  12  to face the supporting portion  15 . The pressing portion  16  has a space  17  inside thereof. First projecting portions  18  are disposed in the space  17 . The first projection portions  18  are formed such that the first projecting portions  18  extend and contract from a surface of the pressing portion  16  contacting with the IC device  14  when the IC device  14  is mounted. Adjusting portions  19  are disposed in the space  17  for adjusting the extension and contraction of the first projection portions  18 . The adjusting portions  19  and the first projection portions  18  are integrated together.  
         [0017]     Second projecting portions  20  are disposed on the supporting portion  15  to face the adjusting portions  19 . External connection terminals  21  are disposed in the supporting portion  15 , so that the external connection terminals  21  extend or can extend from a surface of the supporting portion  15  for mounting the IC device  14  thereon. The external connection terminals  21  are embedded in the base portion  11  from the supporting portion  15  and extend from the surface for mounting the IC device  14  to an opposite surface to be connected to a conductive pattern board. The lid portion  12  is provided with a fixing portion  22  on a side opposite to the first hinge  13  for fixing to the base portion  11 .  
         [0018]     An operation of the IC socket  10  will be explained next with reference to  FIG. 2  and  FIG. 4 .  FIG. 2  is a sectional view of the IC socket  10  in a state that the IC device  14  is mounted on the supporting portion  15  and the lid portion  12  of the IC socket  10  is closed. In the closed state of the lid portion  12 , the adjusting portions  19  are pushed upwardly with the second projecting portions  20 . Accordingly, the first projection portions  18  integrated with the adjusting portions  19  are retained in the pressing portion  16 .  
         [0019]     The second projecting portions  20  have a shape with a size reducing toward an upper side, so that the second projecting portions  20  are not caught when the lid portion  12  is opened. The second projecting portions  20  have a specific height to be determined through a design, so that the second projecting portions  20  and the adjusting portions  19  move smoothly. When the adjusting portions  19  have an enough length as shown in  FIG. 5 , it is possible to omit the second projecting portions  20 .  
         [0020]     A state that the IC socket  10  is opened will be explained next.  FIG. 4  shows the state that the IC socket  10  is opened from the state shown in  FIG. 2 . When the lid portion  12  is opened upwardly, the second projecting portions  20  no longer support the adjusting portions  19 , so that the adjusting portions  19  and the first projection portions  18  move downwardly in the space  17  with gravity. Accordingly, the first projection portions  18  retained in the pressing portion  16  protrude from the pressing portion  16 . Therefore, even if the IC device  14  sticks to the pressing portion  16  when the lid portion  12  is opened, it is possible to remove the IC device  14  with the first projection portions  18 .  
         [0021]     In the embodiment, the pressing portion  16  may be movably attached to the lid portion  12  through a second hinge, so that it is possible to prevent a local pressure from being applied to the IC device  14 . Further, the supporting portion  15  is movably attached to the base portion  11  through the external connection terminals  21 , so that it is possible to further prevent a local pressure from being applied to the IC device  14 . When a pressure is applied to the supporting portion  15  from the pressing portion  16 , the external connection terminals  21  are arranged to protrude from the surface of the supporting portion  15  mounting the IC device  14  thereon. Accordingly, it is possible to securely connect the IC device  14  to the external connection terminals  21 .  
         [0022]     The pressing portion  16  includes an upper pressing portion  24  and a lower pressing portion  25 . The space  17  is formed between the upper pressing portion  24  and the lower pressing portion  25  for retaining the first projection portions  18  and the adjusting portions  19 . When the upper pressing portion  24  and the lower pressing portion  25  are separately formed, it is easy to assemble the IC socket  10 .  
         [0023]     A test method using the IC socket  10  will be explained next. First, the IC socket  10  described above is prepared. Then, the IC device  14  is mounted on the supporting portion  15  of the IC socket  10 , and the lid portion  12  of the IC socket  10  is closed. A tester is connected to the IC socket  10  for conducting a test. After the test, the lid portion  12  of the IC socket  10  is opened to take out the IC device  14 .  
         [0024]     In the test method of the present invention, it is possible to prevent the IC device  14  from sticking to the pressing portion  16  when the lid portion  12  of the IC socket  10  is opened. Accordingly, it is possible to smoothly take out the IC device  14 .  
         [0025]      FIG. 3  is a sectional view showing an IC socket according to a second embodiment of the present invention. In the second embodiment, only differences from the first embodiment will be explained.  
         [0026]     An IC socket  30  includes first projecting portions  38 ; adjusting portions  39 ; and elastic members  46  disposed between the projecting portions  38  and an inner surface of a pressing portion  36 . The elastic members  46  are formed of a spring or a resin. The elastic members  46  are disposed at an upper side or a lower side of the first projecting portions  38  and the adjusting portions  39 , or both of the upper side and lower side of the first projecting portions  38  and the adjusting portions  39 . It is possible to adjust a force of the elastic members  46  applied to the first projecting portions  38  and the adjusting portions  39  through adjusting spring modulus and extension.  
         [0027]     When the spring modulus and extension are adjusted so that the force of the elastic members  46  is applied downwardly upon opening the lid portion, even if the first projecting portions  38  and the adjusting portions  39  have lightweight due to a material, it is still possible to smoothly remove an IC device  34 . On the other hand, when the spring modulus and extension are adjusted so that the force of the elastic members  46  is applied upwardly upon opening the lid portion, even if the first projecting portions  38  and the adjusting portions  39  are made of metal, it is possible to absorb an impact on the IC device  34  when the IC device  34  is removed.  
         [0028]     The disclosure of Japanese Patent Application No. 2004-358707, filed on Dec. 10, 2004, is incorporated in the application.  
         [0029]     While the invention has been explained with reference to the specific embodiments of the invention, the explanation is illustrative and the invention is limited only by the appended claims.