Abstract:
A socket pin for electrically connecting a semiconductor substrate to a test substrate, comprising: a pin head; a pin body configured to support the pin head; and a length adjusting part provided below the pin body; wherein: the length adjusting part comprises at least a portion protruding from the pin body and a resilient structure; and the length adjusting part is movable to change a length of the portion protruding from the pin body as the resilient structure distorts.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
       [0001]    This U.S. non-provisional patent application claims priority under 35 U.S.C. §119 to Korean Patent Application No. 10-2015-0172569, filed on Dec. 4, 2015, in the Korean Intellectual Property Office, the entire contents of which are hereby incorporated by reference. 
       BACKGROUND 
       [0002]    Embodiments relate to a socket pin and a semiconductor package test system including the same. 
         [0003]    Various test steps are performed to examine whether there is a failure in a fabricated semiconductor package. By performing the test steps, it is possible to maintain reliability of the semiconductor package. In particular, a burn-in test, one of the test steps, is performed at an initial stage of the test process. To perform the burn-in test, a semiconductor package is mounted on a test socket, and the test socket with the semiconductor package is loaded on a test substrate. 
       SUMMARY 
       [0004]    Some embodiments include a socket pin for electrically connecting a semiconductor substrate to a test substrate, comprising: a pin head, a pin body configured to support the pin head and a length adjusting part provided below the pin body, wherein the length adjusting part comprises at least a portion protruding from the pin body and the length adjusting part is movable to change a length of the portion protruding from the pin body. 
         [0005]    Some embodiments include a semiconductor package test system, comprising: a test substrate having a top surface, on which a recess region is formed; and a test socket provided on the test substrate and configured to receive a semiconductor package; wherein the test socket comprises: a base comprising a first through hole; and a socket pin inserted in the first through hole to electrically connect the recess region of the test substrate to the semiconductor package, wherein the socket pin comprises a length adjusting part that is movable to adjust a length of the socket pin based on a height of the recess region of the test substrate. 
         [0006]    Some embodiments include A socket pin for electrically connecting a semiconductor substrate to a test substrate, comprising: a pin head; a pin body configured to support the pin head; a length adjusting part provided below the pin body; and a supporting part connected to the pin body; wherein: the length adjusting part comprises at least a portion extending through the pin body; and the length adjusting part is movable within the supporting part to change a length of the socket pin. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0007]    Embodiments will be more clearly understood from the following brief description taken in conjunction with the accompanying drawings. The accompanying drawings represent non-limiting, example embodiments as described herein. 
           [0008]      FIG. 1A  is a sectional view illustrating a semiconductor package test system. 
           [0009]      FIG. 1B  is an enlarged view illustrating a portion ‘A’ of  FIG. 1A . 
           [0010]      FIG. 2  is a diagram illustrating a socket pin of  FIGS. 1A and 1B . 
           [0011]      FIG. 3A  is a perspective view illustrating a semiconductor package test system according to some embodiments. 
           [0012]      FIG. 3B  is a perspective sectional view taken along line I-I′ of  FIG. 3A . 
           [0013]      FIG. 3C  is an enlarged view illustrating a portion ‘B’ of  FIG. 3B . 
           [0014]      FIG. 4A  is a perspective view illustrating a socket pin of  FIGS. 3A to 3C . 
           [0015]      FIG. 4B  is a sectional view illustrating a pin head of  FIG. 4A  connected to a first terminal, and  FIG. 4C  is an enlarged view of a length adjusting part of  FIG. 4A . 
           [0016]      FIGS. 5A and 5B  are diagrams schematically illustrating a reduction in length of a socket pin, which occurs when the socket pin is in contact with a test substrate. 
           [0017]      FIGS. 6A and 6B  are diagrams schematically illustrating restoration of the socket pin to an initial length, which occurs when the socket pin is separated from the test substrate. 
           [0018]      FIG. 7A  is a perspective view illustrating a socket pin according to some embodiments. 
           [0019]      FIGS. 7B and 7C  are diagrams schematically illustrating a process of changing a length of the socket pin of  FIG. 7A . 
           [0020]      FIG. 8A  is a perspective view illustrating a socket pin according to some embodiments. 
           [0021]      FIGS. 8B and 8C  are diagrams schematically illustrating a process of changing a length of the socket pin of  FIG. 8A . 
       
    
    
     DETAILED DESCRIPTION 
       [0022]    Embodiments will now be described more fully hereinafter with reference to the accompanying drawings, in which particular embodiments are shown. 
         [0023]      FIG. 1A  is a sectional view illustrating a semiconductor package test system, and  FIG. 1B  is an enlarged view illustrating a portion ‘A’ of  FIG. 1A . In  FIG. 1B , a portion of the semiconductor package test system is exaggerated or omitted to clearly show a connection structure of a socket pin  15 .  FIG. 2  is a diagram illustrating a socket pin  15  of  FIGS. 1A and 1B . A semiconductor package test system  10  may include a test socket  12  and a test substrate  18 . The test socket  12  may be provided on the test substrate  18  to test electric performance of a semiconductor substrate P (e.g., see  FIG. 3 ). 
         [0024]    Referring to  FIGS. 1A, 1B, and 2 , the test socket  12  may include a base  110 , a slider  120 , a cover  130 , an adaptor  140 , a socket pin  15 , a stopper  160 , and a lead guide  170 . The base  110  may be provided on the test substrate  18  to define a space  135  containing the semiconductor substrate P. The base  110  may have first through holes  112 , and the socket pins  15  may be inserted into the first through holes  112 . The slider  120  may be coupled to the base  110  and may have second through holes  122 , and the socket pins  15  may be inserted into the second through holes  122 . The slider  120  may be configured to align the socket pin  15 . As an example, the socket pin  15  (e.g., see  FIG. 2 ) may include a pin head  15   a  protruding upward from the second through holes  122 , and a position of the slider  120  may be changed to align the socket pin  15 . For example, through holes  112 ,  122 ,  162 ,  172 ,  18   a  may be provided to have widths greater than that of the socket pin  15 . By moving the slider  120 , the socket pin  15  may be changed to be aligned. The cover  130  may be coupled to a top portion of the base  110 . The adaptor  140  may be provided in the cover  130  and may be used to guide and contain the semiconductor substrate P in the space  135 . The adaptor  140  may be shaped like a rectangular ring and may have inclined surfaces. The adaptor  140  may be configured to guide the semiconductor substrate P to the space  135 . 
         [0025]    The socket pin  15  may be configured to connect the semiconductor substrate P electrically with the test substrate  18 . The socket pin  15  may include opposite end portions, which are connected to the test substrate  18  and the semiconductor substrate P, respectively. For example, the pin head  15   a  of the socket pin  15  may be connected to the semiconductor substrate P, and a pin tail  15   c  of the socket pin  15  may be connected to the test substrate  18 . 
         [0026]    Referring to  FIG. 2 , the socket pin  15  may include a pin head  15   a , a pin body  15   b , and a pin tail  15   c . The pin head  15   a , which is an upper portion of the socket pin  15 , may be electrically connectable to the semiconductor substrate P. The pin head  15   a  may have two opposite bodies. For example, the pin head  15   a  may be provided in the form of a letter ‘Y’. In other examples, the pin head  15   a  may be provided in the form of a single body or in any other shape. The pin tail  15   c , which is a lower portion of the socket pin  15 , may be electrically connected to the test substrate  18 . The pin body  15   b  may be configured to connect the pin head  15   a  to the pin tail  15   c . The socket pin  15  may be provided to sequentially pass through the slider  120 , the base  110 , the stopper  160 , the lead guide  170 , and the test substrate  18  of  FIG. 1A . 
         [0027]    Referring back to  FIGS. 1A and 1B , the stopper  160  may be provided in the base  110 . The stopper  160  may be configured to have third through holes  162 . The socket pins  15  may be inserted into the third through holes  162 , and thus, the socket pins  15  may be fastened by the stopper  160 . The lead guide  170  may be provided in the base  110 . For example, the lead guide  170  may be provided below the stopper  160 . The lead guide  170  may be configured to have fourth through holes  172 . The socket pins  15  may be inserted into the fourth through holes  172 . The lead guide  170  may be configured to protect the socket pin  15 . 
         [0028]    The test substrate  18  may be provided to have fifth through holes  18   a . The socket pins  15  may be inserted into the fifth through holes  18   a . The test substrate  18  may be, for example, a printed circuit board (PCB). The pin tail  15   c  may be provided to pass through the fifth through hole  18   a  and may have an end portion exposed by the test substrate  18 . A soldering element  18   b  may be formed on the exposed end portion of the pin tail  15   c , and thus, the socket pin  15  may be fastened to the test substrate  18 . 
         [0029]    According to the above configuration of the semiconductor package test system, the fifth through holes  18   a  of the test substrate  18  should be formed in accordance with a type of the semiconductor substrate P and a ball pitch. In addition, since the socket pin  15  is fastened to the test substrate  18  by the soldering element  18   b , both of the socket pin  15  and the test substrate  18  may be discarded when the test process is finished. 
         [0030]      FIG. 3A  is a perspective view illustrating a semiconductor package test system according to some embodiments, and  FIG. 3B  is a perspective sectional view taken along line I-I′ of  FIG. 3A .  FIG. 3C  is an enlarged view illustrating a portion ‘B’ of  FIG. 3B . In  FIG. 3C , a portion of the semiconductor package test system is exaggerated or omitted to clearly show a connection structure of a socket pin  150 . In the following description, an element previously described with reference to  FIGS. 1A and 1B  may be identified by a similar or identical reference number without repeating an overlapping description thereof. Although the description that follows will refer to an example in which a test socket  105  and a semiconductor package test system  100  are used to perform a burn-in test, other embodiments are not limited to the burn-in test. In addition, the description that follows will refer to a ball grid array (BGA)-type semiconductor package with solder balls, but other embodiments may be applicable to other types of semiconductor packages (e.g., TSOP or LGA). 
         [0031]    A semiconductor package test system  100  may include a test socket  105  and a test substrate  180 . The test socket  105  may be provided on the test substrate  180  and may be used to test electric performance of the semiconductor substrate P. The semiconductor substrate P may be a packaged substrate, a packaged semiconductor device or system, or the like. The semiconductor substrate P may include first terminals (e.g., see P 1  of  FIG. 4B ) provided on a bottom surface thereof, and the test substrate  180  may include second terminals  182 . Each of the first terminals P 1  may be shaped like a ball, and each of the second terminals  182  may be shaped like a pad; however, in other embodiments, the first terminals P 1  and the second terminals  182  may have other forms. 
         [0032]    The test socket  105  may include a base  110 , a slider  120 , a cover  130 , a ball guide plate  145 , a socket pin  150 , a stopper  160 , and a lead guide  170 . The base  110  may be provided on the test substrate  18  to define a space  135  to contain the semiconductor substrate P. The base  110  may be provided to have first through holes  112 , and the socket pins  150  may be inserted into the first through holes  112 . The slider  120  may be coupled to the base  110  and may have second through holes  122 , and the socket pins  150  may be inserted into the second through holes  122 . The slider  120  may be configured to align the socket pin  150 . The cover  130  may be coupled to a top portion of the base  110 . The cover  130  may have a hollow structure. The cover  130  may be connected to the base  110  and may be used to operate the slider  120 . The ball guide plate  145  may be provided on the slider  120 . The ball guide plate  145  may include ball guide holes  147 , in which the first terminals P 1  of the semiconductor substrate P may be provided. Since the first terminals P 1  may be provided in the ball guide holes  147 , the semiconductor substrate P may be stably disposed in the space  135 . Since the ball guide holes  147  need not be limited by a size of the semiconductor substrate P, various sizes of the semiconductor substrate P can be loaded on the ball guide holes  147 . 
         [0033]      FIG. 4A  is a perspective view illustrating the socket pin  150  of  FIGS. 3A to 3C .  FIG. 4B  is a sectional view illustrating a pin head  150   a  of  FIG. 4A  connected to the first terminal P 1 , and  FIG. 4C  is an enlarged view of a length adjusting part  152  of  FIG. 4A . Referring to  FIGS. 4A to 4C , the socket pin  150  may include a pin head  150   a , a pin body  150   b , a length adjusting part  152 , and a supporting part  158 . The pin head  150   a  may be an upper portion of the socket pin  150  and may be electrically connectable to the semiconductor substrate P. As an example, the pin head  150   a  may be configured to be placed in contact with the first terminal P 1  of the semiconductor substrate P. The pin head  150   a  may have two opposite bodies. For example, the pin head  150   a  may be provided in the form of a letter ‘Y’, and the first terminal P 1  may be inserted into a region between the two bodies. However, other embodiments are not limited thereto, and the pin head  150   a  may be provided in the form of a single body or in any other shape. The pin head  150   a  may include a head part  150   aa  and pin head supporting parts  150   ab . The head part  150   aa  may be configured to contact a side surface of the first terminal P 1 . In other words, the socket pin  150  may be of a pinch type that, when moved to surround the first terminal P 1 , may be compressed or otherwise deformed to contact the first terminal P 1 . The pin head supporting parts  150   ab  may be overlapped with the pin body  150   b . The pin head supporting parts  150   ab  may be coupled to the pin body  150   b  to support the head part  150   aa . For example, the pin head supporting parts  150   ab  may have a structure extending in a height direction. The pin body  150   b  may be configured to support the pin head  150   a.    
         [0034]    The length adjusting part  152  may be provided below the pin body  150   b . The length adjusting part  152  may be a lower portion of the socket pin  150  and may be electrically connectable to the test substrate  180  (e.g., second terminals  182 ). Furthermore, the supporting part  158  may be configured to be a part of the pin body  150   b . The length adjusting part  152  may include at least a portion protruding outwardly from the pin body  150   b  and may be configured in such a way that a length thereof from the bottom surface of the pin body  150   b  can be changed. Accordingly, a total length of the socket pin  150  can be changed. The length adjusting part  152  may include a first portion  154  and a second portion  156 . For example, the first portion  154  may be a lower portion of the length adjusting part  152 , and the second portion  156  may be an upper portion of the length adjusting part  152 . The first portion  154  may include at least a portion protruding outwardly from the bottom surface of the pin body  150   b . The second portion  156  may be connected to the first portion  154  and may be inserted into the pin body  150   b . For example, the second portion  156  may extend from the first portion  154 . The second portion  156  may be provided in the form of a hook. If a pressure is applied to the socket pin  150  in its length direction, the hook-shaped portion of the second portion  156  may be inserted into the pin head supporting parts  150   ab . The second portion  156  may be a rigid body (e.g., metal or metal alloy). Accordingly, if the second portion  156  is inserted into the pin head supporting parts  150   ab , a resistant force pushing the second portion  156  in a direction out of the pin head supporting parts  150   ab  may be applied to the second portion  156  and hence, the length adjusting part  152 . 
         [0035]    The supporting part  158  may be provided on a lower portion of the pin body  150   b . The supporting part  158  may be configured to support the length adjusting part  152 . As an example, the supporting part  158  may extend in a length direction of the socket pin  150 , and the first portion  154  of the length adjusting part  152  may be inserted in the supporting part  158 . Since the supporting part  158  supports the first portion  154  in the length direction of the socket pin  150 , movement of the first portion  154  in a horizontal direction may be restricted. Accordingly, it is possible to more easily align the socket pin  150  to the test substrate  180 . However, in certain embodiments, the supporting part  158  may be omitted. The socket pin  150  may be provided to sequentially pass through the slider  120 , the base  110 , the stopper  160 , the lead guide  170 , and the test substrate  180 . 
         [0036]    Referring back to  FIGS. 3A to 3C , the stopper  160  may be provided in the base  110 . The stopper  160  may be provided to have third through holes  162 . The socket pins  150  may be inserted into the third through holes  162 , and thus, the socket pins  150  may be fastened by the stopper  160 . The lead guide  170  may be provided in the base  110 . The lead guide  170  may be provided below the stopper  160 . The lead guide  170  may include fourth through holes  172 . The socket pins  150  may be inserted in the fourth through holes  172 . The lead guide  170  may be configured to protect the socket pin  150 . 
         [0037]    A top surface of the test substrate  180  may be provided to have a recess region  181 . The second terminal  182  may be provided in the recess region  181 . For example, the top surface of the test substrate  180  may be formed to have a difference in height. A magnitude of pressure applied to the socket pin  150  may be dependent on a height of the top surface of the test substrate  180  that is in contact with each socket pin  150 . Accordingly, it is possible to allow each socket pin  150  to have a variable length. That is, the length of the socket pins  150  may vary according to a contour of the test substrate  180  and, in particular, structures of the test substrate  180  contacting the socket pins  150 . Since the resistant force is applied to the length adjusting part  152 , the socket pin  150  may be restored to its initial length when the pressure applied to the socket pin  150  is removed. Accordingly, if the test process is finished, only the test substrate  180  may be discarded, and the socket pin  150  may be re-used. In addition, in some embodiments, one or more of the recess regions  181  do not include a through hole extending through the test substrate  180 . As a result, electrical connections within the test substrate  180  and/or on an opposite side of the substrate may be more easily routed. 
         [0038]      FIGS. 5A and 5B  are diagrams schematically illustrating a reduction in length of a socket pin  150 , which occurs when the socket pin  150  is in contact with the test substrate  180 .  FIGS. 6A and 6B  are diagrams schematically illustrating restoration of the socket pin  150  to an initial length, which may occur when the socket pin  150  is separated from the test substrate  180 . In other words,  FIGS. 5A and 5B  illustrate a process, in which a distance between the bottom surface of the pin body  150   b  and the length adjusting part  152  is reduced, and  FIGS. 6A and 6B  illustrate a process, in which the distance between the bottom surface of the pin body  150   b  and the length adjusting part  152  is restored. Referring to  FIGS. 5A and 5B , in the case where a pressure is applied to the length adjusting part  152  by the test substrate  180 , the length adjusting part  152  may be upwardly moved along its length direction. In some embodiments, the length adjusting part  152  may distort. Here, the hook-shaped portion of the second portion  156  may be inserted between pin head supporting part  150   ab  and is compressed. However, when the second portion  156  is a rigid body and is forcedly inserted between the pin head supporting parts  150   ab , a resistant force may be applied to the second portion  156  from the pin head supporting parts  150   ab  as the second portion  156  distorts. For example, the resistant force may be restoring force. Accordingly, referring to  FIGS. 6A and 6B , if the pressure from the test substrate  180  is removed, the length adjusting part  152  may be restored to its initial position by a resistant force applied to the second portion  156 . Although a particular configuration of a rigid structure has been used as an example, in other embodiments, any rigid structure that results in a force applied to the length adjusting part  152  in a direction that returns the length adjusting part  152  to its initial position may be used. 
         [0039]    Although not shown, the test socket  105  may further include a latch (not shown). The latch (not shown) may be configured to immobilize the semiconductor substrate P provided in the base  110 . In certain embodiments, the test socket  105  may include an adaptor  140 . Also, some elements of the test socket  105  may be omitted or modified. 
         [0040]    The socket pin  150  may be used for transmission of test signals. According to some embodiments, the socket pin  150  may be configured to have an adjustable length and to be detachable from the test substrate  180 . Also, it may be unnecessary to form fifth through holes (e.g., see  18   a  of  FIG. 1B ) in the test substrate  180 , and since the second terminals  182  are formed in accordance with positions of the socket pins  150 , it is possible to simplify a process of fabricating the test substrate  180 . In addition, since there is no necessity to connect the socket pins  150  to the test substrate  180 , it is possible to re-use the socket pins  150 . Furthermore, since the socket pin  150  has an adjustable length, the socket pin  150  can be used to perform a test process on various types of semiconductor devices. 
         [0041]      FIG. 7A  is a perspective view illustrating a socket pin  150 ′ according to some embodiments.  FIGS. 7B and 7C  are diagrams schematically illustrating a process of changing a length of the socket pin  150 ′ of  FIG. 7A . In the following description of the socket pin  150 ′, an element previously described with reference to  FIGS. 4A and 4C  may be identified by a similar or identical reference number without repeating an overlapping description thereof. 
         [0042]    Referring to  FIGS. 7A to 7C , the length adjusting part  152   a  may have the first portion  154  and a rotation member  157 . The first portion  154  may include at least a portion protruding from the bottom surface of the pin body  150   b . For example, a lower portion of the first portion  154  may protrude from the bottom surface of the pin body  150   b . The rotation member  157  may be coupled to the pin body  150   b . The rotation member  157  may be provided to face the first portion  154 . 
         [0043]    In some embodiments, the rotation member  157  may include the rotation bar  157   a  coupled to the pin body  150   b  and the rotation axis  157   b  provided at substantially a center of the rotation bar  157   a . The rotation bar  157   a  may be configured to rotate about the rotation axis  157   b . An end portion of the first portion  154  may be provided to face a side of the rotation bar  157   a.    
         [0044]    In a particular example, the rotation member  157  may be rotatably attached to the pin body  150   b  such that when rotated as illustrated in  FIG. 7C , the rotation member  157  applies a force to the first portion  154  in a direction opposite to the rotation. Accordingly, in the case where a pressure from the test substrate  180  is applied to the first portion  154 , the first portion  154  may be upward moved to cause rotation of the rotation bar  157   a . This may lead to a reduction in total length of the socket pin  150 ′. By contrast, in the case where the pressure is removed, the rotation bar  157   a  and the first portion  154  may be restored to their initial state. To enhance the restoration of the rotation bar  157   a , the rotation bar  157   a  may be provided to have a weight greater than that of the first portion  154 . A material, size, or weight of the rotation bar  157   a  may be changed to more effectively control a length of the length adjusting part  152   a . Although a particular configuration of a rotating structure has been used as an example, in other embodiments, any rotating structure that will apply a force to the first portion  154  in a direction that returns the first portion  154  to its initial position may be used. 
         [0045]      FIG. 8A  is a perspective view illustrating a socket pin  150 ″ according to some embodiments.  FIGS. 8B and 8C  are diagrams schematically illustrating a process of changing a length of the socket pin  150 ″ of  FIG. 8A . In the following description of the socket pin  150 ″, an element previously described with reference to  FIGS. 4A and 4C  may be identified by a similar or identical reference number without repeating an overlapping description thereof. 
         [0046]    Referring to  FIGS. 8A to 8C , the length adjusting part  152   b  may have the first portion  154  and an elastic element  159 . The first portion  154  may include at least a portion protruding from the bottom surface of the pin body  150   b . For example, a lower portion of the first portion  154  may protrude from the bottom surface of the pin body  150   b . The elastic element  159  may be coupled to the pin body  150   b . The elastic element  159  may be provided to face the first portion  154 . For example, the elastic element  159  may be formed of an insulating material; however, in other embodiments, the elastic element  159  may be formed of a conducting material, a material that conducts under pressure, or the like. If the test substrate  180  applies a pressure to an end portion of the first portion  154 , the first portion  154  may be moved in an upward direction, and thus, an opposite end portion of the first portion  154  may contact and compress the elastic element  159 . Accordingly, the elastic element  159  may be pushed by the first portion  154 , and thus, a total length of the socket pin  150 ″ may be reduced. In the case where there is no pressure between the first portion  154  and the elastic element  159 , the elastic element  159  may be restored and the first portion  154  may be moved to its initial position. Although the first portion  154  is illustrated to have a bar shape and the opposite end portion thereof is illustrated to be in contact with the elastic element  159 , the shape of the opposite end portion of the first portion  154  may be variously changed. For example, as shown in  FIG. 4A , the opposite end portion of the first portion  154  may be shaped like a hook. Although a particular configuration of an elastic structure has been used as an example, in other embodiments, any elastic structure that will apply a force to the first portion  154  in a direction that returns the first portion  154  to its initial position may be used. 
         [0047]    Although, in the above examples, the length adjusting parts  152 ,  152   a , and  152   b  are described to have a resilient structure, a rotatable structure, or an elastic structure, shapes and structures of the length adjusting parts  152 ,  152   a , and  152   b  may not be limited thereto in other embodiments. For example, the total length of the socket pin may be adjusted by other structures (e.g., a hinge connection structure or a pivot structure). Although the second terminals of the test substrate are described to have a recessed structure, the second terminals may be provided to have a structure protruding from the top surface of the test substrate. 
         [0048]    According to some embodiments, forming through holes in a test substrate may not be necessary. In other words, since terminals on the test substrate are formed based on positions of socket pins, it is possible to simplify a process of fabricating the test substrate. In addition, there is no necessity to connect the socket pins to the test substrate, and thus, it is possible to re-use the socket pins. Furthermore, since the socket pin has an adjustable length, the socket pin can be used to perform a test process on various types of semiconductor devices. 
         [0049]    While particular embodiments have been illustrated and described, it will be understood by one of ordinary skill in the art that variations in form and detail may be made therein without departing from the spirit and scope of the attached claims.