Abstract:
A socket assembly for testing semiconductor devices includes a socket board electrically connected to an outside testing device, and a socket guide which covers the socket board. The socket guide has an open part to receive the semiconductor device and allows pins on the semiconductor device to couple with connection pins on the socket board. A spacer may be interposed between the socket board and the socket guide to maintain a predetermined distance between the semiconductor device and the socket board. In this manner, the balls or the leads of each semiconductor device may be pressed onto connection pins of the socket to a predetermined depth, even when the semiconductor devices have different thicknesses.

Description:
This application claims the benefit of the Patent Korean Application No. P2005-07975, filed on Jan. 28, 2005, which is hereby incorporated by reference as if fully set forth herein. 
     BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates to a testing semiconductor device, and more particularly, to a socket assembly for testing semiconductor device. 
     2. Discussion of the Related Art 
     Generally, memory or non-memory semiconductors are released after various testing steps when manufactured. A handler is a device used to transfer and test semiconductors in the testing process. Commonly, in a handler, when trays, therein semiconductors being stored, are stacked in a loading stacker, a picker robot transfers semiconductors which will be tested to a test site and connects them to a test socket, thereby performing a predetermined test, and again the picker robot transfers the devices which tested completely to an unloading stacker and repeatedly performs a process for classifying them in the predetermined tray based on testing results. 
       FIG. 1  is a sectional view illustrating that a semiconductor of a conventional handler is connected to a socket assembly. 
     Shown in  FIG. 1 , a conventional socket assembly for testing semiconductors comprises a socket board  10  wherein a plurality of connecting pins  11  electrically connected to a tester of an outer testing device is formed, a socket guide  20  secured to cover the socket board  10  on an upper side of the socket board  10 . An open part  21  is formed in the center of the socket guide  20  in order that a semiconductor (S) may move toward the socket board  10 . 
     The semiconductor (S) is connected to connection pins  11  of the socket board  10 , being mounted on a carrier  50  disposed in a test tray (not shown) at a predetermined distance.  51  (no description) is a latch securing/detaching the semiconductor (S) on/from the carrier  50 . 
     Accordingly, a separate transportation device transfers a test tray (not shown), and then lines up each carrier  50  in an outer side of the socket assembly. In succession, when a press unit  60  outside presses each carrier  50  at predetermined power, a lower surface of each carrier  50  touches an upper surface of a socket guide  20  and simultaneously the semiconductor (S) mounted on each carrier  50  is connected to a socket board  10 , thereby performing a testing. 
     However, the structure connecting a conventional semiconductor (S) to a socket board  10  of a socket assembly has the following problems. 
     First, in case that a thickness of each semiconductor for being tested is varied, each carrier  50  each semiconductor (S) mounted thereon should be replaced, thereby causing a problem of increasing a cost. 
     In other words, balls (B) of each semiconductor are pressed in a predetermined depth by a press unit  60 . However, although the semiconductors are the same kind, each semiconductor body and each mold part, may be thicker or thinner in a process of manufacturing. When the thicknesses of the semiconductors are various, the strength applied when the balls of each semiconductor are pressed to the connection pins is various, thereby causing a problem that the balls of each semiconductor may be damaged and/or the testing may not be performed well due to a poor connection. 
     Therefore, conventionally the strength applied when the balls of each semiconductor are pressed to the connection pins is controlled by adjusting the thickness of the portion where the semiconductor (S) of each carrier  50  is seated. In that case, it is almost impossible to adjust the thickness by manufacturing all the carriers respectively, so that the carriers of each tray are replaced with carriers having each thickness corresponding to each semiconductor. 
     Generally, in case of a handler for testing memory semiconductors, more than 10 test trays are used in one handler and 63 carriers are installed in each tester. Thus when all carriers should be replaced, the cost may increase and may take a longer time to replace the carriers, thereby causing a problem that the testing efficiency may deteriorate. 
     Second, there are many cases that a semiconductor may have a bending in order that a center of the semiconductor may be convex, compared with edges of the semiconductor, thereby causing a problem that balls in a center of each semiconductor are not connected well to connection pins of an assembly socket. 
     Conventionally, the balls in the center of each semiconductor are firmly connected to the connection pins of the socket by a press unit for pressing the semiconductor heavily. 
     However, when the press unit presses the semiconductor heavily, the connection in the center of the semiconductor is completely performed, but a problem may be arise that the balls or the connection pins may be damaged because it presses the edges too much. 
     SUMMARY OF THE INVENTION 
     Accordingly, the present invention is directed to a socket assembly for testing semiconductor device that substantially obviates one or more problems due to limitations and disadvantages of the related art. 
     An object of the present invention is to provide a socket assembly for testing semiconductor device, wherein leads or balls of a semiconductor is/are pressed into connection pins of a socket in a predetermined depth without replacing carriers and etc, thereby preventing the semiconductor and the socket from being damaged and enhancing reliability of testing. 
     Another object of the present invention is to provide a socket assembly for testing semiconductor device capable of firmly connecting a semiconductor to a socket without pressing with too much force in spite of a bending of a semiconductor 
     Additional advantages, objects, and features of the invention will be set forth in part in the description which follows and in part will become. apparent to those having ordinary skill in the art upon examination of the following or may be learned from practice of the invention. The objectives and other advantages of the invention may be realized and attained by the structure particularly pointed out in the written description and claims hereof as well as the appended drawings. 
     To achieve these objects and other advantages and in accordance with the purpose of the invention, as embodied and broadly described herein, a handler for testing semiconductor device including carriers for detachably securing semiconductors, a socket assembly wherein each semiconductor is electrically connected and testing is performed, and a press unit for connecting each semiconductor to the socket assembly by pressing the carriers toward the socket assembly. And a socket assembly of a handler comprises a socket board electrically connected to a testing device outside, wherein a plurality of connection pins connected to leads of a semiconductor is provided; a socket guide mounted to cover the socket board, with an open part formed on a first side thereof so that the semiconductor may be in/out, thereby connected to connection pins of the socket; and a spacer interposed between the socket board and the socket guide for maintaining a predetermined distance between the semiconductor and the socket board, touching an surface of the semiconductor having moved into an inside of the socket guide. 
     According to the present invention, when a semiconductor mounted on each carrier is inserted into an inside of a socket guide and connected to connection pins, the surface of the semiconductor touches the spacer before a carrier touches a socket guide. Therefore, the semiconductor and the socket board may maintain a predetermined distance regardless of the semiconductor thickness, thereby the semiconductor capable of being connected to the connection pins of the socket board in a predetermined depth. 
     It is to be understood that both the foregoing general description and the following detailed description of the present invention are exemplary and explanatory and are intended to provide further explanation of the invention as claimed. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The accompanying drawings, which are included to provide a further understanding of the invention and are incorporated in and constitute a part of this application, illustrate embodiment(s) of the invention and together with the description serve to explain the principle of the invention. In the drawings: 
         FIG. 1  illustrates a sectional view of a conventional socket assembly for testing semiconductor device; 
         FIG. 2  illustrates an exploded perspective view of a socket assembly for testing semiconductor device according to a first preferred embodiment of the present invention; 
         FIG. 3  illustrates a cut-away perspective view of a socket assembly of  FIG. 2 ; 
         FIGS. 4 and 5  illustrate sectional views of key parts each describing that each semiconductor having a different thickness is connected to a socket assembly of  FIG. 2 ; 
         FIG. 6  illustrates an exploded perspective view of a second preferred embodiment of a socket assembly according to the present invention; 
         FIGS. 7 and 8  illustrate sectional views of key parts each describing that each semiconductor having a different thickness is connected to a socket assembly of  FIG. 6 ; 
         FIG.9  illustrates an exploded perspective view of a third preferred embodiment of a socket assembly for testing semiconductor device according to the present invention. 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     Reference will now be made in detail to the preferred embodiments of the present invention, examples of which are illustrated in the accompanying drawings. Wherever possible, the same reference numbers will be used throughout the drawings to refer to the same or like parts. 
     In description of preferred embodiments, a semiconductor for being tested is a BGA type semiconductor, wherein a plurality of balls is formed on a first surface thereof. However, a socket assembly of the present invention may be similarly applied to various kinds of semiconductors besides a BGA type semiconductor. 
     To help understanding, same reference codes are used in the constitutional elements of a socket assembly of the present invention same as ones of a conventional socket assembly. 
     Referenced to  FIGS. 2 through 5 , a first embodiment of a socket assembly for testing semiconductor device according to the present invention will be described in the followings. 
     Shown in  FIGS. 2 and 3 , a socket assembly of the present invention comprises a socket board  10  wherein a plurality of connection pins  11  is formed, a socket guide  20  formed to cover an upper side of the socket board  10 , and a spacer  100  contactablely supporting a semiconductor (S) having moved into an inner side space of the socket guide  20  between the socket guide  20  and the socket board  10 . 
     Carriers  50  are formed in a test tray (not shown) at a predetermined distance in plural, for example  64  carriers, and each carrier  50  is employed to keep a semiconductor (S) temporarily in a test tray. 
     A seating part  50   a  therein a semiconductor (S) seated is formed on a center of a lower surface of each carrier  50 , and a pair of latches  51  for securing/detaching the semiconductor (S) and an operation button  52  moving up/down for operating the latches  51  are formed in both sides of each carrier  50 . The operation button  52  is elastically supported by a compressed spring (not shown). 
     Each latch  51  of each carrier  50  is rotatablely fastened about a hinge shaft  53 . Also, a guide groove  54  is formed in an inclined long circle shape in the center of the latch  51 . A guide pin  55  is secured to the carrier  50  in the guide groove  54   
     Thus, when the operation button  52  is pressed from outside, the operation button  52  moves down against an elasticity of the compressed spring (not shown). Then the latch  51  is rotoated outward and there is space between the latch  51  and the semiconductor (S), thereby detaching the semiconductor (S). 
     On the contrary, when the outside force having pressed the operation button  52  is removed, the operation button  52  returns to its original location by the elasticity of the compressed spring (not sown). Then, the latch  51  is rotated inward by guiding of the guide pin  55 , thereby securing the semiconductor (S). 
     An open part  21  is formed in a center of a socket guide  20  of the socket assembly so as that a semiconductor (S) may approach to a socket board  10 . Also, guide parts  22  in a cone shape inserted into guide holes  56  are formed projected upward at the two corners of an upper surface of the socket guide  20 . When the carrier  50  approaches to the socket guide  20 , each guide part  22  is inserted into each guide hole  56  of the carrier  50  and employed to guide the carrier  50  to its accurate location in the socket guide  20 . 
     The connection pins  11  of the socket board  10  are electrically connected to a tester of an outside testing device and the number and the pitch of the connection pins  11  are corresponding to those of the balls (B) of the semiconductor (S). 
     The spacer  100  is formed in a center portion in a plate shape, therein an open part  101  is formed so as that the connection pins  11  of the socket board  10  may be passed through together. In both sides of the open part  101  latch escape holes  102  are formed, being passed through so as that the latches  50  of the carrier  50  may be inserted therein. 
     The spacer  100  may be made of various kinds of materials such as metal, however it is preferable but not necessary that the spacer  100  is made of a resin material such as plastic. 
     The spacer  100  touches a surface of a semiconductor (S) just before or at the moment that a lower surface of the carrier  50  touches an upper surface of a socket guide  20  when connecting a semiconductor (S) to connection pins  11 . Thus, the spacer  100  is employed as a kind of a hard stopper so that the semiconductor (S) may maintain a predetermined distance with the socket board  10 , in other words, so that the balls (B) of the semiconductor (S) may be pressed to the connection pins  11  in a predetermined depth. 
     Therefore, the spacer  100  is formed thick enough that the balls (B) of the semiconductor (S) may be pressed to the connection pins  11  in a predetermined depth at the same time that the spacer  100  may touch a surface of the semiconductor (S). 
     The size of the socket guide  20 , the spacer  100  and the carrier  50  may be set up by the size that the spacer  100  is capable of touching the surface of the semiconductor (S) just before or at the moment that the carrier  50  touches the surface of the socket guide  20 , on a basis of the thinnest of all semiconductors (S) for being tested. 
     If the size of the socket guide  20 , the spacer  100  and the carrier  50  is set up on a basis of the semiconductor which is thick or thicker, testing the thicker semiconductors is performed well. However when testing the thinnest semiconductor, the carrier  50  touches the socket guide  20  before the semiconductor (S) touches the spacer  100 , thereby the balls (B) of the semiconductor (S) may not be connected deep enough or not be connected at all. 
     The detailed description of an operation of the socket assembly is the following. 
       FIG. 4  describes a connection state when testing a thinner semiconductor. 
     As shown in  FIG. 4 , when a separate transportation device moves a test tray (not shown) and lines up carriers  50  in an outer side of a socket assembly, a press unit  60  outside presses each carrier  50  at a predetermined power and then a semiconductor (S) mounted on each carrier  50  moves toward a socket board  10  through a open part  21  of a socket guide  20 . 
     In succession, at the moment that balls (B) of the semiconductor (S) are connected to connection pins  11  of the socket board  10 , edge portion of the ball forming surface are supported, touching the spacer  100 , thereafter the semiconductor (S) maintaining a predetermined distance with the socket board  10 . At this time a lower surface of the carrier  50  is closely adjacent to an upper surface of the socket guide  20 . 
     As shown in  FIG. 5 , in case of testing a thicker semiconductor than the semiconductor of  FIG. 4 , a surface of a semiconductor (S) is supported, touching a spacer  100  when a semiconductor being connected to the connection pins  11 , thereby the distance between the semiconductor (S) and the socket board  10  being the same as the distance illustrated in  FIG. 4 . That is, the semiconductor (S) is pressed to the connection pins  11  in a predetermined depth. 
     However, since the semiconductor (S) is thicker, the gap (g) between the lower surface of the carrier  50  and the socket guide  20  is increased as much as the thickness of the semiconductor (S) increased. 
     According to the present invention, when the semiconductor (S) is connected to the connection pins  11 , the semiconductor (S) is supported, touching the spacer  100  first and then the carrier  50  touches the socket guide  20 , resulting in the semiconductor (S) maintaining a predetermined distance with the socket board  10 . Accordingly, the semiconductors (S) may be connected to the connection pins  11  at a predetermined distance all the time even if the semiconductors have various thicknesses. 
     Also, as shown in  FIG. 4 , Edges of a semiconductor (S) are pressed and at the same time supported by a spacer  100 . Thereby, the semiconductor (S) may be connected in a straight flat state though a bending of a semiconductor (S) occurs. Accordingly, it is possible to press the entire area of the semiconductor (S) uniformly without applying too much force to the semiconductor (S), 
       FIGS. 6 through 8  describe a second embodiment of the present invention. 
     A socket assembly according to the second embodiment, similar to the socket assembly according to the first embodiment as mentioned above, comprises a socket board  10 , a socket guide  20 , and a spacer  110 . 
     In the socket board  10 , a plurality of connection pins is formed and the socket guide  20  is mounted to cover the socket board  10 . The spacer  110  is interposed between the socket board  10  and the socket guide  20  for contactably supporting a surface of a semiconductor (S). 
     There is a difference between the socket assembly according to the second embodiment and the socket assembly according to the. first embodiment in a structure of the spacer  110 . That is, in the center of the spacer  110  of the second embodiment according to the second embodiment, a plurality of pass through holes  111  is formed so that the connection pins  11  could be inserted respectively. 
     Thus, as shown in  FIGS. 7 and 8 , when a semiconductor (S) is connected to a socket board  10 , each ball (B) of the semiconductor (S) is connected to connection pins  11  through each pass through hole  111  and the entire area of the semiconductor (S) except the area of the balls (S) is supported, touching an upper surface of the spacer  110 . Thereby, the semiconductor (S) is capable of maintaining a predetermined distance with the socket board  10 , so that the semiconductor (S) may be connected to the connection pins  11  in a predetermined depth. 
     Moreover, in the socket assembly according to the second embodiment, since the connection pins  111  are respectively inserted into each pass through hole  111  of the spacer  110 , the arrangement among the spacer  110 , the socket board  10  and the socket guide  20 , when mounting the spacer  110  on an upper surface of the socket board  10 , is precisely performed and it is needed to prevent the spacer  110  from moving after the arrangement. 
     Thus, a socket assembly according to the present invention further comprises a location decision unit including two location decision pins  25 , two location decision holes  115 , and two location decision recesses  15 . 
     The two location decision pins  25  are perpendicularly formed at diagonal corners of an inner side of the socket guide  20  and the two location decision holes  115  are formed, passed through, at diagonal corners of the spacer  110  corresponding to the two location decision pins  25 . The two location decision recesses  15  are formed at diagonal comers of the socket board  10  corresponding to the two location decision holes  115 . 
     The location decision pins  25  of the socket guide  20  passes through the location decision holes  115  of the spacer  110  and the location decision recesses  15  of the socket board  10  in order, so that it is possible to perform the precise arrangement when assembling the socket assembly and to prevent the location from being moved during the test. 
     On the other hand, in the socket assembly of each above embodiment, the spacer is formed in a single unit in a plate shape. However, as shown in  FIG. 9 , the spacers  120  may be formed divided in plural so as to touch the area except the area of the balls (B) of a semiconductor (S). 
     A plurality of guide projections  18  may be formed on an upper surface of the socket board  10  for guiding the installation location of each spacer  120 . 
     In the embodiments of the present invention, each spacer is formed, separated from the socket board, however it may be formed, united in a single unit to the socket board. 
     Accordingly, the present invention has the following advantageous effects. 
     First, when a semiconductor is connected to connection pins, a semiconductor is supported, touching a spacer first before a carrier touches a socket guide, so that the semiconductor may maintain a predetermined distance with the socket board, thereby the semiconductor connected to the connection pins in a predetermined depth in spite of various thicknesses of the semiconductors. Thus, it is not needed to replace carriers according to the thicknesses of the semiconductors. thereby reducing an expense and time caused by replacing carriers. 
     Second, since edges of a semiconductor are pressed, supported by a spacer, the semiconductor is connected in a straight flat state although a bending of a semiconductor occurs. Therefore, the entire area of the semiconductor may be uniformly pressed without applying too much force to the semiconductor. 
     It will be apparent to those skilled in the art that various modifications and variations can be made in the present invention without departing from the spirit or scope of the inventions. Thus, it is intended that the present invention covers the modifications and variations of this invention provided they come within the scope of the appended claims and their equivalents.