Abstract:
A test tray includes a rectangular shaped frame and a plurality of transport modules to receive a plurality of semiconductor devices. A precise location-determining unit mounted on both sides of the frame to precisely determines and fixes the test tray location. According to one embodiments, the precise location-determining unit includes a locking hole to receive a positioner, a bushing to prevent locking hole wear, a protection bar to cover the frame and the bushing. The test tray prevents yield reduction and handler malfunction, e.g., sudden stopping of the handler, by precisely fixing tray and semiconductor device position during loading, unloading, and testing. The test tray can be extensively without repair or replacement because locking hole, with protective bushing therein, enjoys little or no wear.

Description:
CROSS-REFERENCE TO RELATED PATENT APPLICATION 
   This application claims the benefit of Korean Patent Application No. 10-2005-0018427, filed on Mar. 5, 2005, in the Korean Intellectual Property Office, the disclosure of which is incorporated herein in its entirety by reference. 
   BACKGROUND 
   1. Field of the Invention 
   The present invention relates to a test tray used in a handler transporting semiconductor devices such as during semiconductor device testing. 
   2. Description of the Related Art 
   In general, semiconductor devices, e.g., semiconductor integrated circuits or ICs including memory semiconductor devices, non-memory semiconductor devices, and module ICs in which such semiconductor devices are mounted on a single substrate in a circuit manner, are shipped after being tested. Accordingly, semiconductor device testing is an important manufacturing process wherein yield, e.g., percentage of manufactured devices passing testing procedures and available for shipping, is determined. A handler is an apparatus used to automatically test the semiconductor devices. 
   A handler includes a test tray. The test tray is used when loading a semiconductor device, when transferring the semiconductor device as loaded thereon to a test head, when directly testing the loaded semiconductor device in the test head, or when unloading the semiconductor device following testing. 
   The location of the test tray must be precisely determined when a semiconductor device is tested in the test head or when a semiconductor device is loaded upon or unloaded from the test head. If the location of the test tray is not precisely determined, the yield of tested semiconductor devices may be inaccurately low. For example, a false failure may be indicated due to imprecise positioning of the semiconductor device during testing and an otherwise viable device may be lost. Also, the handler may malfunction or suddenly stop functioning due to imprecise positioning and production rates may fall. 
   Accordingly, handler operation, especially test tray positioning, can affect product yield and production rates. 
   SUMMARY 
   Embodiments of the present invention provide a test tray that can be used continuously with precisely determined location when semiconductor devices are loaded, unloaded, and tested. According to embodiments of the present invention, a test tray includes a position-determining formation engaged by a compatible formation adjacent to and along the movement direction of the tray to fix the tray in position during loading, unloading, and testing procedures. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
     The above and other features and advantages of the present invention will become more apparent by describing in detail exemplary embodiments thereof with reference to the attached drawings in which: 
       FIG. 1  is a plan view illustrating a handler for testing semiconductor devices, according to an embodiment of the present invention; 
       FIG. 2  is a perspective view illustrating a method of determining the location of a test tray included in the handler of  FIG. 1 ; 
       FIG. 3  is a perspective view of a test tray according to an embodiment of the present invention; 
       FIG. 4  is an exploded perspective view of a precise location-determining unit of the test tray of  FIG. 3 ; 
       FIG. 5  is an enlarged view of a precise location-determining unit of the test tray of  FIG. 3 ; 
       FIG. 6  is a cross-sectional view of the precise location determining unit of  FIG. 5 ; and 
       FIGS. 7 and 8  are perspective views respectively illustrating a wearing state of a locking hole without and with, respectively, a bushing in the locking hole. 
   

   DETAILED DESCRIPTION 
   Embodiments of the present invention will now be described more fully with reference to the accompanying drawings. The invention may, however, be embodied in many different forms and should not be construed as being limited to the particular embodiments set forth herein; rather, these embodiments are provided as through and complete disclosure and will fully convey the present invention to those skilled in the art. 
     FIG. 1  is a plan view illustrating a handler for testing semiconductor devices according to an embodiment of the present invention, and  FIG. 2  is a perspective view illustrating a method of determining the location of a test tray included in the handler of  FIG. 1 . 
   More specifically, referring to  FIG. 1 , a test tray  100  is used for transferring semiconductor devices  11 . The test tray  100  according to an embodiment of the present invention can be used for loading (mounting) a plurality of semiconductor devices  11 , for directly testing the semiconductor devices  11 , and for unloading the semiconductor devices  11  after testing. In the subsequent descriptions, the use of a precise location-determining unit  130  for precisely determining a location of the test tray  100  under or in relation to the test head part is described, but it will be understood that the precise location-determining unit  130  can be used for a supply unit and a discharge unit, e.g., in transport applications other than positioning relative to a test head part. 
   The test tray  100  is first disposed in the supply unit. The plural semiconductor devices  11  are loaded on each of a plurality of transport modules  110  in the test tray  100 . The test tray  100 , on which the semiconductor devices  11  are loaded, is transferred to a test head part, e.g., moving left-to-right in the view of  FIG. 1  and right-to-left in the view of  FIG. 2 . The test tray  100  is thereby transferred along a movement or transfer path by a driving force supplied from a motor  17  on a conveyor belt  19  in a movement direction indicated by an arrow in  FIGS. 1 and 2 , and is initially stopped by a protrusion portion  12  of an end part of a stopper  13  selectively locatable in front of a leading portion  21  of the tray  100 . The protrusion portion  12  of the end part of the stopper  13  moves back and forth, e.g., as a plunger movement, with respect to the stopper  13 . 
   The location of the test tray  100 , as initially stopped by the stopper  13 , is further precisely determined and fixed by a precise location-determining unit  130  mounted on both sides of the test tray  100  and a positioner  15 . A locking hole  140 , depicted in  FIG. 2 , is included in the precise location-determining unit  130  of the test tray  100 , and the location of the test tray  100  is precisely determined and fixed by inserting a pin-shaped protrusion portion  14  of an end part of the positioner  15  into the locking hole  140 . The protrusion portion  14  of the positioner  15  is formed in a conical shape for easy insertion into the locking hole  140 . The protrusion portion  14  of the positioner  15 , or the entire positioner  15 , can selectively move back and forth. 
   The test tray  100  can be continuously used, e.g., without frequent maintenance or replacement, since a bushing  145  ( FIGS. 4 and 5 ) located in hole  140  prevents or substantially reduces wear of the locking hole  140 . If the bushing  145  is worn or damaged, the bushing  145  can be replaced without need to replace the entire test tray  100 . Therefore, the test tray  100  can be used through extended periods without intervening maintenance or replacement procedures possibly affecting production rates. 
   When a precise location of the test tray  100  is determined, a test for the semiconductor devices  11  loaded on the test tray  100  is performed. The test of the semiconductor devices  11  is performed by electrically contacting sockets or pin cards (not shown) located on a lower part of the test tray  100 , e.g., by pressing the test tray  100  downward. A plurality of semiconductor devices  11  are tested simultaneously by mounting a plurality of electrically contacting portions between the sockets and the semiconductor devices  11 . 
   With the protrusion portion  14  of the positioner  15  inserted into the locking hole  140 , the test can be stably performed in a fixed state of the test tray  100 . The test tray  100 , on which the tested semiconductor devices  11  remain loaded, is transferred to a discharge unit. The semiconductor devices  11  are then unloaded according to a classification of viable and failed devices. 
     FIG. 3  is a perspective view illustrating a test tray according to an embodiment of the present invention, and  FIG. 4  is an exploded perspective view of a precise location-determining unit of the test tray of  FIG. 3 .  FIG. 5  is an enlarged view of a precise location-determining unit of the test tray of  FIG. 3 , and  FIG. 6  is a cross-sectional view of the precise location determining unit of  FIG. 5 . 
   Referring to  FIG. 3 , a test tray  100  according to an embodiment of the present invention comprises a rectangular shaped frame  105 , horizontal bars  120  formed to cross both sides of the frame  105  to define a plurality of regions, a plurality of transport modules  110  along the horizontal bar  120 , and a tray recognition unit  125  mounted on a surface of the frame  105 . Reference numeral  115  in the transport modules  110  indicates a semiconductor device-inserting unit on which semiconductor devices  11  (not shown in  FIG. 3 ) are loaded. 
   The precise location determining units  130 , that precisely determine the location and fix the test tray  100 , is mounted on both side portions  23  (see  FIG. 2 ) of the test tray  100 . The precise location-determining units  130 , as depicted in  FIG. 2 , are located relative to, e.g., along, a direction parallel to the moving direction of the test tray  100  within a handler system. 
   The precise location-determining unit  130  is composed of a locking hole  140  in the frame  105 , a bushing  145  that is inserted in the locking hole  140  to prevent wearing of the locking hole  140 , a protection bar  135  that covers the frame  105  and the bushing  145 , and a connection hole  142  ( FIG. 4 ) and a bolt  150  that couples the protection bar  135  and the frame  105 , e.g., attaches the protection bar  135  to the frame  105 . The protection bar  135  is coupled to the frame  105  by being inserted into a concave area on each side of the frame  105 . 
   The bushing  145  is formed, for example, of a polymer containing carbon fiber. Thus, the compressive strength and stiffness of the bushing  145  can be increased and the expansion coefficient of the bushing  145  can be reduced. Also, the bushing  145  can have high wearing resistance, high load carrying capability, and high thermal conductivity. 
   Also, as described above, the location of the test tray  100  is precisely determined and fixed since a positioner  15  (see  FIG. 2 ) is inserted into the locking hole  140  of the precise location-determining unit  130 . In this manner, precise location-determining unit  130  and positioner  15  act as first and second locking formations each positionable relative to the other and mutually engagable to fix a selected position of the frame along the movement direction of the test tray  100 . Furthermore, the test tray  100  can be continuously used since the bushing  145  prevents the locking hole  140  from wear. 
     FIGS. 7 and 8  are perspective views respectively illustrating an undesirable wearing state of the locking hole  140  without a bushing  145  ( FIG. 7 ) and an improved state of reduced or no wear when the bushing  145  is mounted in the locking hole  140  ( FIG. 8 ). 
   Referring to  FIGS. 7 and 8 , when the bushing  145  is mounted in the locking hole  140  of the precise location determining unit  130  of the test tray  100  according to embodiments of the present invention, as indicated by the reference numeral  160  in  FIG. 8 , the wearing of the locking hole  140  does not occur. However, as indicated by the reference numeral  155  in  FIG. 7 , when no bushing  145  is mounted in the locking hole  140 , the locking hole  140  is severely damaged, especially irregularly damaged. Therefore, if the bushing  145  is inserted into the locking hole  140  of the precise location-determining unit  130  of the test tray  100 , the test tray  100  can be continuously used, e.g., without intervening repair or replacement, since the wearing of the locking hole  140  is prevented. 
   As described above, a test tray according to some embodiments of the present invention includes a precise location-determining unit that can precisely determine and fix the test tray on both side units of a frame in a direction parallel to the moving direction of the test tray in a handler. The precise location-determining unit includes a locking hole into which a positioner can be inserted, a bushing that can prevent the locking hole from wearing, a protection bar that covers the frame and the bushing, and a connection hole and a bolt to couple the protection bar to the frame. 
   Therefore, the test tray according to some embodiments of the present invention can solve conventional problems, such as a reduced yield, malfunction or sudden stopping of the handler, since a position of the test tray can be precisely determined when semiconductor devices are loaded, unloaded, and tested. 
   Furthermore, the test tray according to some embodiments of the present invention can be continuously used since the locking hole is prevented from wear by inserting a bushing into the locking hole when the locations of the test tray are precisely determined at a test head part, a supply unit, or a discharge unit. 
   While the present invention has been particularly shown and described with reference to exemplary embodiments thereof, it will be understood by those of ordinary skill in the art that various changes in form and details may be made therein without departing from the spirit and scope of the present invention as defined by the following claims.