Abstract:
Disclosed is a handler for testing a semiconductor device, which is used when testing the fabricated semiconductor device. The handler for testing a semiconductor device includes a stacker to supply and accommodate a customer tray and a position selecting device to move the stacker and select a position of the stacker. By efficiently operating the stacker, the handler is able to continuously handle a large amount of semiconductor devices in a same testing process or continuously handle semiconductor devices in different lots, and equipment is prevented from becoming larger or having more complex designs so that required space, production costs and manpower are reduced and operating rates are improved.

Description:
BACKGROUND OF THE INVENTION 
       [0001]    1. Field of the Invention 
         [0002]    The present invention relates to a handler for testing a semiconductor device, which is used when testing a fabricated semiconductor device, and more particularly, to a handler for receiving and supplying a customer tray. 
         [0003]    2. Description of the Related Art 
         [0004]    A handler for testing a semiconductor device (hereinafter, referred to as handler) withdraws semiconductor devices fabricated through a predetermined fabricating process from a customer tray, electrically connects the semiconductor devices to a tester, and when the test is completed, classifies the semiconductor devices according to the test result to insert the semiconductor devices into the empty customer tray. 
         [0005]    The handler have evolved into various forms such as the form proposed in Korean Unexamined Patent Publication No. 10-2009-0012667 or in Korean Unexamined Patent Publication No. 10-2002-0077596 according to a purpose of uses such as a type of the semiconductor device, the purpose of the test or an environment. 
         [0006]    In general, the handler includes multiple stackers to receive and supply the customer tray, in which the semiconductor device is loaded or can be loaded. 
         [0007]    The multiple stackers include a supplying stacker to supply the customer tray in which the semiconductor device to be tested is loaded, and an accommodating stacker to accommodate the customer tray in which the semiconductor device is loaded after the test is completed. In this case, at least one supplying stacker and at least one accommodating stacker are provided. In addition, a predetermined number of customer trays may be accommodated in the supplying stacker or the accommodating stacker. 
         [0008]    Meanwhile, the semiconductor devices are tested under the same environmental condition in a unit of one lot. Therefore, it is preferable to continuously test the semiconductor devices in the unit of one lot. 
         [0009]    However, the quantity of semiconductor devices in the unit of one lot occasionally exceeds the quantity of semiconductor devices loadable in the customer trays that may be accommodated in the supplying stacker. In this case, when the test of some semiconductor devices in the one lot is completed, a worker supplies the customer tray in which the remaining semiconductor devices are loaded. Therefore, the manpower of the worker is consumed, and the operating rate of the handler decreases due to the above work. 
         [0010]    Therefore, instead of fabricating the handler  100  having one supplying stacker  171  and one withdrawing position WP, at which the semiconductor device is withdrawn as illustrated in  FIG. 1 , an improved handler  200  including supplying stackers  271   a  and  271   b  and withdrawing positions WP 1  and WP 2  may be considered. However, according to the improved handler  200 , not only does the size of equipment become larger, but the design and control of a device moving unit  200  for withdrawing and moving the semiconductor device from the customer tray CT at the withdraw positions WP 1  and WP 2  become complex. 
         [0011]    In addition, because the handler disclosed in Patent Applications Nos. 10-2013-0052809 and 10-2013-0055510, which have been filed by the applicant, includes a structure to move the customer tray loaded in the stacker to the withdrawing position by a lower belt, an additional belt structure is required when multiple supplying stackers are provided. 
         [0012]    Therefore, spaces are wasted and fabrication costs are increased. Further, when the semiconductor devices are fabricated in a normal quantity, the additional supplying stacker  271   b  is rarely utilized. 
         [0013]    It may also be considerable to increase a vertical height of the stacker for increasing a loading quantity of the customer trays which are vertically loaded in the stacker, but this increases the size of the equipment, and the customer tray loading work of the worker becomes cumbersome due to the increased height of the equipment. 
       SUMMARY OF THE INVENTION 
       [0014]    An object of the present invention is to provide a technology for appropriately dealing with a quantity variation of semiconductor devices to be tested by improving the operability of a stacker. 
         [0015]    To achieve the object, a handler for testing a semiconductor device according an embodiment of the present invention includes: a test supporting part to withdraw a semiconductor device loaded in a customer tray at a withdrawing position to electrically connect the semiconductor device to a tester, and insert the semiconductor device into the customer tray at an inserting position after a test of the semiconductor device is completed by the tester; and a customer tray receiving and supplying part to move the customer tray, in which the semiconductor device to be tested is loaded, to the withdrawing position or move the customer tray, in which the semiconductor device is loaded after the test is completed, from the inserting position to support a smooth movement of the semiconductor devices in association with an operation of the test supporting part, wherein the customer tray receiving and supplying part includes: a plurality of supplying stackers to accommodate the customer tray to be moved to the withdrawing position; a first tray moving device to move the customer tray loaded in the supplying stackers to the withdrawing position; a position selecting device to move the supplying stackers so that one of the supplying stackers is positioned at a supplying position (a position to move the customer tray to the withdrawing position); at least one accommodating stacker to accommodate the customer tray positioned at the inserting position; and at least one second tray moving device to move the customer tray at the inserting position to the at least one accommodating stacker. 
         [0016]    A number of the supplying stackers may be more than a number of the withdrawing positions, and the customer tray loaded in the supplying stackers may be moved to a same withdrawing position through the first tray moving device. 
         [0017]    The supplying stackers may include a detecting sensor to detect whether the customer tray is loaded, and the position selecting device may select the supplying stacker, in which the customer tray exists, and move the supplying stacker to the supplying position when the detecting sensor detects that the supplying stacker in the current supplying position has no customer tray. 
         [0018]    To achieve the object, a handler for testing a semiconductor device according to another embodiment of the present invention includes: a test supporting part to withdraw a semiconductor device loaded in a customer tray at a withdrawing position to electrically connect the semiconductor device to a tester, and insert the semiconductor device into the customer tray at an inserting position after a test of the semiconductor device is completed by the tester; and a customer tray receiving and supplying part to move the customer, in which the semiconductor device to be tested is loaded, to the withdrawing position or move the customer tray, in which the semiconductor device is loaded after the test is completed, from the inserting position, wherein the customer tray receiving and supplying part includes: multiple stackers, in which the customer tray to be moved to the withdrawing position is loaded or the customer tray moving from the inserting position is accommodated; a plurality of tray moving devices to move the customer tray loaded in at least one of the stackers to the withdrawing position, and move another at least one of the stackers from the inserting position; and a position selecting device to move at least one of the stackers to select a position of the at least one stacker. 
         [0019]    At least one of the stackers may include one of a first detecting sensor to detect whether the customer tray is full and a second detecting sensor to detect whether the customer tray is loaded, and wherein the position selecting device moves at least one of the stackers based on information detected by the first detecting sensor and the second detecting sensor. 
         [0020]    According to the present invention, the handler for testing a semiconductor device may have the following effects due an efficient operation of the stacker. 
         [0021]    First, a large amount of semiconductor devices can be continuously tested in the same test process. 
         [0022]    Second, the wasted space and production costs can be reduced by preventing an enlargement or a complex design of equipment. 
         [0023]    Third, manpower can be saved and an operating rate can be improved. Fourth, the semiconductor devices in mutually different lots can be continuously tested. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0024]      FIG. 1  and  FIG. 2  are views for explaining limitations of typical handlers. 
           [0025]      FIG. 3  is a schematic plan view of a handler for testing a semiconductor device according to an embodiment of the present invention. 
           [0026]      FIG. 4  is a schematic perspective view of a main part of the handler. 
           [0027]      FIG. 5  is a reference view for explaining an operation of the handler. 
       
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
       [0028]    Hereinafter, an exemplary embodiment according to the present invention is described with reference to the drawings. For a concise description, repetitive descriptions are omitted or summarized. 
         [0029]      FIG. 3  is a schematic plan view of a handler  300  according to an embodiment of the present invention. 
         [0030]    As illustrated in  FIG. 3 , the handler  300  according to the present invention includes a pair of loading plates  311  and  312 , a first device moving unit  320 , a pair of test shuttles  331  and  332 , a connecting device  340 , a second device moving unit  350 , a tray moving device  360 , a first supplying stacker  371   a,  a second supplying stacker  371   b,  first accommodating stackers  372   a,    372   b  and  372   c,  a second accommodating stacker  373 , a standby stacker  374 , a first tray moving device  381 , second tray moving devices  382   a,    382   b  and  382   c,  a third moving device  383 , a fourth tray moving device  384  and a position selecting device  390 . 
         [0031]    Semiconductor devices may be loaded on the loading plates  311  and  312 . The loading plates  311  and  312  may have a heater. Therefore, the loaded semiconductor devices may be heated to a temperature required for a test. An operation of the heater is interrupted when testing at a room temperature. 
         [0032]    The first device moving unit  320  withdraws the semiconductor device from a customer tray CT at a withdrawing position WP and loads the semiconductor device on the loading plates  311  and  312 . In addition, the first device moving unit  320  moves the semiconductor device on the loading plates  311  and  312  to the test shuttles  331  and  332  positioned to the left in the drawing. The first device moving unit  320  is movable in the transverse direction and the longitudinal direction (refer to dotted arrows a and b). 
         [0033]    The test shuttles  331  and  332  may load the semiconductor device. 
         [0034]    The test shuttles  331  and  332  may move in the transverse direction and pass through a test position TP (refer to dotted arrows c 1  and c 2 ). 
         [0035]    The connecting device  340  electrically connects the semiconductor device loaded in the test shuttles  331  and  332  at the test position TP to a test socket TS&#39; below the test position TP. In this case, the electrical connection between the semiconductor device and the test socket TS&#39; is performed by the connecting device  340  pressing the semiconductor device loaded on the test shuttles  331  and  332 . The semiconductor device is electrically connected to the tester through the test socket TS&#39;. 
         [0036]    The second device moving unit  350  inserts the semiconductor devices in the test shuttles  331  and  332 , which are positioned to the right in the drawing, into the customer tray CT at a retesting position RP, an inserting position IP, and a fixing position FP while classifying the semiconductor devices according to the test result after the test is completed. The retesting position RP is a position at which the semiconductor device to be retested is inserted into the customer tray. The inserting position (IP) is a position at which the semiconductor device, which passed the test, is inserted into the customer tray CT. The fixing position FP is a position at which the semiconductor devices excluding the semiconductor, which passed the test or is to be retested, are inserted into the customer tray. The second device moving unit  350  is movable in the transverse direction and the longitudinal direction (refer to dotted arrows d and e). Roles or mutual positions of the retesting position RP, the inserting position IP and the fixing position FP may be varied according to needs of users. 
         [0037]    The tray moving device  360  moves the customer tray CT between a withdrawing position WP, an accommodating position AP, the retesting position RP, the inserting position IP and a standby position SP. The tray moving device  360  is movable in the transverse direction (refer to dotted arrow f). 
         [0038]    The pair of loading plates  311  and  312 , the first device moving unit  320 , the pair of test shuttles  331  and  332 , the connecting device  340 , the second device moving unit  350  and the tray moving device  360  may be grouped as a test supporting part. That is, the test supporting part withdraws the semiconductor device loaded in the customer tray CT at the withdrawing position WP to electrically connect the semiconductor device to the tester, and inserts the semiconductor device to the customer tray CT at the inserting position IP while classifying the semiconductors according to the test result after the test is completed. 
         [0039]    Structures of the stackers of the first supplying stacker  371   a , the second supplying stacker  371   b,  the first accommodating stackers  372   a,    372   b  and  372   c,  the second accommodating stacker  373 , the standby stacker  374 , and structures of the tray moving devices such as the first tray moving device  381 , the second tray moving devices  382   a ,  382   b  and  382   c,  the third moving device  383 , the fourth tray moving device  384  are disclosed in Patent Application Nos. 10-2013-0052809 and 10-2013-0055510, which have been filed by the applicant. Therefore, a detailed description of the structure and operations of the stackers and the moving devices are omitted in the following description. 
         [0040]    The first supplying stacker  371   a  and the second supplying stacker  371   b  accommodates the customer tray CT in which the semiconductor device is loaded. 
         [0041]    One lot of semiconductor devices is separately loaded on multiple customer trays CT. In addition, the customer trays CT are separately accommodated in the first supplying stacker  371   a  and the second supplying stacker  371   b.    
         [0042]    Or, the customer tray, in which the lot of semiconductor devices to be tested first is loaded, may be accommodated in the first supplying stacker  371   a,  and the customer tray, in which the lot of semiconductor devices to be tested later is loaded, may be accommodated in the second supplying stacker  371   b.    
         [0043]    The customer trays CT stacked on the first supplying stacker  371   a  and the second supplying stacker  371   b  are moved to the withdrawing position WP one at a time by the first tray moving device  381 . 
         [0044]    As illustrated in  FIG. 4 , the first supplying stacker  371   a  and the second supplying stacker  371   b  are transversely arranged side by side in adjacent to each other. The first supplying stacker  371   a  and the second supplying stacker  371   b  are coupled to each other. Therefore, the first supplying stacker  371   a  and the second supplying stacker  371   b  move together in the transverse direction. When the first supplying stacker  371   a  and the second supplying stacker  371   b  are capable of loading each of the customer trays CT, respectively, any form or structure such as being adjacent with each other, spaced apart from each other, etc. are possible. 
         [0045]    The first supplying stacker  371   a  and the second supplying stacker  371   b  include clampers CP to support or release the support of the vertically stacked customer trays CT. 
         [0046]    The clamper CP includes a supporting member PE and a cylinder CD. 
         [0047]    The supporting member PE supports the customer tray CT. 
         [0048]    The cylinder CD horizontally moves the supporting member PE back and forth. Therefore, the customer tray CT, on which the supporting member PE is stacked, maybe supported or the support may be released. The cylinder CD may be replaced by a motor, etc. 
         [0049]    Three or more supplying stackers may be provided according to embodiments. In addition, each supplying stacker may not be coupled to each other and may be individually moved. That is, various variations of the supplying stackers to be moved may exist. 
         [0050]    The first supplying stacker  371   a  and the second supplying stacker  371   b  include a first detecting sensor FS to detect whether the customer tray CT is fully loaded. In addition, the first supplying stacker  371   a  and the second supplying stacker  371   b  include a second detecting sensor TS to identify whether the customer tray CT is loaded. 
         [0051]    In reference, the symbol SA illustrated below the first supplying stacker  371   a  in  FIG. 4  illustrates a supporting apparatus. The supporting apparatus SA supports the customer tray CT when the clamper CP releases the support of the customer tray CT. The supporting apparatus SA includes a supporting plate SP and an up and down device UD. The supporting plate SP supports the customer tray CT. The up and down device UD elevates the supporting plate SP. The supporting apparatus SA is also provided below each of the first accommodating stackers  372   a,    372   b  and  372   c,  the second accommodating stacker  373  and the standby stacker  374 . The supporting apparatus SA is involved in an operation of moving the stacked customer trays CT to a rear side. The supporting device SA below the first supplying stacker  371   a  is involved in the movement of the customer tray CT stacked in the second supplying stacker  371   b.  The technology related to the movement of the customer tray CT is described in detail in  FIG. 8  to  FIG. 17  in the Patent Application No. 10-2013-0055510, which has been filed by the applicant. Therefore, a detailed description is omitted. 
         [0052]    The first accommodating stackers  372   a,    372   b  and  372   c  accommodate the customer tray CT moving from the retesting position RP or the inserting position IP by an operation of the second tray moving devices  382   a,    382   b  and  382   c.    
         [0053]    The second accommodating stacker  373  accommodates the customer tray CT passing through the accommodating position AP after all of the semiconductor devices loaded at the withdrawing position WP are withdrawn by the first device moving unit  320 . 
         [0054]    The standby stacker  374  accommodates the empty customer trays CT to be supplied to the standby position SP, at which the customer tray CT to be moved to the retesting position RP or the inserting position IP are standing by. That is, the empty customer tray CT accommodated and loaded in the standby stacker  374  is moved to the standby position SP one at a time by the fourth tray moving device  384 . In addition, the customer tray CT at the standby position SP is moved to the retesting position RP or the inserting position IP by the tray moving device  360 . 
         [0055]    The first tray moving device  381  moves the customer tray CT accommodated and loaded in the first supplying stacker  371   a  or the second supplying stacker  371   b  to the withdrawing position WP one at a time. 
         [0056]    The second tray moving devices  382   a,    382   b  and  382   c  move the customer tray CT at the retesting position RP or the inserting position IP to the first accommodating stackers  372   a,    372   b  and  372   c.    
         [0057]    The third tray moving device  383  moves the customer tray CT at the accommodating position AP to the second accommodating stacker  373 . 
         [0058]    The fourth tray moving device  384  moves the empty customer tray CT accommodated in the standby stacker  374  one at a time to the standby position SP. 
         [0059]    The position selecting device  390  moves the first supplying stacker  371   a  and the second supplying stacker  371   b,  which are mutually coupled, in the transverse direction. Therefore, the first supplying stacker  371   a  is positioned at a supplying position PP or the second supplying stacker  371   b  is positioned at the supplying position PP. In this case, the supplying position PP is a position, from which the customer tray CT stacked in the first supplying stacker  371   a  and the second supplying stacker  371   b  is moved to the withdrawing position WP. The position selecting device  390 , as illustrated in  FIG. 4 , includes a cylinder  391 , a pair of guiders  392   a  and  392   b,  a moving member  393 , a stopper  394 , an absorber  395  and a position detecting sensor  396 . 
         [0060]    The cylinder  391  provides a moving force for moving the first supplying stacker  371   a  and the second supplying stacker  371   b  in the transverse direction. The cylinder  391  may be replaced by various driving units such as a motor, etc. which may move the first supplying stacker  371   a  and the second supplying stacker  371   b  in the transverse direction. The guiders  392   a  and  392   b  guide the first supplying stacker  371   a  and the second supplying stacker  371   b  to move in the transverse direction. 
         [0061]    The moving member  393  is coupled to the first supplying stacker  371   a  and the second supplying stacker  371   b.  In addition, the moving member  393  is movably coupled to the guiders  932   a  and  392   b.  Furthermore, the moving member  393  moves in the transverse direction according to the guide of the guiders  392   a  and  392   b.  Therefore, the moving member  393  moves together with the first supplying stacker  371   a  and the second supplying stacker  371   b.    
         [0062]    The stopper  394  prevents the first supplying stacker  371   a  and the second supplying stacker  371   b  from excessively moving. 
         [0063]    The absorber  395  is coupled to the stopper  394 . The absorber  395  absorbs an impact and shock between the moving member  393  and the stopper  394 . 
         [0064]    The position detecting sensor  396  detects which one of the first supplying stacker  371   a  and the second supplying stacker  371   b  is positioned at the supplying position PP. That is, the position detecting sensor  396  detects the stacker of the first supplying stacker  371   a  and the second supplying stacker  371   b  from which the customer tray CT is supplied to the withdrawing position WP. 
         [0065]    The position detecting sensor  395  makes it possible to identify whereabouts of the supply currently being supplied. For example, when the customer trays CT, on which the semiconductor devices of mutually different lots are loaded, are separately stacked in the first supplying stacker  371   a  and the second supplying stacker  371   b , respectively, which lot of semiconductor devices are currently supplied to the test supporting part may be identified by the position detecting sensor  396 . In the embodiment, the position detecting sensor  396  detects the position of the moving member  393 . However, according to embodiments, the position detecting sensor  396  may detect whether a load of the cylinder is moving back and forth. In addition, the position detecting sensor may be installed in the stopper. In addition, the position sensor may be separately installed in the supplying position PP, the first supplying stacker  371   a  and the second supplying stacker  371   b  such that the position of the first supplying stacker  371   a  and the second supplying stacker  371   b  is sensed by a mutual recognition. 
         [0066]    The first supplying stacker  371   a,  the second supplying stacker  371   b,  the first accommodating stacker  372   a,    372   b  and  372   c,  the second accommodating stacker  373  and the standby stacker  374  or the first tray moving device  381 , the second tray moving device  382   a,    382   b  and  382   c,  the third tray moving device  383  and the fourth tray moving device  384  may be grouped as a tray accommodating part. That is, the tray accommodating part assists smooth movements of the semiconductor devices according to the operation of the test supporting part by supplying or accommodating the customer tray CT. 
         [0067]    Hereinafter, a method of testing the handler  300  including the above configuration will be described. 
         [0068]    First, as illustrated in  FIG. 3 , while the first supply stacker  371   a  is positioned at the supplying position PP, the first tray moving device  381  moves the customer tray CT stacked in the first supplying stacker  371   a  to the withdrawing position WP one at a time. 
         [0069]    The first device moving unit  320  withdraws the semiconductor device to be tested from the customer tray CT at the withdrawing position WP to load the semiconductor device in the loading plates  311  and  312 . In addition, the first device moving unit  320  moves the semiconductor device loaded in the loading plates  311  and  312  to the test shuttles  331  and  332  positioned at the left and loads the semiconductor device on the test shuttles  331  and  332 . 
         [0070]    The test shuttles  331  and  332 , in which the semiconductor device to be tested is loaded, moves to the right and is positioned at the testing position TP. The connecting device  340  presses the semiconductor device loaded in the test shuttle  331  and  332  at the testing position downward. Therefore, the semiconductor device is electrically connected to the test socket TS&#39;. In addition, the semiconductor device is tested. 
         [0071]    When the test is completed, the electrical connection between the semiconductor device and the test socket TS&#39; is released, and the test shuttles  331  and  332  further move to the right. The second moving device  350  withdraws the semiconductor device from the test shuttles  331  and  332  positioned at the right after the test is completed. In addition, the second moving device  350  inserts the semiconductor devices into the customer tray at the retesting position RP, the inserting position IP and the fixing position FP while classifying according to the test result. 
         [0072]    Meanwhile, the customer tray CT, from which all of the semiconductor devices loaded at the withdrawing position WP are withdrawn, is moved to the accommodating position AP by the tray moving device  360 . In addition, the customer tray CT at the accommodating position AP is moved to and stored in the second accommodating stacker  373  by the third tray moving device  383 . 
         [0073]    In addition, when the customer tray CT at the retesting position RP and the inserting position IP is filled with the semiconductor devices, the customer tray CT at the retesting position RP and the inserting position IP is moved to and stored in the first accommodating stackers  372   a,    372   b  and  372   c  by the second tray moving devices  382   a ,  382   b  and  382   c.  Accordingly, the customer tray CT is removed from the retesting position RP and the inserting position IP. The fourth tray moving device  384  moves an empty customer tray CT from the standby stacker  374  to the standby position SP in advance. In addition, the empty customer tray CT at the standby position SP is moved to the retesting position RP or the inserting position by the tray moving device  360 . According to embodiments, the empty customer tray CT at the withdrawing position WP may be moved to the standby position SP by the tray moving device  360 , and the empty customer tray CT at the withdrawing position WP may be directly moved to the retesting position RP or the inserting position IP. 
         [0074]    By the process, every semiconductor device loaded in the customer tray CT accommodated in the first supplying stacker  371   a  is supplied to the test supporting part. In addition, the second detecting sensor TS of the first supplying stacker  371   a  detects whether all of the customer trays CT are emptied from the first supplying stacker  371   a.  When the first supplying stacker  371   a  is completely emptied, as illustrated in  FIG. 5 , the position selecting device  390  is operated to move the positions of the first supplying stacker  371   a  and the second supplying stacker  371   b  so that the second supplying stacker  371   b  is positioned at the supplying position PP. Accordingly, the customer tray CT accommodated in the second supplying stacker  371   b  is moved to the withdrawing position WP one at a time by the first tray moving device  381 . 
         [0075]    Meanwhile, when the customer tray CT of the first supplying stacker  371   a  is emptied, the position selecting device  390  is operated such that a notification is provided while positioning the second supplying stacker  371   b  at the supplying position PP. In this case, a user who hears the notification may stack the customer tray CT, in which the semiconductor device to be tested is loaded, in the first supplying stacker  371   a.    
         [0076]    In addition, when the first supplying stacker  371   a  at the supplying position PP has no customer tray, whether the customer tray CT exists at the second supplying stacker  371   b  is identified. When the customer tray CT exists at the second supplying stacker  371   b , the position selecting device  390  moves the second supplying stacker  371   b  to the supplying position PP. When the customer tray CT is not in the second supplying stacker  371   b,  only an alarm is generated. 
         [0077]    Furthermore, when there are three or more supplying stackers and the supplying stacker in the current supplying position has no customer tray, whether the supplying stacker having the customer tray among the other supplying stackers exist is identified. In addition, the supplying stacker having the customer tray is moved to the supplying position. 
         [0078]    In addition to the embodiments, the present invention may be applied to the standby stacker or the accommodating stacker to allow a variety of operations of the stackers. 
         [0079]    When a movement of the accommodating stacker is taken into consideration, different from the supplying stacker, the accommodating stacker is moved when the accommodating stacker is filled with the customer tray. In this case, the sensor to detect whether the accommodating stacker is full of the customer tray is operated. 
         [0080]    In addition, moving three or more stackers together may be taken into consideration. Further, moving each of the stacker individually may be taken into consideration. 
         [0081]    Furthermore, the handler of the present invention may be applied to the handlers having the test supporting part in a form different from the test supporting part of the embodiment. 
         [0082]    That is, the handler of the present invention may be effectively applied when the number of corresponding stackers is more than the withdrawing position WP, the accommodating position AP, the retesting position RP, the inserting position IP and the standby position SP. 
         [0083]    While the present invention has been particularly shown and described by embodiments with reference to the accompanied drawings, it should not be interpreted in any way to limit the scope of the present invention. Therefore, the scope of the present invention is not limited to the described embodiments, but is limited only by the accompanying claims and equivalents thereof, and any alterations equivalent to the accompanying claims are within the scope of the present invention.