Abstract:
An apparatus for transferring semiconductor devices in a semiconductor device handler is provided which simplifies set up procedures when a species of device to be tested, and the associated change kit, is changed. A reference picker and three variable pickers are positioned within the framing structure of the handler, with the motion of the third variable picker synchronized relative to the motion of the first and second variable pickers. A plurality of sensors determine an initial position of the variable pickers, and then motion of the variable pickers is monitored by respective scanning heads and linear scales until a new setup position which corresponds to the new device species is attained. In this manner, the procedure and structure for varying position and pitch of the various pickers can be simplified, thus reducing processing time and cost.

Description:
This application claims the benefit of the Korean Application No. P2001-80160 filed on Dec. 17, 2001, which is hereby incorporated by reference. 
   BACKGROUND OF THE INVENTION 
   1. Field of the Invention 
   The present invention relates to an apparatus for picking up to transfer semiconductor devices in a handler for testing the semiconductor devices, and more particularly, to an apparatus for transferring semiconductor devices in a semiconductor device test handler enabling to facilitate to vary pitches of pickers for picking up the semiconductor devices to correspond to a tray and change kits according to species and sizes of the semiconductor devices to be tested. 
   2. Discussion of the Related Art 
   Generally, semiconductor devices produced in a production line undergo tests for checking whether to be good or fail before shipment. 
   A handler is a device for testing such semiconductor devices. The handler uses a semiconductor device transferring apparatus to transfer semiconductor devices received on a tray to another site in the course of a process automatically, loads the semiconductor devices on a test socket of a test site to carry out a demanded test thereon, and classifies the tested semiconductor devices into various grades to unload them on the tray. The handler carries out such steps repeatedly to perform the tests. 
     FIG. 1  illustrates a layout of a general handler for semiconductor device test. 
   Referring to  FIG. 1 , in a front part of a handler body  1 , formed are a loading unit  2  on which trays receiving test-expecting semiconductor devices thereon are loaded and an unloading unit  3  having a plurality of trays receiving test-completed semiconductor devices classified into good products and re-examining products in accordance with test results. And, a soaking plate  7  is installed in rear of the loading unit  2 . The soaking plate  7  includes a heating means (not shown in the drawings) and a cooling means(not shown in the drawings) inside to heat or cool the test-expecting semiconductor devices to a predetermined temperature for temperature test. 
   And, a reject multi-stacker  5 , on which a plurality of trays are loaded to receive the semiconductor devices classified by grade into the failed products according to the test results, is installed in rear of the unloading unit  3 . 
   In a test site  10  located at the foremost rear part of the handler body  1 , a test socket  11  connected electrically to an external testing device is installed to test a performance of each of the semiconductor devices. Over the test sockets  11 , formed are first and second index heads  12   a  and  12   b  installed to move horizontally to pick up to load the semiconductor devices; which are transferred to standby positions at both sides of the test sockets  11 , on the test sockets  11  as well as to pick up to retransfer the tested semiconductor devices on the test sockets  11  to the standby positions at both sides. 
   In the very front of the test site  10 , first and second loading shuttles  8   a  and  8   b  are installed to move back and forth. The first and second loading shuttles  8   a  and  8   b  receive to transfer the semiconductor devices from the loading unit  2  or the soaking plate  7  to the standby positions at both sides of the test sockets  11  of the test site  10 . At one sides of the first and second loading shuttles  8   a  and  8   b , first and second unloading shuttles  9   a  and  9   b  are installed to move back and forth, respectively. The fist and second unloading shuttles  9   a  and  9   b  receive to transfer the test-completed semiconductor devices from the test site  10  to an outside of the test site  10 . 
   Fixing frames  13  are installed at the front end of the handler body  1  and over the very front side of the test site  10  across the handler body  1 , respectively. A pair of movable frames  14   a  and  14   b  are installed at the fixing frames  13  to move right and left along the fixing frames  13 . And, loading and unloading pickup device  15  and  16  are installed at the movable frames  14   a  and  14   b  to move back and forth along the movable frames  14   a  and  14   b  to pick up semiconductor devices, respectively. Each of the loading and unloading pickup devices  15  and  16  includes a plurality of pickers (not shown in the drawings) to transport a plurality of the semiconductor devices simultaneously. 
   Meanwhile, a handler is constituted to carry out a test on such semiconductor devices as QFP, BGA, SOP, and the like. After one species of the semiconductor devices have been tested, another species of the semiconductor devices are tested. In such a case, a change kit including the tray, soaking plate  7 , loading shuttles  8   a  and  8   b , unloading shuttles  9   a and  9   b , test socket  11 , and the like is replaced by another change kit fitting to the semiconductor device species to carry out the test. 
   In this case, since the change kits replaced according to the species of the test-expecting semiconductor devices differ from each other in pitches and sizes of landing units where the semiconductor devices land, pitches of the pickers of the loading and unloading pickup devices  15  and  16  should be varied to fit those of the landing units. 
   However, the loading and unloading pickup devices  15  and  16  according to the related art use driving means including mechanical links, belts, ball screws, and servomotors, and the like to vary their pickers, respectively. Hence, the driving means are too complicated to change a rotary motion into a straight motion to increase their overall volumes, whereby power consumption increases. 
   Moreover, when the belts and pulleys are used, tensions of the belts should be adjusted periodically. Besides, the operating belts and pulleys raise dust to have bad influence on the semiconductor devices. 
   SUMMARY OF THE INVENTION 
   Accordingly, the present invention is directed to an apparatus for transferring semiconductor devices in a semiconductor device that substantially obviate one or more problems due to limitations and disadvantages of the related art. 
   An object of the present invention is to provide an apparatus for transferring semiconductor devices in a semiconductor device enabling to simplify the structure for varying pickers for picking up semiconductor devices as well as accomplish fast and precise variation of the pickers. 
   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, an apparatus for transferring semiconductor devices in a handler according to the present invention includes rectangular frames installed movably on a handler body, stators of two linear motors installed on inner sides of two of the frames adjacent to each other, respectively, movers of the two linear motors installed to move along the stators, respectively, a reference pickup member fixed to an inner corner between the frames where the linear motors meet each other to pick up the semiconductor device, first and second pickup members coupled with the movers of the linear motors to move along the frames, respectively, a first guide member fixed to the first pickup member to be in parallel with the frame having the second pickup member installed thereat, a second guide member fixed to the second pickup member to be vertical the first guide member, and a third pickup member coupled with both of the first and second guide members to move along the second and first guide members by movements of the first and second pickup members. 
   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 layout of a general handler for semiconductor device test; 
       FIG. 2  illustrates a bird&#39;s-eye view of an apparatus for transferring semiconductor devices according to a first embodiment of the present invention excluding a frame in part; 
       FIG. 3  illustrates a bird&#39;s-eye view of a picker driving unit of the transferring apparatus in  FIG. 2 ; 
       FIG. 4A  and  FIG. 4B  illustrate layouts for explaining operation of an apparatus for transferring semiconductor devices according to the present invention; and 
       FIG. 5  illustrates a bird&#39;s-eye view of an apparatus for transferring semiconductor devices according to a second embodiment of 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 the following description, a constitution of a handler, to which an apparatus for transferring semiconductor devices according to the present invention is applied, refers to that of the handler according to the related art and its detailed description is skipped. 
     FIG. 2  illustrates a bird&#39;s-eye view of an apparatus for transferring semiconductor devices according to a first embodiment of the present invention excluding a frame in part,  FIG. 3  illustrates a bird&#39;s-eye view of a picker driving unit of the transferring apparatus in  FIG. 2 , and  FIG. 4A  and  FIG. 4B  illustrate layouts for explaining operation of an apparatus for transferring semiconductor devices according to the present invention. 
   Rectangular frames  101  are fixed to movable frames  14   a  and  14   b  (cf.  FIG. 1 ). Stators  102   a  and  104   a  and movers  102   b  and  104   b  of two linear motors  102  and  104  are installed at both neighboring inner sides of the frames  101 , respectively. And, the movers  102   b  and  104   b  are coupled under the stators  102   a  and  104   a  with LM blocks  103   a  and  105   a  of LM guides  103  and  105  installed in parallel with the frame to move along the LM guides  103  and  105 , respectively. 
   A fixing block  110  is fixed to a corner between the frames  101  where the stators  102   a  and  104   a  of the linear motors  102  and  104  meet each other, and a reference picker  120  picking up a semiconductor device is fixed to the fixing block  110 . 
   ‘L’ type first and second movable blocks  111  and  112  are fixed to the movers  102   b  and  104   b  of the linear motors  102  and  104 , respectively. And, first and second variable pickers  121  and  122  picking up another semiconductor devices are installed at the first and second movable blocks  111  and  112 , respectively. 
   Moreover, a first guide member  108  is fixed to one side of the first movable block  111  to be in parallel with the linear motor  104  having the second variable picker  122  installed thereat, and a second guide member  109  is fixed to one side of the second movable block  112  to be in parallel with the linear motor  102  having the first variable picker  121  installed thereat. The first guide member  108  is installed to a level lower than that of the second guide member  109 , whereby such that the first and second guide members  108  and  109  do not meet. 
   A third movable block  113 , to which a third variable picker  123  picking up a semiconductor device is fixed, is coupled with both of the first and second guide members  108  and  109 . When the first movable block  111  moves, the third movable block  113  moves along the second guide member  109 . When the second movable block  112  moves, the third movable block  113  moves along the first guide member  108 . 
   The reference picker  120  and the first to third variable pickers  121 ,  122 , and  123  are constructed to have the same shapes, and include cylinders  120   a ˜ 123   a  fixed to the fixing block  110  and the moving blocks  111 ,  112 , and  113 , respectively and nozzle head units  120   b ˜ 123   b  installed at lower ends of the cylinders  120   a ˜ 123   a  to move upward and downward to absorb the semiconductor devices by vacuum suction, respectively. 
   Meanwhile, a plurality of hall sensors  106  of magnetic field sensors are installed at lower ends of the frames  101  having the stators  102   a  and  104   a  of the linear motors  102  and  104  installed thereat to leave a predetermined interval from each other. Hence, the hall sensors  106  detect the current positions of the first and second variable pickers  121  and  122  before the linear motors  102  and  104  are driven. And, sensing pieces  107  extending toward a plurality of the hall sensors  106  are coupled with lower ends of the movers  102   b  and  104   b  of the linear motors  102  and  104 , respectively to be detected by the hall sensors  106 . 
   Moreover, in order to precisely control the movements of the movers  102   b  and  104   b  of the linear motors  102  and  104  by detecting displacements of the first and second variable pickers  121  and  122  when the linear motors  102  and  104  are driven, linear scales  131  and  133  are fixed to upper ends of the movers  102   b  and  104   b  of the linear motors  102  and  104 , respectively and scanning heads  132  and  134  encoding numerical values of the linear scales  131  and  133  are installed on upper ends of the frames  101  having the linear motors  102  and  104  installed thereat, respectively. 
   And, a pair of limit sensors  143  and  144  are installed on the upper ends of the frames  101  to prevent overrun of the pickers by restricting final moving ranges of the first and second variable pickers  121  and  122 . The limit sensors  143  and  144  are used for a home checking operation as well. The home checking operation is carried out to set the moving ranges of the variable pickers  121 ,  122 , and  123  and transfer them to a control unit (not shown in the drawings) by initially moving the first and second variable pickers  121  and  122  and the third variable picker  123  interoperating with them from the closest points to the farthest points of operation after the apparatus for transferring the semiconductor devices have been loaded on the handler. 
   Operation of the above-constituted apparatus for transferring the semiconductor devices is explained as follows. 
   After one species of the semiconductor devices has been tested, if another species of the semiconductor devices is to be tested, the change kits on which the respective devices are mounted should be replaced in accordance with the corresponding sizes and species of the semiconductor devices as well as the pitches of the pickers  120  to  123  of the apparatus for transferring the semiconductor devices should be varied to correspond to pitches of the replacing change kits, respectively. 
   Once a user inputs specifications of the replacing change kits to the unit (not shown in the drawings) of the handler, the control unit checks the current positioning statuses of the first and second variable pickers  121  and  122  by the hall sensors  106  installed at the frames  101  and then drives the linear motors  102  and  104  to move the variable pickers  121 ,  122 , and  123  a set amount from the current positions so as to be disposed at the required positions. 
   Namely, having detected the current positions of the first and second variable pickers  121  and  122  on the frames  101 , the control unit (not shown in the drawings) drives the linear motors  102  and  104 . The first and second variable pickers  121  and  122  are then guided by the LM guides  103  and  105  to move away in setup directions, respectively. In this case, the third variable picker  123  is synchronized by the movements of the first and second variable pickers  121  and  122  to move along the second and first guide members  109  and  108 . 
   When the first and second variable pickers  121  and  122  move as the movers  102   b  and  104   b  of the linear motors  102  and  104  move, the scanning heads  132  and  134  encode to transfer the displacements of the linear scales  131  and  133  attached to the respective movers  102   b  and  104   b  to the control unit (not shown in the drawings). Thus, the control unit enables to monitor the displacements of the first and second variable pickers  121  and  122  continuously. Hence, when the first and second variable pickers  121  and  122  reach the demanded positions, the control unit (not shown in the drawings) stops operating the linear motors  102  and  104 , thereby enabling to transfer the first to third variable pickers  121  to  123  to the demanded positions exactly. 
   It is preferable to drive a pair of the linear motors  102  and  104  simultaneously for time reduction. Yet, the linear motors can be driven sequentially with a time difference as well. 
     FIG. 5  illustrates a bird&#39;s-eye view of an apparatus for transferring semiconductor devices according to a second embodiment of the present invention, in which the transferring apparatus includes a pair of pickers. 
   Referring to  FIG. 5 , a fixing block  210  is fixed to one end of a base plate  201  fixed to movable frames of a handler. A reference picker  220  with a cylinder  220   a  and nozzle head unit  220   b  is installed at the fixing block  210 . And, a stator  202  and a mover  203  are installed at the base plate  201  to a side of the fixing block  210 . 
   In this case, the mover  203  of the linear motor is coupled with an LM guide  205  installed in parallel with upper and lower sides of the base plate  201  to move horizontally along the base plate  201 . 
   A movable block  211  is fixed to the mover  203 , and a variable picker  221  with a cylinder  221   a  and nozzle head unit  221   b  is fixed to the movable block  221 . 
   Moreover, like the transferring apparatus according to the first embodiment of the present invention, a linear scale  231  is coupled with an upper end of the mover  203  to control a displacement of the variable picker  221  and a scanning head  232  is installed on an upper end of the base plate  201  to encode a numerical value of the linear scale  231 . 
   Besides, a plurality of hall sensors (not shown in the drawing) are arranged to leave a predetermined interval from each other on a lower end of the base plate  201 , and a sensing piece (not shown in the drawing) extending toward the hall sensors is coupled with a lower end of the mover  203 . 
   Operation of the above-constituted transferring apparatus according to the second embodiment of the present invention is accomplished more simply than that of the first embodiment of the present invention. And, the above-constituted transferring apparatus according to the second embodiment of the present invention facilitates to transfer two of the semiconductor devices simultaneously. 
   Accordingly, the linear motors are used as means for driving a plurality of pickers, and several pickers are interoperated simultaneously by the least linear motors. 
   Therefore, the present invention enables to simplify the structure of the transferring apparatus as well as reduce its size and weight. 
   Moreover, the use of the linear motor(s) prevents dust from being generated when the pickers are varied in position, reduces noise to facilitate its maintenance, and transfers the picker to the demanded position fast and precisely to improve test efficiency. 
   It will be apparent to those skilled in the art that various modifications and variations can be made in the present invention. 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.