Abstract:
Provided is a pushing block for use in a handle and a handler equipped with the pushing block. The pushing block includes pushing pins, provided under the test tray, each pushing the latch upwards from under the test tray to enable the latch to release the packaged chip, a first plate on which the pushing pins are provided, and an assembly changing horizontal motion into vertical motion to move the first plate vertically. Positioning of the pushing block under the test tray prevents interference between the pushing block and the picker during loading and unloading and makes it convenient to take corrective action when malfunction of the picker occurs.

Description:
CROSS REFERENCE TO RELATED APPLICATIONS 
       [0001]    This application claims priority from Korean Patent Application No. 10-2006 l  -0092269, filed on Sep. 22, 2006, the disclosure of which is incorporated herein in its entirety by reference. 
       BACKGROUND OF THE INVENTION 
       [0002]    1. Field of the Invention 
         [0003]    The present invention relates to a pushing block which enables a latch to hold in place or release a packaged chip in a socket of a test tray when loading or unloading the packaged chip upon and from the socket and a handler equipped with the pushing block. 
         [0004]    2. Description of the Background Art 
         [0005]    At the conclusion of a packaging process, a handler puts packaged chips through a series of environmental, electrical, and reliability tests. These tests vary in type and specifications, depending on the customer and use of the packaged devices. The tests may be performed on all of the packages in a lot or on selected samples. 
         [0006]    The handler puts packaged chips into a test tray and supplies the test tray to a tester. The tester includes a test board with a plurality of sockets, performing an electrical test on the packaged chips. The packaged chips are inserted into the sockets of the test board for the electrical test. The handler puts the packaged chips into a test tray, i.e. a jig and inserting the packaged chips contained in a test tray into sockets of the test board. The handler sorts the packaged chips according to test results. The handler removes packaged chips from a user tray and put the removed packaged chips into sockets of the test tray. The handler transfers the test tray to the tester. (This is referred as to “a loading operation”. The handler removes tested packaged chips from the sockets of the test tray and the tested packaged chips to a user tray (This is referred as to “an unloading operation”) 
         [0007]    The handler includes a plurality of pickers picking up and transferring the packaged chips in the loading and unloading operations. The picker, movably provided on a body of the handler, picks up, transfers, and places the packaged chips. 
         [0008]    Sockets, into which the packaged chips are inserted, are arranged in rows and columns in the test tray. Each socket includes a latch holding the packaged chips in place. When the latch releases the packaged chip, the packaged chip may be removed from the socket. 
         [0009]    The conventional picker includes a pushing pin by which the latch is pushed to release the packaged chip. The pushing pin protrudes farther than a nozzle of the picker. This enables the pushing pin to push the latch before the nozzle comes in contact with the packaged chip, when the picker is moved down to insert or pick up the packaged chip into or from the socket. 
         [0010]    In this case, the pushing pin has to be provided to each of the pickers. This increases a size of the picker, and requires the picker to carry the pushing pin with it even when it is not moved down to insert or pick up the packaged chip into or from the socket. 
         [0011]    To solve such a problem, a pushing block is provided which enables the latch to release the packaged chip, as shown in  FIG. 1 . The latch  30 , including a button part  32  and a holding part  34 , is provided to each of sockets of the test tray  20 . The holding part  34  pushes the packaged chip inserted into the socket to hold it in place. The button part  32  is pushed by the pushing pin to enable the latch to release the packaged chip inserted into the socket. 
         [0012]    A rotating bar (not shown) is provided between the holding part  34  and the button part  32 . So, when the pushing pin pushes an upper region of the button part  34 , the holding part  34  is lifted, thus releasing the packaged chip. When the pushing pin withdraws from the button part  32 , the latch returns to its original position by virtue of elastic force of a torsion spring, or a coil spring, thus holding the packaged chip in place. 
         [0013]    When the picker  80  inserts or picks up the packaged chip into or from the socket, the pushing pin releases the latch  30 . When the test tray  20  is in transit, the latch holds the packaged chip in place to prevent it from being loose or deviating or dropping from the socket. 
         [0014]    The pushing pin  42  is provided on the pushing block  10 . As shown in  FIG. 1 , the pushing block  10  includes a pushing plate  40 , on which a plurality of pushing pins is provided, and a cylinder block  60  moving up and down the pushing plate  40 . Pushing pin  42  on the pushing plate  40  is as numerous as the latches on the test tray. 
         [0015]    The pushing plate  40  is moved up and down by the cylinder block  60 . The cylinder block  60  includes a cylinder  62 , a connecting rod  64 , and a piston. The cylinder  62  is fixably provided on a frame  50  extending over an exchanging unit. An end of the connecting rod is connected to the piston and the other to the pushing plate  40 . Reciprocating motion of the piston is changed to up-and-down motion of the pushing plate  40 . 
         [0016]    The frame  50  includes a left frame  50   a  and a right frame  50   b  which are opposite to each other, in one pair. 
         [0017]    The up-and-down motion of the pushing plate  40  enables the pushing pin  42 , which is provided on the pushing plate  40 , to push and release the latch of socket. 
         [0018]    The pushing block  10  is provided over the test tray  20  on an exchanging unit. This makes it difficult to take corrective action when the picker fails to function properly, such as deviation of the packaged chip from the socket, and wrong insertion of the packaged chip into the socket. Furthermore, positioning of the pushing block  10  between the picker and the test tray causes interference between the picker and the pushing block, thus making the packaged chip deviate from the socket. 
         [0019]    The frame  50  has to be as wide as possible to minimize the interference between the picker and the pushing block  10 . The cylinder block  60  is preferably provided only on the frame  50 . This requires increase in a size of the pushing plate  40 , thus increasing the number of the cylinder block  60  and a driving power driving the cylinder blocks  60 . 
         [0020]    When the pushing plate  40  is too broad, the middle of the pushing plate  40  tends to bend. This causes a malfunction of the picker. For example, the pushing pin on the bent region of the pushing plate  40  fails to push the latch properly. As a result, the picker fails to pick up the packaged chip. 
         [0021]    When the pushing plate  40  is too large, a pushing plate guide  70  has to be additionally provided to guide up-and-down motion of the pushing plate  40 . 
       SUMMARY OF THE INVENTION 
       [0022]    Therefore, an object of the present invention is to provide a pushing block functioning properly without interference with a picker and a handler equipped with the pushing block. 
         [0023]    Another object of the present invention is to provide a pushing block having a simplified structure and a handler equipped with the pushing block. 
         [0024]    According to an aspect of the present invention, there is provided a pushing block for use in a handler, including pushing pins, provided under a test tray, each pushing a latch upwards from under the test tray to enable the latch to release a packaged chip, a first plate on which the pushing pins are provided, and an assembly changing horizontal motion into vertical motion to move the first plate vertically. 
         [0025]    The assembly includes a cylinder base fixably provided on a body of the handler, a cylinder block including a cylinder fixably provided on a upper side of the cylinder base, and a connecting rod transferring reciprocal motion of a piston inside the cylinder, a third plate to which motion of the connecting rod is transferred, fourth plates, each having guide holes by which a direction of motion of the third plate is changed, moving rods, provided on lateral sides, moving along the guide holes, a second plate, supporting the first plate, and to which vertical motion of the third plate is transferred, and a cylinder base on which the cylinder block is fixably provided. 
         [0026]    According to another aspect of the present invention, there is provided a handler, a test unit testing packaged chips, a loading stacker where the packaged chips are loaded for testing, an unloading stacker, provided adjacent to the loading stacker, where the tested packaged chips, after sorted, are unloaded, a test tray containing tested or not-tested packaged chips for transferring, an exchanging unit where the packaged chips tested in the test unit are unloaded from the test tray and the not-tested packaged chips are loaded upon the test tray, at least one picker moving between the loading stacker and the exchanging unit, and between the exchanging unit and the unloading stacker, to transfer the tested or not-tested packaged chips, and a pushing block, provided under the exchanging unit, including a first plate on which to provide pushing pins which release the packaged chip from the test tray, and an assembly moving the first plate vertically by changing vertical motion into horizontal motion. 
         [0027]    Positioning of the pushing block under the test tray prevents interference between the pushing block and the picker and makes it convenient to take corrective action when malfunction of the picker occurs. Furthermore, the pushing block is made compact. 
         [0028]    Also, the whole bottom of the first plate is supported and pushed upwards, thus enabling all the pushing pins to open the latches uniformly at the same time. 
         [0029]    The foregoing and other objects, features, aspects and advantages of the present invention will become more apparent from the following detailed description of the present invention when taken in conjunction with the accompanying drawings. 
     
     
       BRIEF DESCRIPTION OF THE DRAWINGS  
         [0030]    The accompanying drawings, which are included to provide a further understanding of the invention and are incorporated in and constitute a part of this specification, illustrate embodiments of the invention and together with the description serve to explain the principles of the invention. 
           [0031]    In the drawings: 
           [0032]      FIG. 1  is a perspective view illustrating a conventional pushing block equipped with a conventional handler; 
           [0033]      FIG. 2  is a perspective exploded view illustrating a pushing block and a test tray which are for use in a handler, according to an embodiment of the present invention and a test tray; 
           [0034]      FIG. 3  is a perspective comprehensive view illustrating the pushing block of  FIG. 2 ; 
           [0035]      FIG. 4  is a view illustrating that a moving rod arrives at an upper stopping hole and stably stays there; 
           [0036]      FIG. 5  is a view illustrating that the moving rod arrives at a lower stopping hole and stably stays there. 
           [0037]      FIG. 6  is a perspective exploded view illustrating an embodiment of a socket according to the present invention; 
           [0038]      FIGS. 7 and 8  are cross-sectional views illustrating how the socket of  FIG. 6  operates; and 
           [0039]      FIG. 9  is a view illustrating a handler equipped with the pushing block according to the present invention. 
       
    
    
     DETAILED DESCRIPTION OF EXEMPLARY EMBODIMENTS 
       [0040]    Reference will now be made in detail to the preferred embodiments of the present invention, examples of which are illustrated in the accompanying drawings. 
         [0041]      FIG. 2  is a perspective exploded view illustrating a pushing block  120  and a test tray which are for use in a handler, according to an embodiment of the present invention and a test tray.  FIG. 3  is a perspective comprehensive view illustrating the pushing block  120  of  FIG. 2 . 
         [0042]    The handler inserts packaged chips into a test tray and transfers the test tray containing the packaged chips to a tester. The handler unloads tested packaged chips from sockets of the test tray. 
         [0043]    As shown in  FIGS. 2 and 3 , the pushing block  120  is provided under the test tray  20 . 
         [0044]    The test tray  20  is a jig which serves to contain the packaged chips E for transfer. A plurality of sockets  110  is provided in rows and columns on the test tray  20 . The socket  110  includes a latch which holds inserted packaged in place. The latch includes a holding part  114  holding the packaged chip, inserted into the socket, in place by pushing the packaged chip E, and a butting part  112  releasing the holding part  114 . 
         [0045]    The holding part  114  is moved as the button part  112  is moved. When the button part  112  is moved up, the holding part  114  is moved up, thus releasing the packaged chips. A rotating rod is provided on one side of the button part  112  and the holding part  114  is provided the other side of the button part  112 . The rotating rod provides an axis about which the latch rotates when the pushing pin  132  moves up the button part  112 . 
         [0046]    The pushing block  120  includes a first plate  130  on which the pushing pin  132  is provided, and an assembly  140  by which the first plate  130  is moved up and down. 
         [0047]    The pushing pins  132  on the first plate  130  may be as numerous as the latches on the test tray. The pushing pin  132  may further include a guide pin  134  guiding motion of the first plate for the pushing pins  132  to push the latches accurately. The guide pin  134  protrudes from the first plate  130  farther than the pushing pin  132 . 
         [0048]    As a result, when the first plate  130  is moved up, the guide pin  134  is inserted into the guide hole before the pushing pin  132  comes in contact with the button part  112  of the latch. Thus, the pushing pin  132  accurately pushes the button part  112  of the latch. 
         [0049]    When the pushing pin  132  moves up the button part  112  of the latch, the holding part  114  is also moved up, thus releasing the packaged chip. At this point, the picker picks up the packaged chip from the socket, or inserts the packaged chip into the empty socket. 
         [0050]    The assembly  140  is provided under the first plate  130 . The assembly  140  includes a second plate  182  supporting and holding the first plate  130 , a third plate  170  moving up and down the second plate  182 , a cylinder block  160  transferring horizontal motion to the third plate  170 , a pair of fourth plates  184  changing horizontal motion of the cylinder block  160  into vertical motion, and a cylinder base  150  on which the fourth plate is fixably provided. 
         [0051]    The cylinder base  150  is fixably provided on the body of the handler. The two fourth plates  184  are provided upright on two edges of the cylinder base  150 , respectively, opposite to each other. The cylinder block  160  is fixably provided on the cylinder base  150  between the two fourth plates  184   
         [0052]    The third plate  170  is provided between the two fourth plates  184 . The third plate  170  is a rectangular frame with the cylinder block  160  inside. The third plate  170  is connected to a piston inside the cylinder  162 , with a connecting rod  164 . 
         [0053]    Reciprocating motion of the piston causes reciprocating motion of the third plate  170 . 
         [0054]    The fourth plate  184  has guide holes  185 , each of which is longitudinal and inclined to a bottom of the fourth plate  184  with a predetermined angle. The horizontal motion of the third plate  170  is changed in the vertical motion of the third plate  170 , using the guide holes  185  formed on the fourth plate  184 . 
         [0055]    Moving rods  175 , which are inserted into the guide holes  185 , are provided on both lateral sides of the third plate  170 . Accordingly, when the reciprocating motion of the piston is transferred to the third plate  170 , the moving rods  175  are moved up along the guide holes  185 . In this way, the motion of the third plate  170  is changed from horizontally to vertically. 
         [0056]    The moving rod  175  may further include a bearing  177 . The bearing  177  facilitates sliding motion of the moving rod  175  along the guide hole  185 . 
         [0057]    The guide hole  185  may further include an upper stopping hole  186  and a lower stopping hole  188 . In this case, the guide hole  185  includes the upper stopping hole  186 , the lower stopping hole  188 , and the inclined longitudinal hole  187  connecting between the upper and lower stopping holes  186  and the  188 . 
         [0058]    The upper and lower stopping holes  186  and  188  serve to stop motion of the moving rod  175  along the guide hole  185 . Furthermore, the upper and lower stopping holes  186  and  188  make motion of the moving rod  175  changed stably and smoothly. 
         [0059]    The upper and lower stopping holes  186  and  188  may be horizontally longitudinal. This makes it possible for the moving rod  175  to slide up along the guide hole  185  in a stable manner. That is, the moving rod  175 , which is supported by the third plate  170 , is slopingly moved up in a stable manner, 
         [0060]    The fourth plate  184  may include a plurality of guide holes  185 . Accordingly, the third plate  170  may include a plurality of moving rods  175 . 
         [0061]    The third plate  170  applies a thrust force against the second plate  182  vertically. 
         [0062]    The second plate  182  supports the first plate  130  in a fixed manner. The second plate  182  may be wider that the first plate  130 . 
         [0063]      FIG. 4  is a view illustrating that the moving rod  175  arrives at the upper stopping hole  186  and stably stays there.  FIG. 5  is a view illustrating that the moving rod  175  arrives at the lower stopping hole  188  and stably stays there. As shown in  FIG. 5 , when the moving rod  175  slides down along the guide hole  185 , a height of the first plate  130  get smaller by a vertical distance between the upper and lower stopping holes  186  and  188 . This makes the pushing pin release the latch, thus closing the latch. In a reverse manner, when the moving rod  175  slides up along the guide hole  185 , the height of the first hole  130  gets larger by the vertical distance between the upper and lower stopping holes  186  and  188 . This makes the pushing pin push the latch, thus opening the latch. 
         [0064]    According to the present invention, there exists no interference between the picker and the pushing block because the pushing block is positioned under the test tray. This prevent a malfunction of the picker 
         [0065]      FIG. 6  is a perspective exploded view illustrating an embodiment of a socket  110  according to the present invention.  FIGS. 7 and 8  are cross-sectional views illustrating how the socket  110  of  FIG. 6  operates. As shown in  FIGS. 6 through 8 , the socket  110  includes a latch having a button part  112  and a holding part  114 , a rotating rod  117  providing an axis about which the latch rotates, and a coil spring  118  returning the latch to its original position. The coil spring  118  makes the holding part  114  push the packaged chip inserted into the socket, when a predetermined amount of force isn&#39;t applied to the button part  112 . 
         [0066]    As shown in  FIG. 6 , the button part  112  and the holding part  114  are connected to the socket  110 , with the rotating rod  117 . The button part  112  and the holding part  114  are rotatable about the axis of the rotating rod  117  with respect to the socket. The coil spring  118  is positioned outside the rotating rod  117 , to return the holding part  114  to its original position. As shown in  FIG. 7 , when the latch remains closed by an elastic force of the coil spring, a groove  119  of the socket isn&#39;t allowed to receive the packaged chip. As shown in  FIG. 8 , when the latch remains opened by a thrust force of pushing pin  132 , the groove  119  of the socket is allowed to receive the packaged chip. When the pushing pin  132  withdraws from the latch, the latch is closed by the elastic force of the coil spring. 
         [0067]    The operating mechanism of the latch having the button part  112  and the holding part  114  according to the present invention is not limited to the structures of the latches shown in  FIGS. 6 through 8 . The button part  112  and the holding part  114  as one body, may be balanced in the middle, so that the button part  112  goes up and the holding part goes down, and vice versa. 
         [0068]      FIG. 9  is a view illustrating a handler  200  equipped with a pushing block according to the present invention. The handler according to an embodiment of the present invention includes a loading stacker  210 , an unloading stacker  220 , a test unit  240 , pickers  250 , and the pushing block provided under an exchanging unit. 
         [0069]    The loading stacker  210  is provided in the front. User trays, each of which contains not-tested packaged chips, are placed on the loading stacker  210 . 
         [0070]    The unloading stacker  220  is provided adjacent to the loading stacker  210 . Tested packaged chips, after sorted according to grades, are contained in their assigned user trays on the unloading stacker  220 . 
         [0071]    The packaged chips in the user tray are contained in a test tray  222 . The test tray  222  containing the packaged chips is transferred to the loading stacker  220 . 
         [0072]    The handler may further include the exchanging unit  230 . The exchanging unit  230  is an area where the not-tested packaged chips are loaded into the test tray, or the tested packaged chips are unloaded from the test tray. The buffer unit  260  is provided between the loading stacker  210  or the unloading stacker  220  and the exchanging unit  230 . The buffer unit  260  temporarily receives the packaged chips transferred by the head assembly. The buffer unit includes a plate. The buffer units  260  may be provided next to both sides of the exchanging unit  230  which is provided in the middle of the main body of the handler. That is, the buffer unit  260  may include a loading buffer unit  260   a  and an unloading buffer unit  260   b . In this case, the exchanging unit  230  is provided between the loading and unloading buffer units  260   a  and  260   b . The buffer unit  260  may include two or more plates movable in an y-axis direction. The picker  250 , as shown in  FIG. 9 , includes a first loading picker  250   a  moving between the loading stacker  210  and loading buffer unit  260   a , a second loading picker  250   b  moving between the loading buffer unit  260   a  and the exchanging unit  230 , a first unloading picker  250   d  moving between the unloading stacker  220  and the unloading buffer unit  260   b , and a second unloading picker  250   c  moving between the exchanging unit  230  and the unloading buffer unit  260   b . The pickers are movably provided to an x-axis gantry  271  and y-axis gantry  272 . The first loading picker  250   a  and the first unloading picker  250   d  may be movable in an x-axis or y-axis direction, and the second loading picker  250   b  and the second unloading picker  250   c  may be movable in the x-axis direction. 
         [0073]    The test unit  240  is provided in the rear. The test unit  240  includes a heating-up chamber where the packaged chips are heated up, a test chamber where the packaged chips are tested, and a cooling-down chamber where the packaged chips are cooled down. The test tray containing the packaged chips goes through the heating-up chamber, the test chamber, and the cooling-down chamber, in the preceding order. 
         [0074]    The pushing block according to the present invention is provided under the exchanging unit. The pushing block is moved up to open the latch of the socket provided on the test tray, in order for the packaged chip to be inserted into or removed from the socket, when the test tray containing the packaged chips waits in the exchanging unit, to load or unload the packaged chip upon or from the test tray. The pushing block is moved down to close the latch of the socket provided to the test tray, in order for the packaged chip to be held in place, while the test tray is transferred to the test unit. The operation and structure of the pushing block is the same as above described. 
         [0075]    As the present invention may be embodied in several forms without departing from the spirit or essential characteristics thereof, it should also be understood that the above-described embodiments are not limited by any of the details of the foregoing description, unless otherwise specified, but rather should be construed broadly within its spirit and scope as defined in the appended claims, and therefore all changes and modifications that fall within the metes and bounds of the claims, or equivalents of such metes and bounds are therefore intended to be embraced by the appended claims.