Abstract:
A test apparatus includes one handler connected to a tester and one test board divided into two or more sites or two or more test boards. Since only the sites on the test board (or test boards) need be duplicated, rather than the loading lanes or sorters of the handler, the test apparatus can be conveniently compact. Further, while testing semiconductor devices on one site or one test board, semiconductor devices in another site or on another test board can be sorted according to the test result. This enables the reduction or elimination of tester idle time to optimize the efficiency of the test apparatus.

Description:
FIELD OF THE INVENTION  
         [0001]    The present invention relates to semiconductor device testing, and more particularly to a test apparatus and method involving two test boards that interact with one handler.  
         BACKGROUND OF THE INVENTION  
         [0002]    After all processes are carried out, semiconductor devices are packaged and their functions are electrically tested by means of a tester and handler. The tester, which includes a waveform generator, a current/voltage generator, and a current/voltage-measuring unit, tests the electrical functions of semiconductor devices according to the test program. The handler is a kind of robot that automatically conducts the electrical function test for each semiconductor “device under test” (DUT). The handler is an automated assembly to load/unload the DUTs for testing and to sort the tested DUTs based on the test result. A test station is a place where the tester conducts the electric function test, and a test head is a kind of a gate between the handler and the tester.  
           [0003]    A test flow between a tester and a handler head is described below with reference to FIG. 1.  
           [0004]    Referring to FIG. 1, a signal is transmitted between a handler head  100  and a tester  120  through a communication interface  130 . While chips are moved from the chip tray to the handler head  110 , the tester  120  is in an idle state ({circle over (1)}). When a chip is connected to a socket, the handler head  110  transmits a test-start signal to the tester  120  ({circle over (2)}). The tester  120  tests the electronic function of the chip in response to the test-start signal and transmits a test-end signal to the handler head  110  when the test ends ({circle over (3)}). The handler head  110  sorts the tested chips into good chips and defective chips ({circle over (4)}). At this time, the tester is again in the idle state. A reduction or elimination of the tester idle time is desirable because it would improve the efficiency of the test apparatus.  
           [0005]    One example of a test apparatus that reduces tester idle time is disclosed in Korean Patent Application No. 2000-56000, in which a multi-handler has two test points, two sorting means, and two loading lanes, and a test signal is transmitted in a time-division manner to each of the alternate paths of the multi-handler. A test apparatus according to the above patent includes two handlers, two stations, and two head boards. While one semiconductor device is tested at one handler portion, another semiconductor device is sorted and a new semiconductor device is loaded at another handler portion. Unfortunately, because so many of the handler components are duplicated, the test apparatus of the above patent is still fairly large.  
         SUMMARY OF THE INVENTION  
         [0006]    A test apparatus having a relatively small size and yet reduces test idle time, and its test method, are provided.  
           [0007]    A first embodiment of the present invention provides a test apparatus for testing a plurality of semiconductor devices loaded on one handler connected to a tester. The handler includes a test head that counts cycles of a test-clock signal provided by the tester and responds by alternately generating an odd-number signal and an even-number signal, and a lateral head board divided into a first site and a second site on which the DUTs are loaded. The tester tests the DUTs loaded on the first site in response to the odd-number signal, and the tester tests the DUTS loaded on the second site in response to the even-number signal.  
           [0008]    In a second embodiment, the handler includes a test head that counts cycles of a test-clock signal provided by the tester and responds by alternately generating an odd-number signal and an even-number signal, a first lateral head board on which the DUTs are loaded, and a second lateral head board on which the DUTs are loaded. The tester tests the DUTs loaded on the first head board in response to the odd-number signal, and the tester tests the DUTs loaded on the second head board in response to the even-number signal.  
           [0009]    In a third embodiment, the handler includes a test head on which fuses are selectively shorted by a voltage source to alternately generate a first selection signal and a second selection signal, and a head board divided into first and second sites on which the DUTs are loaded. The tester tests the DUTs loaded on the first site in response to the first selection signal, and the tester tests the DUTs loaded on the second site in response to the second selection signal.  
           [0010]    In a fourth embodiment, the handler includes a test head on which fuses selectively shorted by a voltage source alternately generate a first selection signal and a second selection signal, a first head board on which the DUTs are loaded, and a second head board on which the DUTs are loaded. The DUTs loaded on the first head board are tested in response to the first selection signal, and the tester tests the DUTs loaded on the second head board in response to the second selection signal.  
           [0011]    In a fifth embodiment, the invention provides a method of testing a plurality of semiconductor devices loaded on one handler connected to a tester. The method includes loading the semiconductor devices on two or more sites of the handler&#39;s head board, making the handler transmit a test-require signal to the tester, making the tester receive the test-require signal and query the handler as to whether the semiconductor devices are all loaded on a fullsite, making the handler count cycles of a test clock signal from the tester to generate site selection signals for selecting the site, testing the DUTs loaded on a site in response to the corresponding site selection signal, sorting the tested DUTs according to their test results, and selecting another site in response to the site selection signal.  
           [0012]    In a sixth embodiment, the method includes loading the semiconductor devices on two or more sites of the handler head board, making the handler transmit a test-require signal to the tester, making the tester receive the test-require signal and query the handler whether the semiconductor devices are loaded on a fullsite, making the handler selectively short embedded fuses to a voltage source to generate site selection signals for selecting the sites, testing the DUTs loaded on a site in response to the corresponding site selection signal, and sorting the tested DUTs according to their test results and selecting another site in response to the site selection signal. 
       
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0013]    [0013]FIG. 1 shows a test flow between a conventional test and a handler.  
         [0014]    [0014]FIG. 2 shows a handler according to a first embodiment of the present invention.  
         [0015]    [0015]FIG. 3 shows a handler according to a second embodiment of the present invention.  
         [0016]    [0016]FIG. 4 shows a handler according to a third embodiment of the present invention.  
         [0017]    [0017]FIG. 5 shows a handler according to a fourth embodiment of the present invention.  
         [0018]    [0018]FIG. 6 shows a flowchart of a test method between a tester and a handler according to the present invention.  
     
    
     DESCRIPTION OF THE PREFERRED EMBODIMENT  
       [0019]    A handler according to a first embodiment of the present invention is now described below with reference to FIG. 2.  
         [0020]    Referring to FIG. 2, a handler  200  is connected to a tester to test a plurality of loaded semiconductor devices DUT. The handler  200  includes a test head  210  and a lateral handler head board  220 . The test head  210  has a counter  212  that counts cycles from a test clock signal TCLK provided by the tester and responds by alternately generating an odd-number signal ODD and an even-number signal EVEN. A plurality of DUTs are loaded onto the lateral handler head board  220 , which is divided along its width into: a first site  222  and a second site  224 . The tester tests the DUTs loaded on the first site  222  in response to the odd-number signal ODD, and the tester tests the DUTs loaded on the second site  224  in response to the even-number signal EVEN.  
         [0021]    The present invention achieves the advantage of reducing or eliminating tester idle time because the handler  200  sorts tested DUTs from, or loads new untested DUTS to, one of the sites on the lateral board while the tester tests DUTs on the other site. Thus, when the tester finishes testing DUTs on one site, it can immediately begin testing the newly loaded DUTs on the other site without intervening idle time. Further, since a single handler loading to and sorting from two sites is connected to the tester, the test apparatus can be conveniently compact.  
         [0022]    Although the lateral board  220  is divided into two sites (i.e., the first and second sites  222  and  224 ) in the first embodiment, it may be divided into three sites or more. Therefore, it will be understood that the test head  210  may divide the test clock signal TCLK into three or more distinguishable timing signals.  
         [0023]    A handler according to a second embodiment of the present invention is now described with reference to FIG. 3.  
         [0024]    Referring to FIG. 3, a handler  300  includes a test head  310 , a first test board  320 , and a second test board  330 . The test head  310  is identical with the test head  210  of FIG. 2, with a counter  312  that counts cycles of a test clock signal TCLK from the tester and responds by alternately generating an odd-number signal ODD and an even-number signal EVEN. Unlike the sites  222  and  224  on the same lateral board  220  of FIG. 2, the sites in this second embodiment are on two separate test boards  320  and  330 . A plurality of DUTs are loaded onto each of the test boards  320  and  330 . The first test board  320  tests DUTs in response to the odd-number signal ODD, and the second test board  330  tests semiconductor devices in response to the even-number signal EVEN.  
         [0025]    A handler according to a third embodiment of the present invention is now described with reference to FIG. 4.  
         [0026]    Referring to FIG. 4, a handler  400  includes a test head  410  and a vertical board portion  420 . The test head  410  has a fuse unit  412  which selectively connects internal fuses to a voltage source VCC, generating either a first selection signal FS 1  or a second selection signal FS 2  depending on whether an internal fuse is shorted. Like the lateral handler head board  220  of FIG. 2, the vertical handler head board  420  is divided into a first site  422  and a second site  424 , but the vertical configuration of FIG. 4 allows the location of sites  422  and  424  on opposite surfaces of the handler head board. DUTs loaded on the first site  422  are tested in response to the first selection signal FS 1 , and DUTs loaded on the second site  424  are tested in response to the second selection signal FS 2 .  
         [0027]    Although the vertical board portion  420  is divided into two sites (i.e., the first and second sites  422  and  424 ) in the third embodiment, it may be divided into three sites or more. Therefore, the fuse unit may have a plurality of fuses to generate various selection signals and to selectively test semiconductor devices in a corresponding site.  
         [0028]    A handler according to a fourth embodiment of the present invention is now described with reference to FIG. 5.  
         [0029]    Referring to FIG. 5, a handler  500  includes a test head  510 , a first test board  520 , and a second test board  530 . The test head  510  has a fuse unit  512 . Similar to the test head  410  of FIG. 4, the test head  510  generates a first selection signal FS 1  or a second selection signal FS 2  depending on whether a fuse in the fuse unit  512  is shorted. DUTs loaded on the first test board  520  are tested in response to the first selection signal FS 1 , and DUTs loaded on the second test board  530  are tested in response to the second selection signal FS 2 .  
         [0030]    A test flow between a tester and a handler according to the present invention is now described with reference to FIG. 6.  
         [0031]    Referring to FIG. 6, DUTs are loaded on an A site ( 602 ) and a B site ( 604 ) of a handler. The handler transmits a test require signal SRQ ( 606 ) to a tester. After receiving the test require signal SRQ ( 608 ), the tester queries the handler whether the semiconductor devices in the A site and the B site are all loaded on a fullsite ( 610 ). The handler receives the fullsite query ( 612 ), selects either the A site or the B site ( 614 ), and connects a DUT from the selected site to the tester socket ( 616 ). The DUT state signal is transmitted from the selected site ( 618 ) and received by the tester ( 620 ). The tester tests the DUT ( 622  and  624 ) and treats the test result ( 626 ). The handler receives the test result (BIN) ( 628 ), sorts good devices and bad devices from the selected site and simultaneously selects another site ( 630 ). To test DUTs on the newly selected site, the handler transmits the test require signal SRQ to the tester and the subroutine ( 600 ) is repeated for the new site.  
         [0032]    As explained so far, a test apparatus includes one handler connected to a tester, and either one test board divided into two or more sites, or two or more separate test boards. Since the test apparatus needs only a single loading lane, a single tester, and a single sorter, and only the test boards or test sites need to be multiple, the apparatus may be conveniently compact. Further, the apparatus can test DUTs in one site or on one test board while simultaneously sorting DUTs according to their test results in another site or on another test board. This enhances the efficiency of testing by reducing or eliminating tester idle time.  
         [0033]    While the present invention has been described with reference to its preferred embodiments, various alterations and modifications will occur to those skilled in the art. All such alterations and modifications may be made within the scope and spirit of the appended claims.