Abstract:
A test handler apparatus, having a treatment area; a testing station in the treatment area; and an output unit connected to an output of the treatment area. An input unit picks singulated or stripped packages and unloads them on carrier boats in a loading zone; a conveyor mechanism transfers the carrier boats from the loading zone through the treatment area to the testing station and from the testing station to the output unit. In practice, the carrier boat forms a universal carrier which is able to contain multiple singulated or strip packages for the purpose of testing. Placing packages onto carriers with standardized dimension allows handler equipment to accommodate the packages in singulated or strip condition.

Description:
BACKGROUND OF THE INVENTION  
         [0001]    1. Field of the Invention  
           [0002]    The present invention relates to a test handler apparatus for SMD (surface mount devices), BGA (ball grid arrays) and CSP (chip scale packages).  
           [0003]    2. Description of the Related Art  
           [0004]    As known, a wide variety of packages has been developed for integrated circuit application. These packages are used in surface mount devices (SMD), Ball Grid Arrays (BGA) and chip scale packages (CSP). After these packages have been fabricated or sealed, their parameters need to be compared to both the technical specification and the customer requirements. Commercially available testing systems can be categorized as a standalone or automated handling system with limited flexibility and capacity.  
           [0005]    Critical issues of testing include how to increase productivity, how to avoid lead/ball damage, how to cope with operational and maintenance consequences as a result of package changes.  
           [0006]    A prior art testing includes steps of input transfer, hot/ambient chamber treating, package transportation, testing and output transfer. Input transfer involves loading from stacked trays when operated as standalone or direct loading from the previous operation when connected in an inline system.  
         BRIEF SUMMARY OF THE INVENTION  
         [0007]    One embodiment of the invention improves the throughput of the handling equipment with multiple matrix units testing, either for singulated or strip packages of the embodiment eliminates changing tester load board/test contacts block.  
           [0008]    According to an embodiment of the invention, package handling improvement is achieved by modifying the holding mechanism design. In particular, according to one aspect of the invention, a universal carrier is provided which is able to contain multiple singulated or strip packages for the purpose of testing.  
           [0009]    Placing packages onto carriers with standardized dimensions allows handler equipment to accommodate the packages in singulated or strip condition. The handler equipment would deliver them to the tester for testing.  
           [0010]    According to an embodiment of the invention, the test handler apparatus for testing SMD, BGA and CSP packages comprises the following elements:  
           [0011]    An input transfer means;  
           [0012]    A hot/ambient chamber;  
           [0013]    A carrier transportation means;  
           [0014]    A universal carrier mechanism;  
           [0015]    A universal matrix test-site contact assembly;  
           [0016]    A ganged matrix singulated testing;  
           [0017]    A matrix strip package testing  
           [0018]    An output transfer means. 
       
    
    
     BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWING(S)  
       [0019]    For the understanding of the present invention, a preferred embodiment is now described, purely as a non-limitative example, with reference to the enclosed drawings, wherein:  
         [0020]    [0020]FIG. 1 shows a plan view from above of a handing apparatus according to the invention;  
         [0021]    [0021]FIG. 2 is a perspective view of the handling apparatus of FIG. 1;  
         [0022]    [0022]FIG. 3 a  is a perspective view of a package input transfer unit;  
         [0023]    [0023]FIGS. 3 b  and  3   c  show cross-sections of the package input transfer unit of FIG. 3 a , for singulated and stripped packages, respectively;  
         [0024]    [0024]FIGS. 4 a  and  4   b  are perspective views of a package carrier loaded with a formed strip and singulated packages, respectively:  
         [0025]    [0025]FIGS. 5 a ,  5   b ,  5   c  show different layouts of the package carrier of FIGS. 4 a ,  4   b ; and  
         [0026]    [0026]FIG. 6 shows a cross-section of a tester head; and  
         [0027]    [0027]FIG. 7 is a plan view of the testing station. 
     
    
     DETAILED DESCRIPTION OF THE INVENTION  
       [0028]    With reference to FIGS. 1, 2, a test handler apparatus  1  comprises an input unit  2 ; a hot/ambient chamber  3 ; a loading zone  4 ; carrier boat transfer mechanisms  20 ,  6 ,  47 ; a testing station  5 ; a test head  7  in the testing station  5 ; a singulation station  8 ; and an output unit  9 .  
         [0029]    In detail, the input unit  2  picks up a gang of matrix singulated packages  30  (FIG. 3 b ) or a strip of packages (FIG. 3 c ), processed by the previous operation. The invention can be designed to handle different quantities of packages  30 .  
         [0030]    The structure of the input unit  2  is shown in FIG. 3 a  and comprises a slide  10  movable along a horizontal path and carrying a vertically slidable transfer arm  11 . The transfer arm  11  picks up the packages  30  (either in a strip or singulated) from a previous package manufacturing unit (not shown) and holds them by means of a vacuum system with individual sensors to detect the presence of package  30  during the transfer. Details of the input unit  2  gripping singulated packages  30  and stripped packages  30  are shown in FIGS. 3 b  and  3   c , respectively. The packages  30  are placed onto carrier boats  12  in the loading zone  4 , near the hot/ambient chamber  3 . The singulated packages  30  of a frame are all taken together, with the same pitch as in a strip and then deposited in the same arrangement onto one carrier boat  12 .  
         [0031]    The carrier boats  12  (see FIGS. 4 a ,  4   b ) comprise a plurality of seats  15  (better shown in the cross section of FIG. 6), one for each package  30 , and cavities  16  for the pins. The seats are arranged in a matrix arrangement, with rows extending transversely to the feeding direction in the testing station  5 . Furthermore, each carrier boat  12  comprises a plurality of test head locating holes  17  extending on a side of the carrier boats  12  at constant pitch, and strip clampers  18 , for holding a strip in the desired position. The carrier boats  12  also include lead frame location pins (not shown) for correctly locating a strip, and holes in the bottom (not shown), to allow gripping by a gripper of the carrier boat transfer mechanisms. The test head locating holes  17  are aligned on a line in the feeding direction in the testing station  5 ; alternatively they are provided on both sides of the carrier boats  12 . Generally, one test head locating hole  17  is provided for two rows of seats  15  (two rows of packages  30 ), so that two rows of packages  30  are tested simultaneously.  
         [0032]    The shape, position and number of the seats  15  and the cavities  16  depend on the specific packages  30  and frames the carrier boats  12  are intended for, and are the same for strip packages and singulated packages  30  of the same type, as visible from FIGS. 4 a ,  4   b.    
         [0033]    Exemplary layouts of the seats  15  in each carrier boat  12  for different-configuration packages  30  and/or frames are shown in FIGS. 5 a - 5   c . In FIG. 5 a , X is the pitch between two units along the x-axis, and may range from 3 mm to 450 mm; Y is the pitch between two units along the y-axis, and may range from 3 mm to 110 mm. The number of rows (in the x-axis direction) and columns (in the y-axis direction) may range from 1 to 50.  
         [0034]    In FIG. 5 b , the seats  15  are arranged in islands of two rows and four columns. A is the pitch between two islands along the x-axis and may range from 6 mm to 450 mm; B is the pitch between two islands along the y-axis and may range from 6 mm to 110 mm. The number of islands (in the x-axis and y-axis direction) may range from 1 to 50.  
         [0035]    In FIG. 5 c  single islands are aligned in the x-axis; each island comprises a minimum of two seats in the x- or y-axis direction, wherein A has the same meaning and values indicated for FIG. 5 b.    
         [0036]    Referring again to FIGS. 1, 2, the carrier boats  12 , after loading with the singulated packages  30  or entire strips by the input unit  2 , are advanced within the hot/ambient chamber  3  along the direction of the arrow  20  by means of a first carrier boat transfer mechanism of any known structure, for example comprising a gripper engaging bottom holes in the carrier boats  12 , and brought to a hot plate unit  25 . Here, if testing so requires, the underside of an overlying carrier boat  12  is heated by a heating means to a predetermined temperature. Inside the hot/ambient chamber  3 , the packages  30  on the carrier boat  12  are held for a certain time period, preferably two minutes. In the alternative, if testing does not require heating of the packages  30 , carrier boats  12  are held in ambient environment.  
         [0037]    Thereafter, a carrier boat  12  is transferred onto an input adapter  26  including a first lifter  26   a  and a gripper  26   b  (FIG. 7) engaging the carrier boats  12  from below.  
         [0038]    The input adapter  26  feeds each carrier boat  12  to a second carrier boat transfer mechanism  6 , including a pair of jaws  27   a ,  27   b  arranged each on a respective side of the transportation path. As shown in FIG. 7 (showing the jaws  27   a ,  27   b  with continuous line in the rest position and the jaw  27   a  with dotted line in the 0 position at the end of testing), the jaws  27   a ,  27   b  operate alternatively to grip each one carrier boat  12  and index it below the test head  7 . The jaws  27   a ,  27   b  advance each carrier boat  12  of a step corresponding to the pitch of the test head locating holes  17  to allow testing of a group of packages  30  associated with a test head locating hole  17 .  
         [0039]    Specifically, with reference to FIG. 7, a first of the two jaws, for example jaw  27   a , moves toward a facing carrier boat  12 , grips it and advances it under the test head  7  to bring a first group of packages  30  in the test position. After testing of the first group (as below explained), the first jaw  27   a  advances the carrier boat  12  of a step and so on until the last group of packages  30  has been tested (dotted position). Then, simultaneously, the first jaw  27   a  moves away from the tested carrier boat  12  while the second jaws  27   b  moves toward a subsequent carrier boat  12  (brought to the gripping position by the input adapter  26 ) and grips it. During the advancement of the second jaw  27   b , the first jaw  27   a  returns in the rest position, ready for gripping a further carrier boat  12 , at the end of testing of the carrier boat  12  gripped by the second jaw  27   b.    
         [0040]    After each advancement of a carrier boat  12  in the testing station  5 , a second lifter  28  having a platform  29  lifts the carrier boat  12  to the test head  7 . The test head  7  is located stationary above the transportation track. To increase precision in positioning the carrier boat  12  to be tested, conical pins (not shown) are provided below the test head  7  for engaging the test head locating holes  17 . Along the transportation track in the testing station  27 , the packages  30  are held against the respective carrier boat  12  by vacuum, as shown in FIG. 6 by arrows  45 .  
         [0041]    After a carrier boat  12  is docked, a group of packages  30  is tested electrically, as shown in FIG. 6, in accordance with the test specification required in particular, testing of packages  30  is made via test fingers or pins  32  mounted on a tester head contact block  31  belonging to the test head  7  and in contact with the top surface of the formed leads extending from the package  30  to the end of leads (lead shoulders). The testing fingers or pins  32  can be single or Kelvin contacts.  
         [0042]    The test result will be communicated to the handling equipment, in a per se known manner, and its status is stored in a memory. Upon completion of testing of a group of packages  30 , the carrier boat  12  is moved down by the second lifter  28  and indexed one pitch by the respective jaw  27   a ,  27   b  to present the next group of packages  30  for testing. To ensure detaching of the packages  30  from the tester head contact block  31  and in particular from the test fingers or pins  32 , the tester head contact block  31  comprises a plurality of a stripper pins  33 , one for each package  30  just tested; that maintain the packages  30  against the respective carrier boat  12  and avoid any sticking.  
         [0043]    Then, the second lifter  28  moves the carrier boat  12  upwards to put another group of the packages  30  in contact with the contact fingers or pins  32  to do the testing. This process repeats until all the packages  30  are tested.  
         [0044]    A gripper  47  engages carrier boats  12  that have completed testing and takes them to the output of hot/ambient chamber  3 . Outside the hot/ambient chamber  3 , the singulation station  8  singulates the strip packages, but is, inactive in case of already singulated packages  30 .  
         [0045]    Then, as shown in FIG. 2 (wherein the singulating station  8  has been omitted for clarity), at the output unit  9 , including an output adapter  34  and a miniturret  35 , packages  30  are removed from the carrier boats  12  and sorted through by the miniturret  35 ; rejected packages  30  are brought to rejects bins  36  (FIG. 1) good packages  30  are loaded onto output shuttles  37  that move them to the next operation, and empty carrier boats  12  are circulated, through a belt conveyor  38  and a third lifter  40 , to the loading zone  4 , for loading further packages  30 , in singulated or strip condition, as shown by arrows  41 .  
         [0046]    Some advantages of the test handier apparatus  1  are the following. The test handler apparatus is of universal application and may treat any type of packages, either singulated or stripped, by virtue of the use of carrier boats adapted to the type and configuration packages. Thus, for treating different type packages,  5  it is only necessary to provide carrier boats  12  with the specific seats and cavities layout.  
         [0047]    The matrix-like arrangement of the seats  15  and its arrangement according to the specific frame of the packages allows the same carrier boats  12  to be used for singulated and stripped packages with a same shape and frame arrangement.  
         [0048]    Transfer of the packages  30  is made automatically from the input unit through the entire test handler independently from the singulated and stripped configuration.  
         [0049]    The apparatus is able to test packages in parallel using a universal matrix contact test site.  
         [0050]    The packages are precisely indexed and positioned at the test head by means of the test head locating holes  17 ; furthermore the packages are held in position through vacuum suction and surely released after testing by virtue of the stripper pins.  
         [0051]    Finally, it is clear that numerous variations and modifications may be made to the apparatus and method described and illustrated herein, all falling within the scope of the invention as defined in the attached claims.  
         [0052]    All of the above U.S. patents, U.S. patent application publications, U.S. patent applications, foreign patents, foreign patent applications and non-patent publications referred to in this specification and/or listed in the Application Data Sheetare incorporated herein by reference, in their entirety.