Abstract:
A method for locating wiring swap in a hi-fix structure of a simultaneous multi-electronic device test system is introduced to screen the complicated wiring state of the hi-fix structure and to pinpoint the wiring swap thereinside as well. The hi-fix structure has at least S socket slots for testing electronic devices which each of the electronic devices has at least R leads. The present method, firstly, is to prepare R test unit sets which each of the test unit set includes S identical lead-off elements. Then, all R test unit sets are tested, in order, on the hi-fix structure and the respective test results are recorded. Finally, by analyzing the test results, the wiring swap inside the hi-fix structure can be accurately located.

Description:
CROSS-REFERENCES TO RELATED APPLICATIONS  
         [0001]    This application claims priority from R.O.C. Patent Application No. 092103954, filed Feb. 25, 2003, the entire disclosure of which is incorporated herein by reference.  
         BACKGROUND OF THE INVENTION  
         [0002]    The invention relates to a method for locating wiring swap in a hi-fix structure of a simultaneous multi-electronic device test system, and more particularly to a rapid and whole-scale test method which utilizes standard sets of test devices to screen and further locate possible wiring swap in the hi-fix structure.  
           [0003]    In the industry of testing electronic devices, one of efficient methods is the one which applies a simultaneous multi-electronic device test system to carry out target testing automatically simultaneously upon batches of electronic devices. Such a simultaneous multi-electronic device test system can be usually seen as a testing dynamic test handler, a memory test system, a silicon-on-chip test system, a liquid crystal display driver test system, a radio frequency integrated circuit test system, or the like.  
           [0004]    In any test system mentioned above, the test system generally has a control unit to operate several test heads, and each test head further includes a hi-fix structure. The hi-fix structure includes a plurality of socket slots arranged typically in an array pattern. Each socket slot is used to receive or mount an electronic device for testing, or a so called device under test (DUT).  
           [0005]    Referring to FIG. 1, a typical test head of a conventional simultaneous multi-electronic device test system is shown. In the test head  1 , a performance board  3 , a hi-fix structure  5  and a plurality of socket slot  51  are constructed in a bottom-to-top layer order. Generally speaking, array patterns for arranging the socket slots  51  on the hi-fix structure  5  vary from manufacturer to manufacturer and also from system to system. As shown in FIG. 2, a top view of a typical array pattern for the socket slots  51  of the hi-fix structure  5  is schematically illustrated. In the N×M array pattern, a total number of N×M socket slots  51 , labeled from TS[1] to TS[NM], are shown. While in testing, N×M electronic devices (not shown in the figure) are automatically and simultaneously transferred onto or removed from the hi-fix structure  5 , in which each electronic device is targeted to a respective socket slot  51 .  
           [0006]    Referring now to FIG. 3, a cross-sectional view along line a-a of FIG. 1 is shown. It is seen that a socket board  50  for receiving leads of electronic device is sandwiched between the socket slot  51  and the hi-fix structure  5 . Also, a number of connecting cables  53  for engaging with respective leads of the electronic device are located to extend from the socket board  50  to the performance board  3 .  
           [0007]    Electric conjunction among the electronic device  10  having P leads, the hi-fix structure  5  and the performance board  3  is schematically shown in FIG. 4. Each connecting cable  53  inside the hi-fix structure  5  is applied to connect electrically a respective one of the leads labeled from L( 1 ) to L(P) and extending from the lead side  101  of the electronic device  10  to a respective predetermined location on the performance board  3 . In FIG. 4, normal or correct wiring of the connecting cables  53  among the electronic devices  10 , the hi-fix structure  5  and the performance board  3  are illustrated by the dashed lines.  
           [0008]    In case that the wiring in the hi-fix structure cannot present a normal state as described in FIG. 4, the testing performed by the test head having the hi-fix structure would be definitely incorrect. Practically, possibility of mis-wiring or, say, wiring swap in the hi-fix structure is not rare, and the existence of such a wiring swap does cause real and not-easy-to-be-detected problems in the application of the simultaneous multi-electronic device test system. Referring now to FIG. 5, a comparison to the FIG. 4 is illustrated to present a typical wiring swap in the hi-fix structure  5 . As shown, cables  53 ′ represented by solid lines (correct wiring by dashed lines also presented for reference purpose) inside the hi-fix structure  5  corresponding to the leads L(k) and L( 1 ) of the electronic device  10  are swapped. It is obvious that the hi-fix structure  5  having the wiring swap in FIG. 5 will lead to inaccurate testing results.  
           [0009]    In some cases, fortunately, the wiring swap in the hi-fix structure can be detected and fixed by the manufacturer during the quality control session, or can be detected during the pilot run in the application field. The wiring swap in the hi-fix structure exists in the simultaneous multi-electronic device test system during its assembly stage in the manufacturer, but an indication of the wiring swap problem usually rises at the moment when a field engineer questions the test results after a substantial period of usage. Under such a situation, the damage caused by the test system having the wiring swap problem may already be significant.  
           [0010]    In the art, in case that a wiring swap is encountered, substantial time and labor are usually required for locating and further correcting the swapped cables. Generally, to avoid time wasted for the shipment between the user end and the manufacturer, the maintenance is usually carried out in the application field, i.e., at the user end. The maintenance targeted to a possible wiring swap includes shutting-down of the test system, disassembling of the test head as well as the hi-fix structure, the connection testing cable by cable, re-assembling, and a final test run to examine if there is another wiring swap. Notably, the maintenance described above is inefficient.  
           [0011]    Empirically, wiring swap in the hi-fix structure usually cannot be resolved in a routine or standard maintenance. The reason is that various cables exist in a limited space inside the hi-fix structure, which significantly complicates the pinpointing of all swapped cables. For example, in a hi-fix structure with N×M socket slots, the number of connecting cables inside the hi-fix structure would be N×M×P if each socket slot is designed to receive an electronic device with P leads. Therefore, verification upon each connecting cables is a tedious and labor-intensive task.  
         BRIEF SUMMARY OF THE INVENTION  
         [0012]    Embodiments of the present invention are directed to a method for locating wiring swap in a hi-fix structure of a simultaneous multi-electronic device test system which can screen at a full scale and rapidly the complicated wiring status inside the hi-fix structure.  
           [0013]    The method for locating wiring swap in a hi-fix structure of a simultaneous multi-electronic device test system is used to investigate the wiring status inside the hi-fix structure and thereby to further pinpoint all the wiring swap thereof. Typically, the hi-fix structure can include at least S socket slots, and each of the socket slots is used to receive an electronic device with at least R leads. According to one aspect of the invention, the method of the present invention comprises following steps.  
           [0014]    (1) Prepare R test unit sets. Each of the test unit sets can have S identical lead-off devices. The lead-off device is prepared by cutting a specific lead of the same electronic devices. In addition, every lead-off devices in the same test unit set is designed to have the same lead cut off; i.e., the lead at the same location with respect to the electronic device. Further, any two electronic devices from different test unit sets have different cut-off leads, though the electronic devices are preferable the same.  
           [0015]    (2) Mount one of the test unit sets onto the hi-fix structure, by one lead-off device onto a respective socket slot, and then process a predetermined test therewith.  
           [0016]    (3) Record test results from the predetermined test.  
           [0017]    (4) Determine whether or not all of the test unit sets have been tested with the predetermined test; in case that all of the test unit sets have been tested, process step (5); otherwise, remove the test unit set from the hi-fix structure and process steps (2) to (4) with another test unit set.  
           [0018]    (5) Analyze all the test results obtained by step (4) and determine the wiring swap in the hi-fix structure.  
           [0019]    In one embodiment of the present invention, the test unit set applied to the method for locating wiring swap in a hi-fix structure of a simultaneous multi-electronic device test system can be decided by following steps.  
           [0020]    (1a) Prepare S standard test sets. Each of the standard test sets can have at least R lead-off devices, and every lead-off device in the same standard test set has a different lead cut off, i.e., different cut-off lead.  
           [0021]    (1b) Sort or collect the lead-off devices with the same cut-off leads from the standard test units to form R test unit sets, in which each test unit set includes the same lead-off devices.  
           [0022]    In some embodiments of the present invention, the test unit set for locating wiring swap in a hi-fix structure of a simultaneous multi-electronic device test system can comprise a plurality of identical lead-off devices, in which the lead-off device is a predetermined electronic device having a plurality of leads and having a specific lead to be cut off.  
           [0023]    In one embodiment of the test unit set according to the present invention, the lead-off device can further include a set mark for distinguished the lead-off devices of the other test unit sets. Preferably, the order or number of the cut-off lead can be used as part of the set mark to label the lead-off device of the respective test unit set.  
           [0024]    In specific embodiments of the present invention, the standard test set used as a source to form the test unit set can comprise a plurality of different lead-off devices. Each of the lead-off devices has a plurality of leads and has a respective lead to be cut off (i.e., the cut-off lead). Every two of the lead-off devices in the standard test set differ from each other in orders or locations of the cut-off leads.  
           [0025]    In one embodiment of the standard test set according to the present invention, the lead-off device can further include a lead-off mark for indicating the location of the cut-off lead. In another embodiment of the standard test set according to the present invention, the lead-off device can further include a set mark for labeling the current standard test set.  
           [0026]    In one embodiment, a test kit comprises a plurality of test unit sets each having a plurality of identical lead-off devices, wherein the lead-off devices in each test unit set have identical cut-off leads which are different from the cut-off leads of other test unit sets. In another embodiment, a standard test set kit comprises a plurality of standard test sets each having a plurality of different lead-off devices, wherein each standard test set includes the same plurality of different lead-off devices. 
       
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0027]    [0027]FIG. 1 is a perspective view of a conventional test head of a simultaneous multi-electronic device test system;  
         [0028]    [0028]FIG. 2 is a top view of the hi-fix structure of FIG. 1;  
         [0029]    [0029]FIG. 3 is a cross-sectional view along line a-a of FIG. 1;  
         [0030]    [0030]FIG. 4 is a schematic view showing correct wiring of the socket slots in the hi-fix structure;  
         [0031]    [0031]FIG. 5 is a schematic view showing a wiring swap state in wiring of the socket slots in the hi-fix structure;  
         [0032]    [0032]FIG. 6 is a flowchart of a preferred embodiment of the method for locating wiring swap in a hi-fix structure of a simultaneous multi-electronic device test system in accordance with the present invention;  
         [0033]    [0033]FIG. 7 is a schematic view showing a preferred embodiment of the k-th set of the test unit sets applied to the method for locating wiring swap in a hi-fix structure of a simultaneous multi-electronic device test system in accordance with the present invention;  
         [0034]    [0034]FIG. 8 is a schematic view showing a preferred embodiment of the q-th set of the standard test sets applied to the method for locating wiring swap in a hi-fix structure of a simultaneous multi-electronic device test system in accordance with the present invention; and  
         [0035]    [0035]FIG. 9 is a preferred flowchart of step  100  of FIG. 6. 
     
    
     DETAILED DESCRIPTION OF THE INVENTION  
       [0036]    Embodiments of the present invention are directed to a method for locating wiring swap in a hi-fix structure of a simultaneous multi-electronic device test system. In the following description, numerous details are set forth in order to provide a thorough understanding of the present invention. It will be appreciated by one skilled in the art that variations of these specific details are possible while still achieving the results of the present invention. In other instance, well-known components are not described in detail in order not to unnecessarily obscure the present invention.  
         [0037]    As the prior art described above, it is a labor-intensive and time-consuming job to examine possible wiring swap in the hi-fix structure of the simultaneous multi-electronic device test system. Therefore, the locating method of the present invention utilizes existing automatic testing facilities and sets of sample electronic devices with predetermined cut-off leads to carry out full-scale screening test over the hi-fix structure of test head of the facilities. After obtaining the test results, a specific comparison can then be used to locate all the wiring swap thereof.  
         [0038]    The hi-fix structure of concern can include at least S socket slots; in particular, S≦N×M in the typical hi-fix structure  5  of FIG. 2. Each of the socket slots is used to receive and test an electronic device with at least R leads; in particular, R≦P in the typical electronic device  10  shown in FIG. 4 or FIG. 5.  
         [0039]    Referring now to FIG. 6, a flowchart of the method for locating wiring swap in a hi-fix structure of a multi-electronic device test system in accordance with an exemplary embodiment of the present invention is shown. The method comprises the following steps.  
         [0040]    Step  100 : Prepare R test unit sets. Each of the test unit sets can have S identical lead-off devices. The lead-off device is prepared by cutting a specific lead of a predetermined electronic device. In addition, every lead-off device in the same test unit set is designed to have the same lead cut off; i.e., the cut-off lead is at the same location with respect to the electronic device. Further, any two electronic devices from different test unit sets can have different cut-off leads, though the electronic devices are still the same.  
         [0041]    Step  200 : Mount one of the test unit sets onto the hi-fix structure, by having the lead-off device plugging into a respective socket slot, and then process a predetermined test with the test system having the hi-fix structure.  
         [0042]    Step  300 : Record test results from the predetermined test.  
         [0043]    Step  400 : Determine whether or not all of the test unit sets have been tested with the predetermined test. In case that all of the test unit sets have been tested, go to the following step, i.e., step  500 . Otherwise, remove the test unit set from the hi-fix structure (Step  700 ) and then go back to process steps  200  to  400  with another test unit set, till all the test unit sets have been tested over the hi-fix structure.  
         [0044]    Step  500 : Analyze all the test results obtained in step  300  and then determine the wiring swap in the hi-fix structure.  
         [0045]    Step  600 : Record all the wiring swap at the hi-fix structure for further maintenance.  
         [0046]    In the present invention, the lead-off device for testing is obtained by cutting a specific lead of a predetermined electronic device whose performance is well known. Therefore, the test results upon testing the lead-off devices can be easily used to identify the swapping cables in the hi-fix structure. The judgment of determining the swapping cables by evaluating the test results from testing the given lead-off devices is known to those skilled in the art. Therefore, details will be omitted herein.  
         [0047]    In particular, for a hi-fix structure with N×M (≧S) socket slots and each socket slot being used to receive an electronic device with up to P (≧R) leads, the embodiment of the present method of FIG. 6 can still prevail. Nevertheless, in a conservative point of view, full-scale testing upon the hi-fix structure is preferable; i.e., the testing having S=N×M and R=P in FIG. 6.  
         [0048]    Referring now to FIG. 7, a typical test unit set  9  in accordance with the present invention is shown. In the test unit set  9 , a plurality (at least S) of identical lead-off devices  71  are included and each of the lead-off devices  71  has the same cut-off lead  711 , i.e., the L(k) lead.  
         [0049]    As shown in FIG. 7, the lead-off device  71  in the test unit set  9  according to the present invention can further include a set mark  713  for indicating the current test unit set; i.e., TU(k) in this typical set  9 . The TU(k) set mark  713  can be definitely used to label the cut-off lead  711 .  
         [0050]    In the present invention, the preparation of the test unit set  9  can be done by performing a collection from a plurality of identical standard test sets. Referring now to FIG. 8, the standard test set  7  can include a plurality (P as shown) of lead-off devices  71 . The lead-off devices  71  are identical but have respective leads to be cut off (i.e., different cut-off leads  711 , L( 1 ), L( 2 ), . . . , L(k), . . . , L( 1 ), . . . , and L(P) as shown).  
         [0051]    As shown in FIG. 8, the lead-off device  71  of the standard test set  7  can have a lead-off mark  712  for labeling the respective cut-off lead  711 ; L( 1 ), L( 2 ), . . . , L(k), . . . , L( 1 ), . . . , or L(P) as shown. Similarly, the lead-off device  71  of the standard test set  7  can have a set mark  713  (TS(q) as shown) to label the current set number of the standard test set  7 .  
         [0052]    In the present invention, compared to the test unit set  9  described above, all of the standard test sets  7  are the same to have all types of lead-off devices; i.e., from L( 1 ) to L(P) for example. Therefore, the standard test sets  7  can be convenient to be used for preparing any combination of the test unit sets  9 .  
         [0053]    Referring now to FIG. 9, the preparation of the test unit sets  9  (Step  100  of FIG. 6) from sorting the standard test sets  7  can have the following steps.  
         [0054]    Step  101 : Prepare S standard test sets. Each of the standard test sets can have at least R lead-off devices, and every lead-off device in the same standard test set has a different lead cut off; i.e., different cut-off lead.  
         [0055]    Step  103 : Sort or collect the lead-off devices with the same cut-off leads from the standard test units to form R test unit sets, in which each test unit set includes the same lead-off devices.  
         [0056]    In the present invention as described above, a useful result of every testing upon the hi-fix structure with the test unit set can be obtained because of the cut-off leads and the predetermined electronic devices. Furthermore, the preferred method shown in FIG. 6 which screens all cables in the hi-fix structure related to all the R leads is a conservative examination. In particular, in case that an electronic device to be tested has part of leads totally non-related in function and connection to other leads (usually seen in a multi-chip module), the lead-off device of the test unit set or the standard test set can then have more than one lead to be cut. Significantly, those leads to be cut in the same electronic devices should be independent of each other in function and connection. Upon such an arrangement, the comparison and judgment to determine the wiring swap through the results obtained by the present invention can still prevail, and also the number of the lead-off devices needed for testing of the present invention can be reduced.  
         [0057]    In the present invention, timings for performing the locating method of the present invention can be the arrival time of the test system, the time of periodical maintenance upon the test system, or any time that needs an extra survey upon the connection cables in the hi-fix structure.  
         [0058]    By providing the method for locating wiring swap in a hi-fix structure of a simultaneous multi-electronic device test system described above, the status of connection cables inside the hi-fix structure can be rapidly and full-scale investigated. Therefore, the labor for maintenance and shutdown time of the test system can be greatly saved.  
         [0059]    While the present invention has been particularly shown and described with reference to a preferred embodiment, it will be understood by those skilled in the art that various changes in form and detail may be without departing from the spirit and scope of the present invention.