Abstract:
The present invention relates to a substrate and testing method thereof. The method of the invention comprises: (a) providing a substrate, the substrate having a first surface and a second surface, the first surface having a plurality of first testing pads and the second surface having a plurality of second testing pads; (b) forming a conductive material on the first surface to electrically connect at least two first testing pads; and (c) testing the substrate by utilizing a testing fixture, the testing fixture having at least one first testing probe unit and at least one second testing probe unit. Whereby, the first testing probe unit and the second testing probe unit can easily measure the electrical characteristics of the substrate, and the testing process and testing time can be reduced.

Description:
BACKGROUND OF THE INVENTION  
       [0001]     1. Field of the Invention  
         [0002]     The invention relates to a substrate and a testing method thereof, particularly to a substrate of electrically connecting testing pads and a testing method thereof.  
         [0003]     2. Description of the Related Art  
         [0004]      FIG. 1  shows a conventional testing method for a substrate. Firstly, a substrate  10  is provided. The substrate  10  has a first surface  101  and a second surface  102 . The first surface  101  is a chip side for attaching a chip, and the second surface  102  is a solder ball side. The first surface  101  has a plurality of first testing pads  103  and the second surface  102  has a plurality of second testing pads  104 . The size of the first testing pad  103  is usually smaller than that of the second testing pad  104 . The first testing pads  103  electrically connect to the second testing pads  104  to form a plurality of circuits  105 . A testing fixture  11  is used for testing the substrate  10 . The testing fixture  11  has a first testing probe unit  12  and a plurality of second testing probe unit  13 . The first testing probe unit  12  has two first testing probes  121 ,  122 , and each second testing probe unit  13  has two second testing probes  131 ,  132 . The first testing probe unit  12  electrically connects to the first testing pad  103 , and each second testing probe unit  13  electrically connects to the second testing pad  104 .  
         [0005]     In the conventional testing method, the first testing pads  103  must be tested one by one, and the first testing probes  121 ,  122  must contact with the same first testing pad  103 . However, the size of the first testing pad  103  is very small, especially for four-wire test probe, so that it is difficult to dispose the first testing probes  121 ,  122  on the same first testing pad  103 . Therefore, some of the first testing pads  103  may be missed for testing, and it will takes very long time to test the substrate  10 .  
         [0006]     Consequently, there is an existing need for providing a substrate and a testing method thereof to solve the above-mentioned problems.  
       SUMMARY OF THE INVENTION  
       [0007]     One objective of the present invention is to provide a testing method for a substrate. The testing method comprises the steps of: (a) providing a substrate, the substrate having a first surface and a second surface, the first surface having a plurality of first testing pads and the second surface having a plurality of second testing pads; (b) forming a first conductive material on the first surface to electrically connect at least two first testing pads; and (c) testing the substrate by utilizing a testing fixture, the testing fixture having at least one first testing probe unit and at least one second testing probe unit.  
         [0008]     Another objective of the present invention is to provide a substrate. The substrate comprises a first surface, a second surface and a first conductive material. The first surface has a plurality of first testing pads. The second surface has a plurality of second testing pads. The first testing pads electrically connect to the second testing pads to form a plurality of circuits. The first conductive material is formed on the first surface and electrically connects at least two first testing pads.  
         [0009]     The testing method and the substrate of the present invention utilize the first conductive material to electrically connect the first testing pads on the first surface, so that the first testing probe unit and the second testing probe unit can easily measure the electrical characteristics of the substrate. Therefore, the testing process and testing time can be reduced, and whether the substrate is good or not can be easily recognized. 
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0010]      FIG. 1  shows a conventional testing method for a substrate;  
         [0011]     FIGS.  2  to  4  show a testing method for a substrate according to a first embodiment of the present invention;  
         [0012]      FIG. 5  shows a testing method for a substrate according to a second embodiment of the present invention;  
         [0013]      FIG. 6  shows a substrate according to a first embodiment of the present invention;  
         [0014]      FIG. 7A  shows a side view of a substrate according to a second embodiment of the present invention;  
         [0015]      FIG. 7B  shows a top view of the substrate according to the second embodiment of the present invention; and  
         [0016]      FIG. 8  shows a substrate according to a third embodiment of the present invention. 
     
    
     DETAILED DESCRIPTION OF THE INVENTION  
       [0017]     FIGS.  2  to  4  show a testing method for a substrate according to a first embodiment of the present invention. Referring to  FIG. 2 , firstly, a substrate  20  is provided. The substrate  20  has a first surface  201  and a second surface  202 . In the embodiment, for example, the first surface  201  is a chip side for attaching a chip, and the second surface  202  is a solder ball side. The first surface  201  has a plurality of first testing pads  203  and the second surface  202  has a plurality of second testing pads  204 . The size of the first testing pad  203  for attaching chip is usually smaller than that of the second testing pad  204 . The first testing pads  203  electrically connect to the second testing pads  204  to form a plurality of circuits  205 . Referring to  FIG. 3 , a first conductive material  21  is used for connecting two of the first testing pads  203  on the first surface  201 . The first conductive material  21  is line-shaped and electrically connects at least two first testing pads  203 .  
         [0018]     Referring to  FIG. 4A , a testing fixture  22  is used for testing the substrate  20 . The testing fixture  22  comprises at least one first testing probe unit  23  and at least one second testing probe unit  24 . In the embodiment, the first testing probe unit  23  has two first testing probes  231 ,  232 , and the second testing probe unit  24  has two second testing probes  241 ,  242 . The first testing probe unit  23  electrically connects the first testing pad  203  and the second testing probe unit  24  electrically connect to the second testing pads  204  so as to measure the electrical characteristics of the substrate  20 . In the embodiment, the distance between the first testing probes  231 ,  232  must be adjusted according to the distance between two of the first testing pads  203 .  
         [0019]     The testing method according to the first embodiment utilizes the first conductive material  21  to electrically connect the first testing pads  203  on  15  the first surface  201 , so that the first testing probes  231 ,  232  of the first testing probe unit  23  can easily electrically connect to the first testing pads  203 . Also, the electrical characteristics of the substrate  20  can be easily measured, the testing process and testing time can be reduced, and that the substrate  20  is good or not can be easily recognized. It should be noted that in other embodiment a second conductive material may be formed on the second surface  202 , and electrically connect at least two second testing pads  204  on the second surface  202 .  
         [0020]     In addition, referring to  FIG. 4B , the testing fixture may comprise a first testing probe unit  25  and a plurality of second testing probe units  26 . In the embodiment, the first testing probe unit  25  has two first testing probes  251 ,  252 , and each second testing probe unit  26  has two second testing probes  261 ,  262 . By utilizing the first testing probe unit  25  and the second testing probe units  26  to electrically connect to the first testing pads  203  and the second testing pads  204  respectively, the electrical characteristics of the substrate  20  can be easily measured, the testing process and testing time can be reduced, and that the substrate  20  is good or not can be easily recognized.  
         [0021]      FIG. 5A  shows a testing method for a substrate according to a second embodiment of the present invention. The difference between the testing method of the first embodiment and the testing method of the second embodiment is that in the latter the first conductive material  31  is formed on the first surface  301  by electroplating and totally covers the first testing pads  303 . The first testing probe unit  23  may electrically connect to any portion of the first conductive material  31 , and the second testing probe unit  24  electrically connect to the second testing pads  304  so as to measure the electrical characteristics of the substrate  30 .  
         [0022]     In the testing method of the second embodiment, the conductive material  31  is formed on the first surface  301  by electroplating and totally covers the first testing pads  303  so as to electrically connect all of the first testing pads  303 . Therefore, the first testing probe unit  23  may electrically connect to any portion of the first conductive material  31  to measure the electrical characteristics of the substrate  30 . Also, the electrical characteristics of the substrate  30  can be easily measured, the testing process and testing time can be reduced, and whether the substrate  30  is good or not can be easily recognized. It should be noted that a second conductive material may be formed on the second surface  302  by electroplating and totally covers the second testing pads  304  so as to electrically connect all of the second testing pads  304 . In addition, referring to  FIG. 5B , the testing fixture may comprise a first testing probe unit  27  and a plurality of second testing probe units  28 . In the embodiment, the first testing probe unit  27  has two first testing probes  271 ,  272 , and each second testing probe unit  28  has two second testing probes  281 ,  282 . By utilizing the first testing probe unit  27  and the second testing probe units  28  to electrically connect to the first testing pads  303  and the second testing pads  304  respectively, the electrical characteristics of the substrate  30  can be easily measured, the testing process and testing time can be reduced, and that the substrate  30  is good or not can be easily recognized.  
         [0023]      FIG. 6  shows a substrate according to a first embodiment of the present invention. The substrate  40  comprises a first surface  401  and a second surface  402 . The first surface  401  has a plurality of first testing pads  403 . The second surface  402  has a plurality of second testing pads  404 . The first testing pads  403  electrically connect to the second testing pads  404  to form a plurality of circuits  405 . A first conductive material  41  is formed on the first surface  401  and electrically connects two first testing pads  403 . It should be noted that in other embodiment a second conductive material may be formed on the second surface  202 , and electrically connect at least two second testing pads  404  on the second surface  402 . The first conductive material  41  comprises silver glue in this embodiment, for example. The first conductive material  41  is line-shaped and electrically connects at least two first testing pads  403 . In other application, the circuits  405  of the substrate  40  can be electrically connected by connecting two first testing pads  403 .  
         [0024]     Because the first conductive material  41  electrically connects two first testing pads  403  on the first surface  401 , the electrical characteristics of the substrate  40  can be easily measured by the testing fixture, the testing process and testing time can be reduced, and whether the substrate  40  is good or not can be easily recognized.  
         [0025]      FIGS. 7A and 7B  show a substrate  50  according to a second embodiment of the present invention. The difference between the substrate  50  of the second embodiment and the substrate  40  of the first embodiment is that a first conductive material  51  is formed on the first surface  501  and electrically connects all of the first testing pads  503 . It should be noted that in other embodiment a second conductive material may be formed on the second surface  502  and electrically connects all of the second testing pads  504 .  
         [0026]     The first conductive material  51  electrically connects all of the first testing pads  503  on the first surface  501  to form a testing surface, so that the electrical characteristics of the substrate  50  can be easily measured by utilizing the testing line, the testing process and testing time can be reduced, and whether the substrate  50  is good or not can be easily recognized.  
         [0027]     Referring to  FIG. 8 , it shows a substrate  60  according to a third embodiment of the present invention. The difference between the substrate  60  of the third embodiment and the substrate  40  of the first embodiment is that a first conductive material  61  is formed on the first surface  601  by electroplating and electrically connects all of the first testing pads  603 . It should be noted that in other embodiment a second conductive material may be formed on the second surface  602  by electroplating and electrically connects all of the second testing pads  604 . The first conductive material  61  comprises copper in this embodiment, for example.  
         [0028]     The first conductive material  61  covers the first surface  601  and electrically connects all of the first testing pads  603  so as to form a testing surface, so that the electrical characteristics of the substrate  60  can be easily measured by utilizing the testing surface, the testing process and testing time can be reduced, and whether the substrate  60  is good or not can be easily recognized.  
         [0029]     While the embodiments of the present invention have been illustrated and described, various modifications and improvements can be made by those skilled in the art. The embodiments of the present invention are therefore described in an illustrative but not restrictive sense. It is intended that the present invention may not be limited to the particular forms as illustrated, and that all modifications that maintain the spirit and scope of the present invention are within the scope as defined in the appended claims.