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 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 referring to fig8 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 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.