wave signal with a rising falling time of 200 pico seconds is applicable instead for a smaller sized electronic device like a packaged device a higher resolution is required and thus a square wave signal having a rising falling time of 35 pico seconds will be used therefore tdr reflected waveform analysis can be performed for a system composed of several components for example a pcb including an ic package connected by solder balls to find out a disconnection location in the system the failed component or even the location of disconnection in the component can be determined as shown in fig2 a printed circuit board pcb 10 is a first type of standardized sample 20 as shown in fig3 the pcb 10 with a solder ball 11 thereon is a second type of standardized sample 21 as shown in fig4 the pcb 10 having the solder ball 11 thereon and a substrate 12 soldered on the solder ball 11 is a third type of standardized sample 22 a square wave signal of a voltage of 0 5 volts and having a very short rising falling time is emitted from the signal generator 2 of the tdr input and into a predetermined position of the conducting wire of the pcb 10 of the first type sample 20 meanwhile the oscilloscope 1 of the tdr receives.