Determination of the dice forward I-V characteristics of a power diode from a packaged device and its applications

The forward voltage drop (VF) of a power diode is an important electrical parameter for a power diode. Diode with excessive VF can be due to either defects in wafer fabrication or soldering processes. To identify if the defects in soldering process is the root cause to excessive VF, the obvious method will be the method to extract the series resistance from the diode. However, the present series resistance extraction methods are either inaccurate or requires extensive computation time, and they are not practical for failure analysis and process monitoring. In this work, a modified series resistance extraction method is developed. Experimental results showed that the modified method is accurate, and the computation time is short.