Patent ID: 9557368
Date: 2017-01-31
CPC Classifications: G01R

Claim:
1. A method for measuring thermal electric characteristics of a light emitting diode (LED) device, comprising the steps of: providing at least one current to the LED device over a time interval; recording a voltage transient response of the LED device, wherein the voltage transient response has a plurality of time segments different in gradient; computing a voltage difference from one of the plurality of time segments in the voltage transient response; transferring the voltage transient response to a logarithm scale by using the logarithm, and obtaining the voltage transient response from a heating voltage or a testing voltage of the LED device, wherein the heating voltage and the testing voltage are generated by a heating current and a testing current, respectively; summing up the voltage transient response over a time interval; and determining whether the LED device is defective based on the voltage difference, wherein the voltage difference is thermal dependent.