Failure Mechanism of LED Chip in Human Sweat

The failure phenomenon of semiconductor light emitting diode LED chips containing aluminum reflective electrodes under the action of human sweat was studied. Through scanning electron microscopy (SEM) and X-ray energy dispersive spectrascopy (EDS), the composition of different areas on the failed samples was analyzed contrastively. By simulating human sweat contamination test, the chip with optimized electrode process and structure was verified for comparison of failure. The results showed that the halogen chloride ions in sweat and the aluminum layer in the electrode were electrochemically corroded, which reduced the adhesion between the interface between the electrode and the epitaxial layer, and eventually led to the failure of the chip electrode after separation.