Investigation of WLCSP corrosion induced reliability failure on halogens environment for wearable electronics

Continuous miniaturization of microelectronic devices is enabling more portable and wearable electronic products such as thinner smart phones and smart watches. WLCSP (Wafer Level Chip Size Package) has been widely adopted for portable and wearable electronic products due to its compactness. Microelectronic devices in wearable products may be exposed to chlorine and fluorine because they come in direct contact with the human body under wearing condition. Products of chlorine corrosion have been found in WLCSP product evaluations, thus it is necessary to investigate WLCSP corrosion resistance and the factors affecting its corrosion reliability.