Nicholas Herrick, Alpha Assembly Solutions
LED die package factors of higher current density, color uniformity and process residues require an understanding of both assembly and materials to improve reliability of chip on board and flip chip structures. A single LED failure results in a luminaire fail. Residues present on LEDs subjected to high temperature and humidity can impact color intensity, corrosion, poor interfacial bond strengths, insufficient wetting of underfill, leakage currents, electrical noise and field failures.
Cleaning process residues has been reported to improve wire bonding quality, reduce color shifts and prevent electrochemical migration. The test board for this study has sensors placed under and at the peripheral of the die package. The DOE will test leakage currents on both cleaned and uncleaned devices. Inferences from the data findings, conclusions and process recommendations will be reported.