White Light-Emitting Diodes With Visible Uniform Spectral Power Distribution Packaged With Phosphor-in-Silicone/Phosphor-in-Glass Stacked Structure

White light-emitting diodes (WLEDs) with a visible uniform spectral power distribution (SPD) were fabricated by integrating a blue LED chip and a phosphor-in-silicone (PiS)/phosphor-in-glass (PiG) stacked package. After adjusting the doping concentrations of phosphors (cyan, green and red) in the silicone encapsulant, the PiS was dispensed in the cavity of lead frame already bonded with a blue LED chip. Then the top surface of the PiS was covered with a PiG sheet. WLEDs with the PiS/PiG stacked package achieve a warm correlated color temperature (CCT) 4200K and a high color rendering index (CRI; Ra = 90.9, R9 = 73.0, and R15 = 85.9) at 350 mA. The full-spectrum index (FSI) of WLEDs with the PiS/PiG stacked packages is 4.24 in the wavelength range of 380 nm to 730 nm, respectively. Warm WLEDs with a visible uniform SPD and a high light quality can be fabricated through the PiS/PiG stacked package.