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A white light-emitting diode (WLED) with chip-scale packaging (CSP) has wide applications due to its high power density, small size, and high process integration. The phosphor converter of the CSP WLED needs to endure huge heat shock from LED chips and phosphor conversion. In this work, we proposed a phosphor-in-glass (PiG)-based CSP for high-power WLEDs. A wafer PiG was prepared by printing and sintering a phosphor glass film on a glass plate and then cut into a chip-scale PiG for the fabrication of PiG-CSP WLEDs. The optical performances of PiG-CSP WLEDs were optimized by adjusting the film thickness of PiG. Consequently, the PiG-CSP WLED emits a cool white light with optimal light performances at a film thickness of 88 $\mu \text{m}$. The related luminous efficiency (LE), correlated color temperature (CCT), and chromaticity coordinate are 108.8 lm/W, 5796 K, and (0.3256 and 0.3467), respectively. The down-PiG-CSP structure achieves higher LE and lower CCT than the up-PiG-CSP structure. Compared with the traditional phosphor-in-silicone (PiS)-CSP WLED, the PiG-CSP WLED avoids the carbonization of the converter and displays excellent thermal stability under high input current. The results determine that the PiG-CSP is a reliable and efficient packaging technology for high-power WLEDs. [ABSTRACT FROM AUTHOR]

In this work, we proposed a chip on thermoelectric cooler (chip-on-TEC) for the active thermal management of high-power light-emitting diode (LED). The chip-on-TEC was prepared by electroplating a circuit layer on the cold-side substrate of thermoelectric cooling (TEC) and directly attaching LED chips on the circuit layer. Due to the Peltier effect of TE materials and the low thermal resistance of chip-on-TEC structure, the heat generated from the chips can be dissipated to the surrounding environment effectively. The performances of chip-on-TEC were studied by using the thermal simulation and packaging experiment. Compared with the traditional packaging structure, the working temperature of chip-on-TEC is greatly reduced under various chip currents. At the chip current of 1.0 A, the chip-on-TEC can reduce the working temperature from 232 °C to 114 °C (the reduction of 51%). Moreover, the light output power of LED is increased by 35.3%. The chip-on-TEC also can improve the light intensity and the light saturation point of LED. The results demonstrate that the chip-on-TEC is a promising thermal management for high-power LED packaging. [ABSTRACT FROM AUTHOR]

In this letter, an all-inorganic and hermetic packaging technology was proposed for deep-ultraviolet light-emitting diodes (DUV-LEDs). The package was fabricated by bonding the quartz cap on the three-dimensional (3D) ceramic substrate at low temperature. The bonding layer was formed by an inorganic adhesive and presented a reliable and dense state. The average air leakage rate of the packaging structure was $3.79\times 10^{-8}$ Pa $\cdot$ m3/s and the average tensile strength between quartz cap and ceramic substrate was 4.3 MPa. The peak emission intensity was at 280 nm and the peak width at half height was about 10 nm. At the current of 40 mA, the voltage was 5.63 V and the light output power was 3.0 mW. After the accelerated aging test, the light output power of packaged DUV-LEDs only decreased by 14.9%, while that of unpackaged reference decreased by 55.8%. [ABSTRACT FROM AUTHOR]