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AlGaN‐based deep ultraviolet light‐emitting diodes (UV LEDs) have gained rapidly growing attention due to their wide applications in water purification, air disinfection, and sensing as well as optical communication. Moreover, deep UV radiation has been verified as one of effective way to inactivate COVID‐19. However, although numerous efforts have been made in deep UV LED chips, the reported highest external quantum efficiency (EQE) of them is 20.3%, which is far lower than that of visible LEDs. The EQE of commercial packaged AlGaN‐based deep UV LEDs is usually lower than 5%, which will cause serious reliability problems as well. Therefore, it is very urgent to improve EQE and reliability of the devices from packaging level. In this review, a systematical summarization about the packaging technologies of AlGaN‐based deep UV LEDs has been analyzed and future prospects have been made as well. Firstly, this work provides a brief overview of the devices and analyzes why the packaging level reduces EQE and reliability in theory. Then, systematically reviews the recent advances in packaging technologies and deep UV micro‐LEDs. Finally, conclusions and outlooks are given as well. This review is of great significance for promoting the development of the packaging technologies for AlGaN‐based deep UV LEDs. [ABSTRACT FROM AUTHOR]

A kind of chips on board (COB) package of light emitting diode (LED) light source is designed and produced. By reducing the current density and using the mirror aluminum substrate with high reflectivity to improve the luminous efficiency. Meanwhile, three kinds of red phosphors with peak wavelength of 630 nm, 631 nm and 639 nm are added on the basis of yellow‐green phosphors, which increase within the range of red light LED spectrum composition, improve the LED color rendering index. The measurement results show that under 500 mA forward current, the luminous flux density of LED on the luminous surface with an area of 227 mm2 reaches 14.4 lm/mm2, the luminous efficiency reaches 175.5 lm/W, and the color rendering index reaches 89.3. It is found in the process of measuring the LED color temperature changes slightly with the current change, and by calculating that the proportion of blue photons in the LED spectrum is increasing gradually, the cause of this phenomenon is the phosphor excitation efficiency is saturation when the optical power density is high, which is influenced in two aspects: the proportion of photons absorbed by phosphor or the phosphor excitation efficiency decreases, the two factors together or separately cause the phosphor excitation saturation effect. [ABSTRACT FROM AUTHOR]