Research On High Light Efficiency Of Ultraviolet Light-emitting Diode Packaging And Its Application

Ultraviolet light-emitting diodes(UV-LED)have the advantages of compact structure,controlled wavelength,low power consumption,instant start,and mercury-free,have gradually replaced traditional ultraviolet light sources such as mercury lamps.Meanwhile,the outbreak of the Covid-19 is significantly promoting the application of UV LEDs in the field of sterilization.Due to the low light extraction efficiency of the UV-LED chip and the high ultraviolet photon energy,higher requirements are put forward on the packaging technology of the UV-LEDs.In order to achieve high luminous efficiency and high reliability packaging of UV-LEDs,this article used all-inorganic technology to prepare highly reliable UV-LEDs,and proposed a high luminous efficiency packaging scheme for enhancing the light extraction efficiency of UV-LEDs,and finally used the above UV-LED lamps to designed a sterilization light source for the sterilization box.The main research contents include:1)UV-LED packaging design and process optimization: Aiming at the problem of ultraviolet light destroying the molecular structure of organic materials,we proposed an allinorganic UV LED packaging structure,and its manufacturing process was optimized.A quartz plate was used to extracting UV light.The three-dimensional ceramic substrate fabricated by multi-layer electroplating process was used for heat dissipation.The quartz plate was bonded above the substrate through solder bonding to achieve high-reliability and hermetic packaging.In addition,the packaging process was improved,the screen-printing process was proposed to coat metal solder on the substrate dam to improve the packaging efficiency.2)High luminous efficiency packaging technology of near UV-LED: Aiming to suppress the total reflection loss between the different interfaces in the packaging of NUVLEDs,an optimal quartz lens and a silicone layer were proposed to improve the light efficiency of NUV-LEDs.First,the feature size of the quartz lens was optimized by optical simulation.Then,different lenses were prepared and applied in the packaging of NUVLEDs.As a consequence,the silicone encapsulation layer increased the output light power of the NUV-LEDs by 20.19%,and the optimized quartz lens increased the output power of the device by 53.30%.3)High luminous efficiency packaging technology of deep UV-LED: Aiming to improve the extraction of the sidewall emission of the DUV-LED chip,we proposed a packaging structure in which a three-dimensional quartz lens and a flat ceramic substrate were bonded together.First,the feasibility of the three-dimensional quartz lens was initially verified by optical simulation.Then,different lenses were fabricated and applied for the packaging of DUV-LEDs.As a consequence,the three-dimensional quartz lens increased the output power of the DUV-LEDs by 25.93%,and achieved the beam angle of the device to 153.2°.4)Deep UV-LED light source design for sterilization: In order to promote the application of UV-LEDs,a DUV-LED light source used in the sterilization box was designed.First,the sterilization mechanism of deep ultraviolet light was analyzed,and the effective sterilization radiation dose was calculated.Then,through optical simulation,determined the light source scheme using three deep ultraviolet LED lamp beads with a beam angle of 120° in a linear arrangement.Finally,the biological experiment of ultraviolet light sterilization was designed to verify the simulation results.The experimental results showed that the sterilization rate of different bacteria in the sterilization box all exceeded99.7% after 30 minutes of UV irradiation.