While the UVLED chip technology has made great progress, the packaging methods that exist in the domestic market mainly follow the packaging methods of white light LEDs. Although the white LED packaging method can be used to meet the requirements of low reliability requirements (such as currency verification, nail art, etc.). However, almost all of the current packaging methods of white light LED packaging use organic materials such as resin for packaging to varying degrees, so the following problems will occur:
(1) UVCLED customized manufacturers tell you that ultraviolet radiation causes colloidal yellowing, which reduces the service life of light-emitting diodes
Especially for the wavelength band below 365nm, the visible light LED packaging method cannot meet the requirements, because as the wavelength band becomes shorter, the radiation energy becomes stronger, and the UV resistance of organic resin materials decreases sharply, which affects the life and stability of UV LEDs.
(2) Thermal stress causes failure
In fact, there must be two interface substances, organic and inorganic, mainly in the traditional visible light encapsulation method. In terms of thermal effects, the coefficient of thermal expansion of inorganic substances is much smaller than that of organic substances. Therefore, it will inevitably lead to the problem of thermal stress. This leads to product failure.
(3) Wet stress and impurity intrusion lead to failure
Whether it is silica gel or silicone resin, it has oxygen and moisture permeability to varying degrees. Therefore, the switching moment will be generated, and the force will be generated due to the evaporation of water vapor, which will lead to failure. In addition, due to the existence of oxygen and moisture permeability, it is inevitable that other impurities will invade and cause failure.
