What are the factors that cause the LED light source to turn black?

1、 Oxidation: Silver can easily react with oxygen in high temperature and humidity environments, producing black silver oxide. After confirming that the blackening of the light source is caused by oxidation of the silver plating layer, Duoen Lighting will advocate for customers to further check the airtightness of the light source and lamp, and eliminate the pathway of moisture infiltration.

2、 Carbonization: Based on experience, the data shortcomings of the six major raw materials (chips, brackets, solid crystal adhesives, bonding wires, fluorescent powder, and packaging adhesives) and the process shortcomings of the three major packaging processes (solid crystal, wiring, and gluing) of LED light sources can all lead to extremely high temperatures in the light source, resulting in partial or total blackening of the light source and carbonization of the light source. Irrational heat dissipation planning of LED lamps, low thermal conductivity of heat dissipation data, unreasonable power supply planning, and too many defects of reflow soldering welding will also form light source carbonization.

3、 Vulcanization, chlorination and bromination: the silver plating layer on the LED bracket will generate silver sulfide when touching sulfur gas, and silver halide sensitive to light will be generated when touching acid nitrogen containing chlorine and bromine gas, which will lead to blacking and failure of the light source. Sulfur/chlorine/bromination of light sources may occur in every stage of the production, storage, aging, and use of LED light sources and lamps. After being diagnosed with sulfur/chlorine/bromination due to blackening of the light source, the customer needs to select a detailed sulfur removal plan based on the stage of sulfur/chlorine/bromination onset.

4、 Chemical incompatibility: Blackening of LED light sources may also be caused by chemical contamination, which often occurs in sealed lamps with little or no air activity. However, the blackening of the light source is only superficial, and factors such as sulfurization, chlorination, bromination, oxidation, carbonization, and chemical incompatibility can all lead to the blackening of the LED light source. Due to the lack of professional testing equipment and personnel, most LED companies usually rely on experience and speculation when conducting blackening failure analysis, lacking scientific testing data.