LED light bulb is composed of LED light source, LED driver, heat dissipation device and lens. Pick up several IP65 100W LED Flood Lights ings from different brands in the lighting market and carry through high temperature aging and overcurrent aging test. The result shows that the service time of the majority fixtures in the market is caused by lumen depreciation and color decline of LED light source, some fixtures are determined by the service time of LED driver and the rest results from other reasons, for instance, broken lens leads to LED fixtures out of work normally.
For LED light source, the service time is very long, but anyhow, it is available only when installed in fixtures. There is some difference between LED working alone or working in fixtures, such as working condition, electrical parameter, thermal parameter, and so on. In accordance with specific analysis, there are four modes that caused LED light source invalidity.
Overheat stress failure: if the internal temperature of LED is larger than rated value or LED heat periodically changes, it will lead to LED failure.
Packaging failure: during the process of LED produce or packaging, some incorrect methods or other reasons would result in LED failure.
Over electrical stress failure: if the instant current of LED is very high or even higher than rated value during working, it will also occur to LED failure.
Chip failure: LED chip may stop working for the reasons of self-defect or other factors.
Among of them, if any mode ceases to be effective, LED may run out at different extent. Meanwhile, it is likely to cause other modes failure and indirectly cause LED failure.