226
10 Reliability Analysis of Group III Nitride LEDs Devices
Fig. 10.15 The estimated
lifetime of the semiconductor
lighting system
0
100
200
300
400
0
0.2
0.4
0.6
0.8
1
Time [kh]
probability of system failure
System
methods. But in practice, the estimated reliability for the LED lighting application
systems is a daunting task. Not only is there a wide variety of components in the
LED system, in addition to a large number of unknown failure modes and failure
mechanisms, but also the failure mechanisms can affect each other. In order to know
the reliability of the entire LED system, it is not only necessary to test the reliability
performance of the entire system, but also to test the reliability performance of each
component. For the long-life LED systems, it is estimated to extrapolate its reliability under the normal conditions by accelerating aging tests. For the accelerated-life
experiments, if you simply increase stresses such as temperature, electrical power
and so on, it will lead to new failure models in some components. Therefore, the
accelerated-life experiments should be carried out under certain estimation and evaluation conditions. Firstly, the failure of each component is not equal to the system
failure. Each component in the system exhibits its own different failure mode, which
require three different aging conditions for accelerated testing. Furthermore, the analysis model has to obeys the physical mechanism of the failure. When determining
the stress of the accelerated aging experiment in the system and components, the
implementation plan should be set according to the actual research results. For the
LED lighting systems, not only temperature, humidity, electrical power and mechanical stress have to be considered, but also the effect of light on them. In addition,
it is necessary to know the failure modes of the connection interface for the LED
systems. Accelerated reliability testing methods involving LED modules and driving
systems need to be further explored and improved.
10 Reliability Analysis of Group III Nitride LEDs Devices
Fig. 10.15 The estimated
lifetime of the semiconductor
lighting system
0
100
200
300
400
0
0.2
0.4
0.6
0.8
1
Time [kh]
probability of system failure
System
methods. But in practice, the estimated reliability for the LED lighting application
systems is a daunting task. Not only is there a wide variety of components in the
LED system, in addition to a large number of unknown failure modes and failure
mechanisms, but also the failure mechanisms can affect each other. In order to know
the reliability of the entire LED system, it is not only necessary to test the reliability
performance of the entire system, but also to test the reliability performance of each
component. For the long-life LED systems, it is estimated to extrapolate its reliability under the normal conditions by accelerating aging tests. For the accelerated-life
experiments, if you simply increase stresses such as temperature, electrical power
and so on, it will lead to new failure models in some components. Therefore, the
accelerated-life experiments should be carried out under certain estimation and evaluation conditions. Firstly, the failure of each component is not equal to the system
failure. Each component in the system exhibits its own different failure mode, which
require three different aging conditions for accelerated testing. Furthermore, the analysis model has to obeys the physical mechanism of the failure. When determining
the stress of the accelerated aging experiment in the system and components, the
implementation plan should be set according to the actual research results. For the
LED lighting systems, not only temperature, humidity, electrical power and mechanical stress have to be considered, but also the effect of light on them. In addition,
it is necessary to know the failure modes of the connection interface for the LED
systems. Accelerated reliability testing methods involving LED modules and driving
systems need to be further explored and improved.