LED RELIABILITY
Reliability
The reliability of the performance of LED (light emitting diode) is almost always better than incandescent lamps, neon and other lights. Furthermore, the lights of today are much higher than the precision of the first instruments used in lamps, LED. Improved assembly methods and the development of structures permitted in conjunction with the development of new materials and mass production of high reliability, high brightness LED in all colors such as white.
Lifetime
The light generated in the LEDs, through emission of energy from the recombination of electrons and holes in the active zone. Because this process is very different from that of other light emitting semiconductor devices, there are several mistakes observed in typical electronic components, other forms of humiliation, are the distinctive features of production devices, such as lamps, LED.
The life of an LED is defined as the time for light to reach 50% of original value. The average life of Manufacturers led identifies is 100,000 hours. This does not mean that the LED will stop working after 100K hours, in fact, most of the LED above the fixed price for thousands of hours. This means that after 100,000 hours, the LED will be half as bright as the original brightness level.
The useful life of an LED is usually estimated by extrapolation from measured data or estimates of the rapid test. Speed test), the most extreme LED (high temperature and / or currents higher than expected during normal operation. This is necessary because it is often difficult and impractical to test in reality an LED 100.000 hours or more than 10 years. The main concern rapid testing of the LED is to understand exactly how to translate the results during normal operation.
Longevity Characteristics
As mentioned above, the luminous intensity of LED lamps typically slow decrease over time. It is important to choose the LED lamps according to the reliability of equipment which must be used. Although most evidence suggests the market, the deterioration of the LED is about 50% to 100,000 hours, which is not always the case. For example, many white LED lamps can achieve 50% of original brightness to around 10,000 30,000 hours. On the other hand, some may InGaAlP red LED lights last for 200,000 hours of life.
It is important to note the following when applying the reliability of the LED lamp manufacturer.
Temperature Conditions?
It is often necessary to obtain information such as characteristics of the resistance temperature (high temperatures in May, at normal temperature and low temperature) a discrete LED changes depending on the context in which the LED lights are used effectively and / or controlled.
Humidity Conditions
Depending on the package, die type and material used to manufacture an LED, operating the LED under high-humidity and/or high-temperature conditions can dramatically reduce its lifetime as shown by the above simulated data.
Forward Current Conditions?
Because lattice defects increase with use, the luminous intensity of LEDs gradually declines over time. The speed of accumulation of lattice defects depends on the amount of forward current used to operate the LED. The higher the current, the faster the degradation. It is best usually to operate an LED at the typical recommended values specified by the manufacturer.??
Others?
It is also important to know the conditions, if factors such as vibration, shock, gas or UV-LED can intervene.
Recent improvements tend to reduce the use of lower lamp LED. The results of some long-term studies on the characteristics of longevity far show that the brightness is always worse. Please note, however, does not mean the absence of reducing the brightness during longevity tests, the LED will not deteriorate to a point in his life.
As a result of the continual improvement in LED performance and reliability, LED’s are becoming increasingly prevalen in applications such as variable message signs (both single color and full color), traffic control devices such as stop lights, pedestrian signals and barricade lights as well as replacements to various incandescent white light applications such as task lighting, flashlights and night lights.