Most people think that the quality of all LED products is the same. There are many manufacturers and suppliers of LED, however, only a few of them can produce high-quality LED. For simple applications, low quality LEDs are enough. However, high quality LEDs must be used in many areas, such as consistency, reliability, or lighting, especially in harsh environments, such as highways, military / aviation, and industrial applications.
With the rapid growth of LED demand, manufacturers and assembly plants serving the global market are also growing rapidly. In addition to accurately selecting led suppliers through existing experience, OEM manufacturers must also examine their circuit design and assembly technology to ensure that they meet the design specifications, and whether the design provides enough heat dissipation capacity, because the main factor that causes led failure and performance inconsistency is overheating.
In order to eliminate the injustice in the test, many companies entrust a third party to test the LED assembly and circuit structure. An LED device can be tested or used for weeks in harsh environments. During the test, pressure, temperature cycling, voltage fixing / changing, current fixing / changing and other tests are carried out at the same time. Other tests under harsh environmental conditions determine whether the LED meets the requirements of the application. A large number of parameter changes before and after the test shall be recorded, and the changes of LED brightness, color and voltage drop shall be monitored at the same time.
Accelerated life cycle testing is a key test to avoid failure in special application areas. Testing helps ensure that LEDs that are expected to work at least 100000 hours, but fail ahead of time in 1000 hours are screened out. This is possible because the brightness of low-quality LEDs (or high-quality LEDs with unreasonable assembly design) will decrease after 1000 hours of operation. In fact, if a low-quality LED has a higher driving current, it will be brighter than a high-quality LED at the beginning of work. However, too high current will make the LED heat too fast, and the final result is that the brightness is dimmed or burnt.
In addition, there are also some examples in which the assembly technology has a greater impact on LED performance than the chip itself. The design engineer shall ask the LED supplier for the reliability specification of the LED, and shall also carry out the assembly test of the led to ensure that the higher the brightness is indeed better. Some excellent led suppliers can guarantee the reliability of their LED assembly technology for three years or longer, and can further provide the final LED products including high-quality LED and proper design for special applications.
Not every application needs high quality LED assembly technology. If the LED assembly does not meet the requirements of the harsh environment, the application may not have a greater safety risk, or if the maintenance cost of the final product is not very high, it may be more appropriate to use poor assembly technology.