In general, the reliability of an LED is characterized by a half-life (ie, the time when the light output is reduced to half the initial value). The reliability test of the LED is about 10,000 to 100,000 hours, including electrostatic sensitivity characteristics, lifetime, Testing of indicators such as environmental characteristics. The electrostatic sensitivity characteristic refers to the electrostatic discharge voltage that the LED can withstand. Some LEDs have high resistivity and the distance between positive and negative electrodes is very short. If the electrostatic charge at both ends accumulates to a certain value, this electrostatic voltage will break through the PN junction. In severe cases, the PN junction will break down and the LED will fail. Therefore, it is necessary to test the electrostatic sensitivity characteristics of the LED to obtain the electrostatic discharge fault threshold voltage of the LED. At present, the human body mode, the machine mode, and the device charging mode are generally used to simulate the electrostatic discharge phenomenon in real life.
In order to observe the variation of the optical performance of LEDs in the long-term continuous use, it is necessary to carry out sampling tests on LEDs, and obtain LED life parameters through long-term observation and statistics. Tests on the environmental characteristics of LEDs often use various types of natural intrusions encountered in the application of analog LEDs, generally: high and low temperature impact test, humidity cycle test, moisture test, salt spray test, sand dust test, irradiation test, vibration and Impact test, drop test, centrifugal acceleration test, etc. The specific items for testing the reliability of low-power LEDs are as follows:
1. Solder heat resistance: 260 ° C ± 5 ° C, 5 Sec, no abnormal appearance and electrical characteristics.
2. Temperature cycle test: 85 ° C (30 min) --- conversion 5 min --- 40 ° C (30 min) for 1 cycle, 50 cycle required, no abnormal appearance and electrical characteristics.
3. Thermal shock test: 100 ° C (5 min) --- conversion 10 sec --- 10 ° C (5 min) 1 cycle, 50 cycle required, no abnormal appearance and electrical characteristics.
4. High-temperature storage test: 1000Hrs was placed in a temperature of 100 ° C, and there was no abnormality in appearance and electrical characteristics.
5. Low-temperature storage test: 1000Hrs was placed in a temperature-40 °C environment, and there was no abnormality in appearance and electrical characteristics.
6. High-temperature and high-humidity placement test: 1000Hrs was placed in an environment of temperature 85 ° C / relative humidity 85% RH, and there was no abnormality in appearance and electrical characteristics.
7. Pin tension test: Gravity/30Sec is applied according to the size of the pin cross-sectional area, the pin must be free from pull-out and loose, and the electrical characteristics are not abnormal.
8. Pin bending test: Apply gravity according to the size of the cross-sectional area of ​​the pin, bend ±90 degrees (3mm away from the body) 2 times, the pin must be broken and loose, and the electrical characteristics are not abnormal.
9. Life test: Apply IF current, 1000 Hrs continuous operation, no abnormal appearance and electrical characteristics.
Note: After the environmental and life reliability test, 24Hrs should be placed at 25 ° C to test the electrical characteristics.
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