## 3 Results  
The degradation paths of LEDs under S1-S5 stress are shown in the Figure 5 above. To avoid a cluttered image, only 9 LED degradations and the average degradation path of 1 LED path are shown under each stress, as shown in Figure 5 above. Figure 5 shows the average degradation path of 300 LEDs under S1-S5 stress. Among them, S42 represents the second test sample under S4 stress. The tenth datum in each figure in Figure 5 is the average of the LOP BE of 60 data. Take Figure 5 as an example. When the initial situation is, according to the BE formula, the initial LOP BE is 0, and the \(x\)-axis is the measurement time of the LOP BE. The measurement time interval  
Figure 5: LOP degradation curves of LEDs under 5 different stresses. under different pressures is also different. It should be noted that the time line of the \(x\)-axis in Figure 5a-e is not proportional but only represents the measurement time. For example, the \(x\)-axis distance of 0-24 h is the same as 2091-3105 h, but the actual measurement time difference is very large. However, the \(x\)-axis in Figure 5f is proportional to time. Due to the relationship of retaining two decimal places, according to rounding, when the LOP BE value of the tested LEDs is \(-0.295\) to \(-0.305\), the LED is declared to be failed. The time recorded at this time is the LED failure time. When all 300 LEDs fail, the test is declared to be over. We can clearly see that the degradation is relatively mild under S1 stress, and the degradation of LEDs under S2 and S3 stresses will accelerate when the humidity and current are increased. Comparing the degradation of LEDs under S4 and S5 stresses, we can find that temperature is still the main stress that causes LED degradation, and the degradation of LEDs under S4 stress is also the fastest, followed by the degradation of LEDs under S5 stress. Through Figure 5f, we can clearly see the average degradation curve of 60 LEDs from S1 to S5, where the \(x\)-axis of each point is the average degradation time of the 60 LEDs, and the \(y\)-axis is the average LOP BE. Under S1 stress, we found that the LOP change of the LED in the first 2091 h was positive; that is, the brightness was higher than the initial value; the LOP change rate also increased from 24 h to 72 h of S4 stress and from 120 h to 168 h of S5 stress. This may be the initial stage of LED self-luminous attenuation; that is, in the early stage of LED use, it may experience a stage of slight increase in light intensity. This is because, during the \"aging\" process of the device, the junction temperature changes, and material properties gradually stabilize, resulting in a slight increase in luminous efficiency. However, this phenomenon does not exist in the high-humidity S2 and S3 stresses, which may be due to the influence of high humidity on the initial growth of LOP. The Pearson Correlation Coefficient of S1-S5 is shown in Figure 6 below. The Pearson Correlation Coefficient is an indicator used in statistics to measure the linear correlation between two variables. Its value is between \(-1\) and \(1\). When the value is 1, it indicates a perfect positive correlation, which means that when one variable increases, the other variable will also increase linearly. When the value is \(-1\), it indicates a perfect negative correlation, which means that when one variable increases, the other variable will decrease linearly. When the value is 0, it indicates no linear correlation, which means that there is no linear relationship between the two variables. In Figure 6, we can see that the Pearson Correlation Coefficient of S2 and S3 is 0.98. According to Table 2, the effect of current on the life of LEDs is strongly correlated; the Pearson Correlation Coefficient of S1 and S2 is 0.91, indicating that the effect of humidity and current on the life of LEDs is strongly correlated. The minimum value of the Pearson Correlation Coefficient between  
Figure 6: S1–S5 Pearson Correlation Coefficient. all stresses is 0.88, which also shows a high positive linear correlation.