The cause of the light decay of LED lamps

    LED light decay problem

    The problem of LED light decay is a problem that LED lamps have to face. Careful observation will find that LED sometimes has uninterrupted light decay, and light decay seriously affects the use of LED lamps. At present, the light decay phenomenon of white LEDs on the market is more common. This may be one of the first issues in the march towards civilian lighting.

    What is the cause of led light decay?

    There are two main factors of LED light decay:

    First, the quality of LED products themselves:

1. The LED chip used has a bad physique and a faster brightness attenuation, resulting in more serious quality light decay problems.

2, the production process has defects, LED chip heat dissipation can not be well derived from the PIN foot, resulting in LED chip temperature is too high to make the chip attenuation intensified.

LED light decay due to quality problems is irreversible. Although such LED lights are also environmental protection products, they also cause extreme waste to a certain extent. For cutting corners and deceiving consumers with shoddy quality, it should be vigorously rectified, and the market environment will be better.

    Second, the use of conditions of use:

1, LED is constant current drive, and some LEDs use voltage drive, so that LED attenuation is excessive.

2. The driving current is greater than the rated driving conditions.

In fact, there are many reasons for the light decay of LED products, but the most critical of which is the problem of heat, although many manufacturers do not pay special attention to the problem of heat dissipation in secondary products, but under the long-term use of these secondary LED products, the degree of light decay will be higher than that of LED products that focus on heat dissipation.

    The thermal resistance of the LED chip itself, the influence of silver glue, the heat dissipation effect of the substrate, and the colloidal and gold wire are also related to light decay.

    Factors affecting the quality of LED lamps and lanterns

    First of all, choose what kind of LED white light. This is very important, and the quality of LED white lights can be said to be an important factor. Secondly, the LED lamp beads work at ambient temperature. According to the data of the aging of a single LED white lamp, if the LED white light has only one light to work, and at the same time, the ambient temperature it is in is 30 degrees, then the temperature of the bracket when the single LED white light works will not exceed 45 degrees. At this time, the life of this LED will be ideal.

    If there are 100 LED white lights lit up at the same time, and the interval between them is only 11.4mm, then the temperature of the bracket of the LED white lights around the lamp pile may not exceed 45 degrees, but those LED white lights in the middle of the lamp stack may reach a high temperature of 65 degrees.

    At this time, the LED lamp beads are a test. Then, those LED white lights that are concentrated in the middle will theoretically decay a little faster, and the LED white lights around the lamp pile will have a slower light decay. Again, the LED lamp beads are designed for working electrical parameters. According to the experimental results, the lower the driving current of the LED white lamp, the smaller the heat emitted, and of course, the smaller the brightness. According to the survey, the design of LED solar lighting circuits, led drive current is generally only 5-10mA. The lamp beads used in the lamp are huge products, such as more than 500, or more, the drive current is generally only 10-15mA, and the drive current of the general popular LED application lighting is only 15-18mA, and few people design the current to more than 20mA.

    The experimental results also show that under the drive current of 14mA, and the lid is not airtight, the air temperature inside reaches 71 degrees. Low-decay products, thousand hours of light decay is zero, 2000 hours of light decay of 3%, which shows that this low-end LED white lamp in such an environment has reached its maximum, and then it is a damage to it. Because the aging plate used for aging does not have a heat dissipation function, the heat generated by the LED when working is basically unable to be transmitted to the outside.