Research For Improving The Reliability Of The LED Driver IC

LED is a clean, solid-state light source. It is not only long life, and is controllable.Now, the energy consumption is Increasing, LED’s energy saving and environmentalprotection can save a lot of electricity. This makes it to be one of the world’s hottesthigh-tech in recent years. With the improvement and mature of LED lighting industrychain, power driver has become an important part of it. According to the research, LEDlighting failure, more than70%are caused by the drive power.There are several main reasons leading to low reliability of the LED driver. First, isclose to a heat source. The energy of the LED20%to30%in the form of visible lightradiated out, the remaining majority of the energy is consumed in the form of heat in theLED. So, the self-heating of the LED light source is more serious. LED drivers areusually placed inside the lamps. The ambient temperature around it is very easy to reach50-60°C. In the case of no dimming mode, LED drive is close to full capacity. In suchhigh ambient temperatures, the life of the drive is seriously affected by the higher powerconsumption of the drive. The LED usually used in roads, squares and other outdoorlighting occasions, vulnerable to external exposure, lightning and other naturalphenomena. These will result in the latter part of the large-scale application of LEDsemiconductor lighting maintenance series ills.For these reasons, my thesis is dedicated to how to improve the reliability of theLED driver IC. The improvement is from the circuit to the layout, process, package, andapplication links. The main content is:1. Increase the over-temperature protection, overvoltage protection, under-voltageprotection functions in circuit. Drive start protection mode in the event of inclementweather, effectively protect the driver chip from damage. And the protection circuit isintegrated into the chip, reducing the occupied area of the PCB, and saving the cost.Dimming mode, not only linear dimming, and is also compatible with PWM dimming.Users can choose according to the practical application of flexible.2. In process and layout, doing the special instructions and processing for thelayout of the high-power devices, stress, metal traces, pads, and take measures to avoid the effects of electro-migration, antenna effect and latch.3. The chip directly bonds to the heat-sink, increases the level of the heatdissipation. Using a flip-chip mosaic, so that the heat conduction faster to more bottomline foil4. In order to solve the problem of the reliability of the LED products in the latterpart of the package, transport, storage and use of such links，need to pay attention to thedetails in the thermal stress, mechanical stress, radiation, chemical and biologicalcorrosion...