At present, although the theoretical life of the LED can be achieved 50kh, however, in actual use, due to various factors, LED lights often amounted to less than such a theory of life, premature failure phenomenon, which greatly hindered the LED as a new energy-saving the pace of the products. LED lamp design failure carry out systematic analysis, and proposed some improvement measures, and to expect to be able to improve the actual service life of the LED.
一、LED spot failure modes
LED failure modes: chip failure, the package fails, the thermal stress failure, electrical overstress failures and assembly failure, especially in chip failure and package failure is most common. The text will analyze these types of failure modes.
一、LED grow lights chip failure modes
Chip failure refers to the chip itself get failure or other causes chip failure. The reason of this failure are many: the die crack is due to improper bonding process condition, resulting in a larger stress, with the accumulation of heat generated by the thermo-mechanical stress, with the accumulation of heat generated by the term-mechanical stress also will strengthen, causing the chip to produce micro-cracks, work when injected into the current will be further exacerbated by the micro crack expanding until the device fails completely. Second, if the chip active are injured, it will lead to gradual degradation during power-up failure, the same can also cause the lamps in the use of a coherent state of serious decline until it does not shine. Furthermore, if the chip bonding technology is bad, chip bonding layer is completely out of the bonding surface and the sample will open to lapse. The same will cause the LED lamp design in the course of “dead light” phenomenon occurs. The bad chip bonding process may be due to the use of silver paste expired or the exposure time is too long, silver paste is too small, the curing time is too long, solid crystal base surface contaminated.
(2) package failure
Package failure is improper package design or production processes lead to device failure. Epoxy materials, packaging occur in the course of the degradation problem, resulting in reduced life of the LED.