LED has been globally recognized as a new generation of environmentally friendly high-tech light, its long life, high reliability is to get the majority of consumers. Although from a technical point of view LED chip theoretical life of up 100000H, but because of the package, driving, cooling and other technologies applied to the life of the light source or luminaire for general illumination class can only reach 30000H, there are many on the market even with less than six months the product will be a problem. How to improve the reliability of LED lighting products has also been a business problem to be solved.
LED lighting product failure modes can generally be divided into: chip failure, package failure, failure of electrical stress, thermal stress failure, assembly failure. Through the analysis of these phenomena and the failure to improve, we can design and produce high-reliability LED lighting products to help. Based on the COB packaging technology and its application several common reasons for failure are analyzed and described the matter should be paid attention to summarize.
LED lighting products consists of three main components, namely cooling structure, power supply and lighting parts. Illuminated by the light source portion and a secondary optical light components (such as lenses, mirrors, and the diffuser plate) composed of
As LED lighting products in the light part of the core components, is the basis for achieving photovoltaic device performance. The technology is based on a package COB light source, which itself is no longer needed any automatic surface mount process, just to elicit positive and negative welding can be assembled into a simple matrix or lighting. Its important in LED lighting products key components.
These components are, in particular, COB, in most cases, are assembled by hand. This has resulted in the production process is likely to produce more than a potential failure in an automated process.
Based COB LED packaging technology is the multi-chip structure with different string and then wire bonding method to establish an electrical connection between the chip and the substrate, the final package from the use of encapsulants. This structure determines the interior of any single chip COB bad, will result in the remaining surplus chip current load increases, then rising single Vf value, the drive power supply into the output overvoltage condition, the output abnormalities lead flashing until the death of the remaining branches lights. The reason to exclude bad chip itself, in most cases the performance and poor inter-chip key, the key and our conventional single wire bonding into ABCDE five keys, and keys and poor I encountered following in time common reasons.