Research Of The Key Technologies Of LED Application

As a typical green lighting technology, LED has quickly gained popularity as an illumination device with its superiority in power consumption, environmental friendliness, flexibility, size, and durability. Tempted by the great market potential of LED products, many countries have launched their own semiconductor illumination development programs in order to acquire a share in this emerging area and gain some advantages for the future. With years of development, China has become a major link in the chain of the global semiconductor illumination industry. However, our competitiveness is still lacking and the reasons for this are twofold:on one hand, most Chinese companies are engaged in the low value-added part of the value chain:LED packaging, while the high value-added upstream parts are monopolized by the American and Japanese companies; on_the other hand, we haven't mastered the key application technologies for the high value-added downstream part. In this thesis, we shall focus on these key technologies which are used in the practical application, such as thermal management, control and driver circuitry, and electro-mechanical integration, and propose our solutions to these problems which could help enhance the competitiveness and add-value of domestic LED products.First, the thermal management problem is considered. Based on a thorough investigation of the existing thermal design techniques, We improved the conventional polymer-based insulated metal substrate (IMS) PCB techniques and flat heat pipe techniques, and applied the magnetron sputtering technology which has been widely used in the fields such as aerospace, household appliances and handicraft, an anodized insulated aluminum substrate PCB technique and a vapor chamber substrate PCB technique are realized. Both the theoretical analysis and the experimental studies show that our techniques will have better thermal management capabilities.Our second topic is the LED control and driver circuitry design problem. After an extensive study of the existing design techniques, we developed a PT4115-based LED driver. Experiments are performed to analyze two major issues of the mainstream LED driver technology, which are how to reduce power consumption of the circuit and how to achieve more precise current control. Based on the experiment results, we proposed a solution to each of the two issues for the IC chip designers.We also presented the overall design of the stereomicroscope's LED lighting and focus knobs control system, including both the hardware architecture and program flow, and this was used as an example to illustrate the electro-mechanical integrated design methodology for LED products, which could increase their add-value and intelligent level.