Design Of Flexible Micro AlGaInP-LED Arrays And Study Of Flexible Electrode

As the advantages of high photoelectric conversion efficiency, small size, long life, low energy consumption, fixed wavelength and low heating, etc, Light Emitting Diode is widely used in many fields. In recent years, with the rapid development of medical, micro display and communication network and other fields, integrated micro LED arrays(?LEDs) has become the urgent demand of the market. In addition to the characteristics of the planar LED micro arrays, the flexible micro LED arrays can be applied on the object with curved surface, which has enlarged the application range of the ?LEDs. In this thesis, the structure design and the optimization of electodes connections in the flexible micro Al Ga In P-LED array are mainly presented, and the key technologies for fabricating device are researched. The work in this thesis includes five parts as follow:1. The structure and fundamental principle of Al Ga In P-LED were analyzed, including the properties of Al Ga In P-LED materials, the principle of luminescence. Besides, the light extraction of LED was discussed for improving efficiency and the current transmission in LED was calculated and analyzed in theory.2. According to the theoretical results and practical application requirements, the structure of the flexible micro Al Ga In P-LED array was designed.In experiment, the pixel size was set as 200?m×200?m. The arrays were designed as two dimensional arrays with 16 pixels×16 pixels, and the three-dimensional chain shaped electrodes were presented as the top electrode structure. Besides, required materials for fabricating the arrays was simply introduced.3. Bending deformation and stress of the electrode with the shape that three-dimensional chain was discussed. Theoretical analysis of the flexible array with three-dimensional chain shaped electrodes showed that the bending degree of this structure increased by 34% than that of the strip electrodes, and the three dimensional chain shaped electrode could be stretched and twisted.4. The process for fabricating flexible micro Al Ga In P-LED array was designed and the key technologies that segmenting filling the grooves and Ga As thinning were studied. The three dimensional chain shaped electrode was fabricated by the quasi LIGA technology and optimized electroplating conditions was presented.5. The sheet resistance of copper film was tested and discussed. The sheet resistance is the main component of the contact resistance of loops three dimensional chain shaped electrode and the variation range was 0.2-1.3m? as the tested and analyzed results showed.