Preparation of wafer-level LED packaging used uniform micro glass cavities by an improved Chemical Foaming Process (CFP)

Micro glass cavity has very important research values in many fields including Lighting Emitting Diode (LED) packaging, atomic devices, MEMS packaging and so on. In this study, an improved Chemical Foaming Process (CFP) have been investigated and uniform wafer-level micro glass cavities, which could be used in wafer-level LED packaging, have been prepared successfully by the proposed process. First of all, the fabrication process is introduced. Then the prepared uniform wafer-level semispherical glass cavity has been characterized by Atomic Force Microscopy (AFM) and mechanical shock test. And the result shows that the surface roughness of glass cavity is quite smooth which suits for optical applications as well as many other applications. At last, LED chip packaged with semispherical micro glass cavity on silicon substrate is presented.