Study On High Aspect Ratio LIGA Process

In this thesis, to increase the aspect ratio of LIGA process, several important influence factors were discussed, which includes the structure and performance of LIGA mask, X-ray intensity and X-ray spectrum of beam lines, the characteristic of PMMA resin and the micro electroforming parameters. The Au-PI mask and the Au-Si mask were designed by XOP and Origin software, after the difference between the spectrum of 3W1 and 3B1 beam line had been contrastively analyzed. Then some methods including optimizing the spectrum and intensity of 3W1 beam line and improving the performance of PMMA were put in force, and PMMA structure with aspect ratio 100 was obtained under these optimum conditions. Moreover, such steps as controlling PH, electrodepositing, using activator and a second cathode, and mending the power supply were taken to solve a series of problems coming into being during electroforming process correspondingly, for example, air holes, inner stress, and ununiformity of deposition. And then, metal structure with aspect ratio 30 was obtained in our laboratory. Eventually, a few micro parts with high aspect ratio were fabricated by LIGA process under the optimum condition. There were key parts of micro thruster, netlike nickel antielectron modulator, micro copper radiator, stainless steel micro components and many filter mediums with different shapes and dimensions...