Research On High-reliable Powder Blasting Micro-machining Technology Of Glass With Elastomer Mask

As one of the traditional fabrication process, sand blasting has the advantages of high processing rate, no heat effect, no spark and so on, which is particularly suitable for hard material processing. And its application in micro-machining of brittle materials, especially for glass, is the focus of researchers in recent years.Glass is mainly etched by wet etching and plasma etching, together with laser, electrical discharge machining and so on. However, when need deep etching of glass, all the methods above get each technical difficulties which cannot be overcome, as the high cost or the limited fabrication technology. Therefore, high rate and deep etching of glass processing technology is still the hot research and development field in Micro-Electro-Mechanical System. Sand blasting is designed for brittle materials processing, which is considered to be a promising technique.In this thesis, relying on the three-dimensional non-silicon micro-fabrication process of the lab, we designed and prepared the masks structure for glass sandblasting. What’s more, we designed and transformed the sand blasting machine, which is based on the traditional sand blasting cleaning machine, to be one dedicated glass micro-processing machine for the series experiments. Around the choice of the parameters of the blasting experiments and their effects on etching, we carried out the research as follows:Firstly, combining with the plastic etching and brittle etching theory, studying on the sandblasting etching mechanism and etch rate, and refer to the latest research process, we proposed the sandblasting etching solution. Then we studied the key coefficients in experiment, such as the gas flow field and sand material movement in the nozzle, which have the significant effect to increase the etching rate, through the computational fluid dynamics simulation software. Therefore, we identified the sandblasting initial experiments program.Secondly, utilizing the advantage of 3D non-silicon micro fabrication, the designed sand blasting metal and the poly-dimenthylsiloxane masks were fabricated respectively by developing new fabrication technology compatible with new materials. We modified the fabrication methods of the poly-dimenthylsiloxane mask structure to meet the requirements of the selective etching micro-machining. That is, through a precise cutting process, we successfully fabricated the micro structure of PDMS/SU-8 as an instinct mask, whose boundaries are exactly complementary with each other, which improved precision and mechanical strength of the mask.After that, we changed the etching conditions, specifically the air pressure, the scale of mask structure and the particles’size, which are the major parameters impact the etching rate and the etched structures’morphology. The experimental results show that the appropriate increment of the air pressure can help the etching process transit from the ductile etching to the brittle etching, which impact greatly on the erosion rate. Moreover, the surface morphology can be improved by decreasing the scale of the particles’ size from 30 micron to 20 micron. Preliminary results prove that the powder blasting micro-machining technology we have referred can meet the requirements to fabricate the array of 500μm-depth vias through the glass substrateThe glass sandblasting process with the high reliability poly-dimenthylsiloxane mask show a strong deep vias etching ability. By the further optimization of the processing procedures and the parameters, the sandblasting is likely to form a high-efficiency and deep etching processing for glass.