Deep wet etching process of Pyrex glass for vacuum packaging

In this paper, experiments were carried out to confirm that Copper layer was a feasible masking material during the wet etching process of Pyrex glass for vacuum packaging or 3D packaging. Our study revealed that the sputtered Chromium and Copper layers combination with the electroplated Copper layer is an ideal etching mask. The improvement of the corrosion solution produced some more reliable results. The maximum etching depth in the glass can be as high as 200 mu m along without pinholes and notch defects on the surface. It may have a long-term impact on MEMS development and applications.