Micro Processing of Borosilicate Glass and Polymers

Presently, there is a growing demand from the industry for micro-processing of materials. In particular, for applications in the fields of microsystems technology, biotechnology and medical technology it is necessary to produce structures with dimensions down to the micrometer scale. This refers especially to materials that cannot or not in a sufficient quality be processed by conventional methods used in silicon technology. The excimer laser mask projection technique is a powerful tool for the generation of the required micro structures in a variety of materials. Due to its anodic bondability to silicon, Pyrex glass (7740 borosilicate Pyrex glass, Corning Inc.) is an interesting material for many applications in the field of microsystems technology. The possibility of microstructuring of Pyrex glass using laser technologies will enlarge the number of potential applications considerably. Micro holes in the glass represent the precondition for the generation of electrical through-connections. Such through-connections are beneficial for the minimization of the area of microsystems by transferring electrical ports to the backside of the system. Therefore more systems can be placed on a single wafer stack. The alternatively used ultra-sonic drilling technology is not suitable for this application due to the limitation to relatively large minimum hole diameters normally of over 200 microns.