The fabrication of nonplanar spin-on glass microstructures

This paper presents a new application of spin-on glass to fabricate nonplanar dielectric structures (channel plate microstructures) with aspect ratios (i.e., ratio of channel length to channel width) of 20:1. A variety of microchannel geometries have been fabricated. The LIGA process is used to make nickel molds up to 150 mu m in height with mechanically planarized surfaces. Spin-on glass (SOG) is applied to obtain glass structures in nickel molds. A multiple dispensing/drying/curing process was developed resulting in crack-free SOG structures. Reverse electroplating is used to remove the nickel mold and release the glass structures.' The resulting freestanding glass microchannel plates (>100 mu m in height) demonstrated good electrical properties (400-V/mu m breakdown voltage) and good spatial definition.