The fabrication of nonplanar spin-on glass microstructures

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