Enhancement of Mechanical and Thermal Properties of SU-8 Photoresist with Multilayer Woven Glass Fabric Based on Micromachining Technology

Abstract

SU-8 photoresist has been more and more widely used as a structural material in micro electromechanical system (MEMS) because of its low cost and excellent biocompatibility. However, the inferior mechanical and thermal performances immensely impinge the reliability of the MEMS device based SU-8 and accordingly restrict its application. Here we report the mechanical and thermal performance of SU-8 reinforced by the multilayer glass fabric with the MEMS technology. The finite element simulation and specific experiment are conducted, which confirm that the reinforced SU-8 composites have a 281% increase in Young's modulus and a 64% decrease in coefficient of thermal expansion (CTE) compared with pure SU-8. Additionally, the improved mechanism has also been analyzed, including the excellent interface bonding between the SU-8 and glass fabric, and the high-bond energy of Si-O-Si chain structures in glass fabric. Furthermore, the glass fabric reinforced SU-8 could still possess a high light transmittance to maintain the ability of lithography patterning. Therefore, it is believed that the strategy proposed here may satisfy higher requirements of MEMS devices, which guarantees its practical applications in the functional microstructures.