Flow Performance and Its Effect on Shape Formation in PDMS Assisted Thermal Reflow Process

Abstract

A theoretical model is proposed to investigate the mechanism of shape formation in polydimethylsiloxane (PDMS) assisted thermal reflow. The thermal curing of PDMS is characterized by a dual-Arrhenius equation and its effect on the reflow process is discussed. It shows that due to the thermal curing of PDMS, the dynamic wetting and interface evolution are constrained successively. This is quite different from the traditional thermal reflow, and will result in unique flow performance, which will facilitate the abilities of the base constraint and shape retaining for the thermal reflow process. These advantages are critical to obtain well-defined microstructures in a simple and controllable way. Theoretical simulations of shape formation are in good agreement with the experimental results. These results provide a comprehensive understanding on PDMS assisted thermal reflow and offer a theoretical guideline for a facile yet versatile fabrication method for high quality microstructures.

Keywords

• microlens array
• thermal reflow
• flow performance
• numerical simulation