An Experimental Study On Thermal Bonding Effects Of PMMA Based Micro-devices Using Hot Embossing

Abstract

Basic configuration and functioning of various subsystems of a developed HEMM system for thermal bonding are discussed. The bond strength and micro channel geometry degradations dependence on controlled process parameters in thermal bonding using hot embossing has been investigated. The process parameters examined were bonding temperature, bonding or applied load and holding time. Polymeric substrates with different feature dimensions and thickness were embossed and bonded using hot embossing technology. The feature dimensions before and after bonding were examined to assess the geometry changes as functions of the bonding process. This assessment could provide guidance during the design phase of micro-fluidic devices considering the bonding step. The results from the experiments show that high bond strength can be obtained at higher temperature and pressure and longer holding time. Also, to obtain minimum degradation, the bonding temperature and pressure should be kept low with longer holding times. The experiments also suggest combination of input parameters to obtain good bond strength and minimum degradations. ANOVA analysis of the experimental data was performed to find the regression models to estimate the outputs knowing the controlled inputs and to find the sensitivity of controlled process parameters on bond strength and channel degradations. The models are linearized to estimate the input process to obtain the desired bond strength or channel geometry.