| Summary: | 碩士 === 國立臺灣科技大學 === 機械工程系 === 104 === Warpage is a common problem in the injection molding, rolling printing, and hot embossing of thermoplastic microfluidic chips. Warpage can greatly reduce bond quality and can even lead to chip failure. This study adopted an experimental methodology to investigate the influence of warpage on bonding quality. We created thermoplastic microfluidic chips with different degrees of warpage, by using a micromilling machine to fabricate five 4 inches brass mold inserts with various micro features. The micro features were used to vary the embossing pressure and thereby induce warpage of various degrees. The warped microfluidic chips, (25mm in width and 35mm in length, ) were bonded to pristine PMMA substrates using solvent. The bonded chips were subjected to leakage tests and burst pressure tests in order to characterize bond quality. Our experiment results clearly showed that chips with smaller warpage, (14.5μm with a STD of 4.3μm), could withstand burst pressure of 7.58 bars with 100% bonding success. The chips with larger warpage, (18.3μm with a STD of 3.7μm) and (23.2μm with a STD of 4.8μm, ) were able to withstand burst pressure of only 2 to 3 bars and presented a only 33% likelihood of forming a successful bond. In this study, warpage was shown to be a crucial factor in bonding quality, and wherein a pronounced warpage deteriorated bonding strength and reduced the likelihood of bonding successfully to the substrate to form thermoplastic microfluidic chips.
|
|---|
