Rheological characterization and process analysis.(Hot embossing in microfabrication, part 2)(Statistical Data Included): An article from: Polymer Engineering and Science

This digital document is an article from Polymer Engineering and Science, published by Society of Plastics Engineers, Inc. on March 1, 2002. The length of the article is 3773 words. The page length shown above is based on a typical 300-word page. The article is delivered in HTML format and is available in your Amazon.com Digital Locker immediately after purchase. You can view it with any web browser.

From the author: The dynamic shear viscosity and the transient extensional viscosity of polycarbonate (PC), polymethyl methacrylate (PMMA), and polyvinyl butyral (PVB) were measured at temperatures near and far above their glass transition temperatures. The temperature sensitivity of rheological properties was used to explain the displacement curves during embossing. Numerical simulation of the embossing process was also carried out to compare with the observed polymer flow patterns. It was found that the simulated flow pattern during isothermal embossing agrees fairly well with the experimental observation. The deviation between the simulated and experimental results at the late stage of embossing may be due to air entrapment between the mold feature and the polymer substrate. For non-isothermal embossing, the observed flow pattern can also be reasonably simulated, i.e. the polymer flows upward along the wall of the heated mold feature, and then compresses downward and squeezes outward. Temperature sensitivity of the dynamic shear viscosity and the transient extensional viscosity is similar for all three polymers. This correlates well with the initial displacement curves in isothermal embossing. Over a longer time, the strain hardening effect of the transient extensional viscosity seems to play a major role in the displacement curves.

Citation Details
Title: Rheological characterization and process analysis.(Hot embossing in microfabrication, part 2)(Statistical Data Included)
Author: Yi-Je Juang
Publication:Polymer Engineering and Science (Refereed)
Date: March 1, 2002
Publisher: Society of Plastics Engineers, Inc.
Volume: 42 Issue: 3 Page: 551(16)

Article Type: Statistical Data Included

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