Hot embossing in microfabrication. Part II: Rheological characterization and process analysis

Yi Je Juang, L. Lee James, Kurt W. Koelling

Research output: Contribution to journalArticle

99 Citations (Scopus)

Abstract

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.

Original languageEnglish
Pages (from-to)551-566
Number of pages16
JournalPolymer Engineering and Science
Volume42
Issue number3
DOIs
Publication statusPublished - 2002 Mar 1

Fingerprint

Microfabrication
Polymers
Flow patterns
polycarbonate
Shear viscosity
Viscosity
Polymethyl Methacrylate
Polycarbonates
Polymethyl methacrylates
Strain hardening
Temperature
Computer simulation
Substrates
Air

All Science Journal Classification (ASJC) codes

  • Chemistry(all)
  • Polymers and Plastics
  • Materials Chemistry

Cite this

@article{9e7dd72cf5fb46e1b6a8b23c5d5df545,
title = "Hot embossing in microfabrication. Part II: Rheological characterization and process analysis",
abstract = "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.",
author = "Juang, {Yi Je} and {Lee James}, L. and Koelling, {Kurt W.}",
year = "2002",
month = "3",
day = "1",
doi = "10.1002/pen.10971",
language = "English",
volume = "42",
pages = "551--566",
journal = "Polymer Engineering and Science",
issn = "0032-3888",
publisher = "John Wiley and Sons Inc.",
number = "3",

}

Hot embossing in microfabrication. Part II : Rheological characterization and process analysis. / Juang, Yi Je; Lee James, L.; Koelling, Kurt W.

In: Polymer Engineering and Science, Vol. 42, No. 3, 01.03.2002, p. 551-566.

Research output: Contribution to journalArticle

TY - JOUR

T1 - Hot embossing in microfabrication. Part II

T2 - Rheological characterization and process analysis

AU - Juang, Yi Je

AU - Lee James, L.

AU - Koelling, Kurt W.

PY - 2002/3/1

Y1 - 2002/3/1

N2 - 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.

AB - 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.

UR - http://www.scopus.com/inward/record.url?scp=0036502497&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=0036502497&partnerID=8YFLogxK

U2 - 10.1002/pen.10971

DO - 10.1002/pen.10971

M3 - Article

AN - SCOPUS:0036502497

VL - 42

SP - 551

EP - 566

JO - Polymer Engineering and Science

JF - Polymer Engineering and Science

SN - 0032-3888

IS - 3

ER -