Characterization of PMDA-ODA Polyimide Films by External Reflectance Infrared Spectroscopy

Perez, Mario A.; Ren, Yuan; Farris, Richard J.; Hsu, Shaw Ling

doi:10.1021/ma00101a010

Cited by 16 publications

(30 citation statements)

References 15 publications

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“…This indicates that the orientation distribution of imide rings is almost isotropic around the chain axis, and it is independent of the molecular structures and the film sides. This result is consistent with previous studies22, 27 which reported that the imide planes are oriented parallel to the film surfaces only for very thin films.…”

Section: Resultssupporting

confidence: 94%

“…PIs can be easily processed into thin films by casting or spin‐coating of solutions of PIs or their precursors, that is poly(amic acid) (PAA) or poly(amic acid esters). There have been a number of studies for investigating chain orientation and anisotropy in their properties such as coefficient of thermal expansion11–13 (CTE), elastic modulus,11, 12 and refractive index 14–33. The magnitude of anisotropies in these properties basically depends on two factors: the intrinsic anisotropy and the degree of orientation of polymers.…”

Section: Introductionmentioning

confidence: 99%

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Molecular structure and thickness dependence of chain orientation in aromatic polyimide films

Terui

Matsuda

Ando

2005

J Polym Sci B Polym Phys

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Degrees of orientation of main chains and imide rings were quantitatively estimated for spin‐coated films of six kinds of aromatic polyimides (PIs) using polarized attenuated total reflection (ATR)/Fourier transform infrared (FT‐IR) spectroscopy. The degrees of chain orientation parallel to the film planes are significantly larger for the PIs having rigid structures than those having flexible structures, and the introduction of side groups decrease the degrees of chain orientation. In contrast, the rotational orientations of imide rings are almost isotropic for all PI films. Moreover, the film thickness dependences of the degrees of orientation were investigated for two kinds of rigid‐rod PIs having bulky trifluoromethyl (CF3) side groups in their diamine moieties. The degrees of chain orientation slightly decrease as the film thickness increases, whereas the rotational orientation of imide rings is independent of the film thickness. The degrees of chain orientation on the substrate sides significantly differ from the atmospheric sides of PI films. This difference was generated during thermal imidization because of tensile stress originated from the mismatch in thermal expansion coefficients between the substrates and the PI films. © 2005 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 43: 2109–2120, 2005

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Section: Resultssupporting

confidence: 94%

Section: Introductionmentioning

confidence: 99%

Molecular structure and thickness dependence of chain orientation in aromatic polyimide films

Terui

Matsuda

Ando

2005

J Polym Sci B Polym Phys

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“…All PI films prepared in this study exhibit good transparency in the visible region, and no scattering of light was observed. Although some rigid‐structured PIs exhibit semi‐crystalline nature,7, 8, 14, 25–28 no peaks related to crystalline components are observed in the WAXD patterns for the present PI films as shown in Figure 2. The shoulder peaks observed around 2Θ = 20° are assigned to amorphous halos.…”

Section: Resultsmentioning

confidence: 73%

“…On the other hand, the degree of chain orientation is directly related to the anisotropies in optical, dielectric, and mechanical properties of polymers. The degree of PI chain orientation have been studied using various methods such as birefringence measurements (Δ n ),9–12 polarized Fourier transform infrared (FTIR) spectroscopy,13–16 and dichloic ratios in absorption spectra using doped dyes 11, 17. In particular, Δ n has been widely used as the concise estimation of chain orientation because it is easily and precisely evaluated.…”

Section: Introductionmentioning

confidence: 99%

Coefficients of molecular packing and intrinsic birefringence of aromatic polyimides estimated using refractive indices and molecular polarizabilities

Terui

Ando

2004

J Polym Sci B Polym Phys

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Molecular structure dependences of the coefficients of molecular packing (Kp) and the intrinsic birefringence (Δn0) were investigated for aromatic polyimides (PIs) using a method based on the modified Lorentz–Lorenz equation and the Vuks equation. This method needs only average refractive indices and polarizability tensors ( ) for PI repeating units. αˆ was calculated using the density functional theory at the B3LYP/6‐31+G(d) theory level that was confirmed as optimal for PI repeating units. Because bent or kinked structures in main chain hinder the ordering of polymer chains, Kp decreases in cases that ether linkages are introduced in the main chain and that kinked‐structured dianhydrides are used. Introduction of side groups, trifluoromethyl (CF3) groups in particular, also causes decreases in Kp. On the other hand, the estimated values of Δn0 are proportional to the calculated anisotropy in αˆ (Δα/Vvdw), thus Δn0 can be well predicted by computation. The values of Δα/Vvdw are decreased not only by bent structures in the main chain (e.g., ether linkage), presence of side groups, but also by large fractions of imide rings in the polymer structures. The estimated values of Δn0 range from 0.338 to 0.470, which are much larger than the reported ones for optically transparent conventional polymers. © 2004 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 42: 2354–2366, 2004

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“…96͔͒ and the silicon-diode temperature sensor was attached onto the upper surface of the specimen to monitor the specimen temperature. [97][98][99][100][101][102] The LF method was executed by using T-7000 ͑ULVAC-Riko͒. 77 The ruby laser power was 6 J/pulse, the laser spot radius was 10 mm, and the decay filter was inserted to minimize the temperature increase on the front surface.…”

Section: Methodsmentioning

confidence: 99%

Thermal diffusivity of aromatic polyimide thin films by temperature wave analysis

Morikawa

Hashimoto

2009

Journal of Applied Physics

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Thermal diffusivity of alkali and silver halide crystals as a function of temperature J. Appl. Phys. 109, 033516 (2011); 10.1063/1.3544444 Thermal conductivity/diffusivity of Nd 3 + doped Gd V O 4 , Y V O 4 , Lu V O 4 , and Y 3 Al 5 O 12 by temperature wave analysisThe heat transport properties of aromatic polyimide thin films have become more important in the use for the electric insulation in the microelectronic devices with highly integrated circuits. The various kinds of measuring methods have been applied to obtain the anisotropic thermal conductivity and thermal diffusivity of thin films, however, if the specimens are soft and transparent, the conventional methodology requires highly advanced technology in preparing the specimens for the measurement and the results obtained vary widely. The purpose of this study is to apply the temperature wave analysis ͑TWA͒ method to measure the thermal diffusivity of thin films and spin-coated layers of aromatic polyimide in the thickness direction at various temperatures. The TWA is an absolute method to determine the thermal diffusivity by using the phase shift of temperature wave. We have performed measurements on the five different chemical structures of aromatic polyimide, including polyimide isoindoloquinazolinedione ͑PIQ͒, pyromellitic dianhydride and 4 , 4Ј-oxydianiline ͑PMDA/ODA͒, 3,3Ј ,4,4Ј,-biphenyltetracarboxylic dianhydride and p-phenylenediamine ͑BPDA/PPDA͒, 3,3Ј ,4,4Ј-biphenyltetracarboxylic dianhydride and 4,4Ј-oxydianiline ͑BPDA/ODA͒, and 3 , 3Ј ,4,4Ј-benzophenonetetracarboxylic dianhydride and 3,3Ј-diaminobenzophenone ͑BTDA/DAB͒. As a result, thermal diffusivity of thin films in a thickness range from 0.1 to 300 m at a temperature range from 10 to 570 K is obtained. The thickness dependence of thermal diffusivity of spin-coated layers of PIQ exhibits a good coincidence with the tendency of molecular anisotropy observed by attenuated total reflection Fourier transform infrared spectroscopy. In the low temperature below 20 K the amorphous PMDA/ ODA film exhibits a substantial increase, which can be understood by considering the phonon mean free path of amorphous systems as first noted by Kittel for inorganic glasses. The glass transition of BTDA/DAB is observed as a rapid decrease of thermal diffusivity. The results indicate the availability of TWA for the present needs of accurate but simple measuring technique to determine the thermal diffusivity of thin polymer films, which is strongly dependent on the chemical and anisotropic structures.

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Characterization of PMDA-ODA Polyimide Films by External Reflectance Infrared Spectroscopy

Cited by 16 publications

References 15 publications

Molecular structure and thickness dependence of chain orientation in aromatic polyimide films

Molecular structure and thickness dependence of chain orientation in aromatic polyimide films

Coefficients of molecular packing and intrinsic birefringence of aromatic polyimides estimated using refractive indices and molecular polarizabilities

Thermal diffusivity of aromatic polyimide thin films by temperature wave analysis

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