FT-IR Study of the Imidization Process of Photosensitive Polyimide PMDA/ODA

Abstract

Fourier transform infrared spectroscopy (FT-IR) was used to study the cure reaction process of an ester-type photosensitive polyimide, PMDA/ODA films coated on silicon wafer substrates. In the in situ high-temperature FT-IR study carried out in vacuum, all the characteristic peaks of imide and the crosslinkable group were observed to decrease gradually with an increase in temperature. The completion of the imidization reaction is at ∼270 °C. Our result shows that the ester-type photosensitive polyimide can be cured at a much lower temperature than previously reported. The imide peak δas(C, C > NC) at 588 cm−1 was used to follow the imidization process, and the result agrees well with that obtained by using another imide peak v(C–N–C) at 1378 cm−1. The film shrinks by one third during the cure process, and the temperature dependence of the film thickness shows excellent agreement with the “imidization degree”.

Investigation of Interface Bonding Mechanisms between Glassy Carbon Microelectrodes and Polyimide Substrate through Fourier Transform Infrared Spectroscopy

“…[25][26][27] The presence of an aromatic backbone is suggested by the characteristic tetra-substituted benzene peaks at 1970 cm −1 , 1650 cm −1 (overtones), and 800 cm −1 .…”

“…Figure 1 shows a neural probe with lithographically patterned GC microelectrodes supported on a polyimide substrate where the interface bond between GC and polyimide is expected to enable a longterm implantation. 27 For a detailed investigation of this interface, test structures that are a good representation of such probe but with larger diameter microelectrodes and that meet standards for sample preparation for chemical testing were fabricated. The test structures are 5 circular microelectrodes 2.5 mm in diameter and 3 mm center to center spacing, arranged in a circular manner in 1 cm × 1 cm die.…”

“…27 Thus, throughout the rest of this study, we assume the PMDA-ODA configuration of polyimide. Figure 5 also outlines the functional groups that are likely to participate in bonding: hydroxyl, carbonyl, and ether groups.…”

Morphology and thermo‐mechanical properties of compatibilized polyimide‐silica nanocomposites

“…The hydrolysis of corboxylate groups of amic acid might be slow 34 if the metal oxide precursor remains bonded to amic acid until all alkoxide groups have been hydrolyzed off. The curing conditions in the present work were improved by enhancing the curing time at the temperature where the imidization process has been reported 35,36 to be the maximum. FTIR measurements were used to monitor the imidization and the silica network formation, both of which occur simultaneously.…”

“…The above-mentioned absorption bands for polyamic acid disappeared, and new bands appeared at 1776.8, 1721.89, 727.61 cm Ϫ1 , and 1371.42, which correspond 35 to imide carbonyl (CAO) asymmetric and symmetric stretching, bending, and the imide band (C-N), respectively, and confirmed the formation of polyimide. The band corresponding to the aromatic C-H stretching vibrations, which appears in the range 3000 -3100 cm…”