Operating window for the peeling of polyimide film

Abstract

The peeling behavior of polyimide film coated on steel substrates was experimentally investigated and compared with existing models. An operating window for peeling, which is defined as a closed domain for steady and defect-free peeling, is presented in terms of peeling force versus residual solvent content. The window is bounded by two major defects: the film becomes too brittle for peeling at high peeling force, and stick-slip striation defect appears at low peeling force. There exists a critical residual solvent content below which the adhesion between the polyimide film and the substrate is too strong and then peeling is impossible. Existing models for predicting steady peeling and the onset of peeling defects have been modified and applied to setup the boundaries of the operating window. There also exists another operating window for drying of polyimide and is presented in the form of drying temperature versus film thickness.FIG. 12. The SEM images of stick-slip striation defects during peeling. (a) T ¼ 1208C, t ¼ 15 lm, v ch ¼ 10 mm/min, residual solvent content ¼ 11.9 wt% and (b) T ¼ 1808C, t ¼ 28 lm, v ch ¼ 2 mm/min, residual solvent content ¼ 7.3 wt%.

Thermal and mechanical properties of stretched recyclable polyimide film

“…The procedure for preparing the PIR was described previously by Wang et al, 47 which was based on a patented formulation. 48 The polymerization was carried out in one-step chemical imidization.…”

“…The drying temperature was set at 393 K and the drying time was around 500 s. 4. According to the peeling window found by Wang et al, 47 the PIR film could be peeled successfully if the solvent concentration of the PIR was between 6.5 and 16.5 wt %. In the present study, the solvent concentration of PIR samples was selected to be 12 wt %.…”

“…The drying temperature was set at 473 K for the first 2 h, and then raised to 523 K for another 2 h. The samples were completely dried and then removed from the oven after 4 h. 7. The residual solvent concentration of the PIR samples was measured with a thermogravimetry analysis (TGA7, Perkin-Elmer), following the procedure of Wang et al 47 The solvent concentration was found to be less than 0.5 wt % for all the samples.…”

Characterizing mechanical behaviors of a flexible AMOLED during the debonding process

“…They used the fracture toughness G c of the interface between the adhesive tape and the carrier board as well as the peeling model proposed by Kendall (1975) to calculate the peeling force required at different angles. In addition, Wang et al (2010) determined the force required to remove a PI thin film and demonstrated that the angle between the tip of the separation and the carrier board varies with the thickness of the thin film.…”