Xenon Flash Lamp Lift-Off Technology without Laser for Flexible Electronics

This study experimentally investigated process mechanisms and characteristics of newly developed xenon flash lamp lift-off (XF-LO) technology, a novel thin film lift-off method using a light to heat conversion layer (LTHC) and a xenon flash lamp (XFL). XF-LO technology was used to lift-off polyimide (PI) films of 8.68-19.6 μm thickness. When XFL energy irradiated to the LTHC was 2.61 J/cm², the PI film was completely released from the carrier substrate. However, as the energy intensity of the XFL increased, it became increasingly difficult to completely release the PI film from the carrier substrate. Using thermal gravimetric analysis (TGA), Fourier-transform infrared spectroscopy (FTIR) and transmittance analysis, the process mechanism of XF-LO technology was investigated. Thermal durability of the PI film was found to deteriorate with increasing XFL energy intensity, resulting in structural deformation and increased roughness of the PI film surface. The optimum energy intensity of 2.61 J/cm² or less was found to be effective for performing XF-LO technology. This study provides an attractive method for manufacturing flexible electronic boards outside the framework of existing laser lift-off (LLO) technology.