Laser-induced broad-spectrum strong absorption multiscale carbon-based nanofilms for photonic debonding based on the spatial confinement effect

The photonic debonding process demonstrates significant potential for application in large-size wafer-level/panel-level advanced packaging owing to its advantages of high throughput, high precision, and ease of manipulation. However, conventional metal-based release materials still face the challenge of low photothermal conversion efficiency, which leads to the photonic debonding process not only requiring high-power equipment, but also suffering from time- and energy-consuming as well as safety concerns. Here, we propose a method to prepare laser-induced graphite films (LIGF) in situ on glass surfaces based on the spatial confinement effect. Thanks to the unique “flat bone” multiscale nanostructure, the absorption rate of LIGF is higher than 95% in a wide wavelength band of 200–1100 nm, which dramatically improves the photothermal conversion efficiency of the released material. Under pulsed flash irradiation, the LIGF-based release layer absorbs photon energy and generates a transient high temperature, which causes thermal decomposition of the organic adhesive material in contact with the release layer, enabling rapid separation at the interface of release layer and adhesive layer (R/A). Compared to metal-based release materials, LIGF is able to reduce the photonic debonding threshold of the same bonding pair by ~40%, and the R/A separation interface exhibits the advantages of no carbon debris and easy cleaning. It is noteworthy that the LIGF release layer remains virtually undamaged after photonic debonding and allowing multiple reuses. In addition, the ultra-low transmittance (≤0.02%) of the LIGF release layer prevents light leakage-induced damage to the device surface. The prepared LIGF release material demonstrates exceptional thermal and chemical resistance, ensuring robust industrial adaptability. These properties make it a promising candidate for large-scale wafer-/panel-level photonic debonding in advanced packaging applications.